: Answer the 1Million Question: Where is the air ride control relay located?



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EXTodd
06-17-08, 02:18 AM
My friend has pretty much troubleshooted my no "compressor on" problem to the relay on my '02 EXT. We used a test light to the power (red wire) going to the compressor and we could not get anything. I stood on the back bumper trying to activate the compressor and we got no power. So I went to the local Autozone and the only info they had in the computer is that the relay is possibly located under the driver seat.

It's a pigtail relay, Niehoff part # PS38281 "Accesory Relay Connector". It's a plug with 5 wires coming out of it.

Can somebody please tell me where this is located in my 2002 EXT? Thanks in advanced.

250motorsportz
06-17-08, 02:27 AM
I'd love to know the answer to this too.

EXTodd
06-17-08, 04:49 AM
I'm making headway. If your Escalade is an EXT the Suspension Control Module is under one of the rear seats otherwise it's behind the rear right panel closest to the rear hatch. You have to remove the rear panel to get to it.

ewill3rd
06-17-08, 09:44 AM
It should be located:


On the left side of engine compartment near the Fuse Block - Underhood

You might have to pull the housing off of the electrical center to see it.
It should have a brown, light blue, and two red wires going to it.

You need my paypal account info to send me the million? :lol:
Let me know if you can't find it.
You could still have other problems.

EXTodd
06-17-08, 01:22 PM
It should be located:


You might have to pull the housing off of the electrical center to see it.
It should have a brown, light blue, and two red wires going to it.

You need my paypal account info to send me the million? :lol:
Let me know if you can't find it.
You could still have other problems.

Thanks ewillr3d! Are you saying it's the big fuse box or below it? Do you have a diagram that you could post? Thanks bro, I know I appreciate this a lot and I'm sure many others here do too. Is this where the actual relay is? Do you know the part # for the relay?

ewill3rd
06-17-08, 06:50 PM
I don't know the part number, I tried to find a picture but I couldn't. I don't have any in the shop right now.
There is a plastic cover over the main fuse block under the hood, sometimes the relays are mounted close by, sometimes they are under the cover.
To remove the cover, remove the left side frame brace (four 13mm head bolts) and then release the hook tabs down on the sides of the cover, pull it up and look for the relay.
There could be a couple mounted there, just check the wire colors for your relay. It should have a number on it.

Our relays don't really fail that often, be sure to check the maxi fuses and related system fuses in the main fuse block.
The relay (power to compressor) is fed from the "stud 1" fuse and the "ign 3" fuse feeds the control side of the relay.

EXTodd
06-18-08, 12:01 AM
I don't know the part number, I tried to find a picture but I couldn't. I don't have any in the shop right now.
There is a plastic cover over the main fuse block under the hood, sometimes the relays are mounted close by, sometimes they are under the cover.
To remove the cover, remove the left side frame brace (four 13mm head bolts) and then release the hook tabs down on the sides of the cover, pull it up and look for the relay.
There could be a couple mounted there, just check the wire colors for your relay. It should have a number on it.

Our relays don't really fail that often, be sure to check the maxi fuses and related system fuses in the main fuse block.
The relay (power to compressor) is fed from the "stud 1" fuse and the "ign 3" fuse feeds the control side of the relay.

Yeah, STUD1 is the first fuse I checked and it's good. So you're saying the relay is actually under the main fuse block under the hood? Bellevue, WA Cadillac helped me locate the actual relay today and I bought it from them. tyco brand, part # 12193601. It's the same basic relay for the fuel pump, A/C, etc. Nothing special. Yeah, $40 for a relay is dumb but they printed out the schematics and really tried to help me. Even the service tech could not tell me exactly where the relay was either, he was stumped. He thought it may be by the SLC unit in the rear passenger side panel behind the seat. But I think you are probably correct as most relays are at or around the fuse block.

I'm going out to the EXT shortly so I will check back here and tell you what I find.

Yeah, I'll prolly owe ya $1M so I need your PayPal info. :blurock:

EXTodd
06-18-08, 03:00 AM
Well first off the dude at the service counter was wrong about that being the same relay as the fuel pump, A/C, etc. Different sized relay, not the same at all. The relay I got today is larger. tyco brand, part # 12193601. I did notice the relay I bought has a sleeve molded into one side of it so it can be mounted onto something. So I would assume that it doesn't go in a fuse block.

Ok, out to the EXT......

I'm back....

I did find a similar relay mounted to the side of the plastic housing at the bottom of the fuse box. Just like ewill3rd said. I thought this may be the same part but I read OEM part # 12193503 off the relay. What is this one for? So I suppose my next step is to take the support brace off and lift the fuse block plastic housing as ewill3rd instructed me.

ewill3rd, did we troubleshoot this correctly? We didn't pull any codes from the computer with the OBD2 reader. We tried to activate the compressor and we used a test light to see if there was current. We got nothing. Last Sunday when I was in the house getting something my buddy was outside troubleshooting and he swears he heard the compressor kick on after turning the ignition to on. He yelled to me and I ran outside and it stopped before I got out the door. I would lean to believe him because he knows more about cars than me and he also owns a Chevy Trailblazer with the same air ride system. So he knows the sound of the compressor.

EXTodd
06-18-08, 03:04 AM
I believe I also found the suspension control module and something else under the rear driver side seat with a plastic housing around it. The larger aluminin cased ECU looking device must be the SLC? It says Delphi OEM Service # 15081997. There is also a smaller black plastic unit to the side. It says Bosch # 15068175. What's this?

EXTodd
06-18-08, 03:22 AM
It should be located:


You might have to pull the housing off of the electrical center to see it.
It should have a brown, light blue, and two red wires going to it.

You need my paypal account info to send me the million? :lol:
Let me know if you can't find it.
You could still have other problems.

Yeah, those are exactly the wire colors that I saw but going into a blue tyco relay #12193503. Did the parts guy give me the wrong relay or are these relays interchangable? He gave me a black tyco relay #12193601. Looks like the same size.

ewill3rd
06-18-08, 09:43 AM
Wow, sorry I am not keeping up with you... :lol:

The parts catalog is pretty worthless when looking up relays sometimes. Usually I find the relay I want to replace and give them the old number to get the new one.
It shouldn't be the same as a fuel pump relay.
If the exterior dimensions are the same it will plug in but sometimes the circuitry and contacts inside can be different based on the usage. One might hold up to more switching current than another.

As for diagnosing it, there are steps you should take. I can give you a couple ideas but I am not sure if that will completely diagnose the problem.
Any controlled relay is easy to check, provided the criteria are met for activation.

For example, to drop voltage straight to the compressor to see if it will come on you could use a jumper wire from one of the red wires to the other.
That is what the relay does when it is activated. It should dump power to the back so you can check with a test light to see if the wires are broken under the truck somewhere.
You can use a test light to check for voltage on the control circuit (brown wire), do you still have the schematics?
The suspension control module grounds the blue wire to activate the relay. You could backprobe the blue terminal with the relay connected, it may provide enough of a ground to activate the relay and if everything is connected you should hear the compressor kick on.
The module under the rear seat is indeed the suspension control module and it is in charge of the level ride.

Realistically you could have issues with the height sensor, wiring, module, or the compressor itself.

Based on what you have posted so far I would say jumper from red to red at the relay and see if the compressor comes on and go from there.
I don't see many failures on that system so I can't really tell you where to go based on a high failure rate of any particular part.
I might only have a chance or two to check back today so I apologize if I can't get back to you quickly but I'll check back if you have more questions.

EXTodd
06-18-08, 11:55 PM
Hey, thanks a lot ewill3rd. I will do as you say as soon as I can get some time. Probably this Saturday. You have given me great information and I am thankful.

ewill3rd
06-19-08, 08:18 AM
You are most welcome.
:D

EXTodd
07-01-08, 02:10 AM
Wow, sorry I am not keeping up with you... :lol:

The parts catalog is pretty worthless when looking up relays sometimes. Usually I find the relay I want to replace and give them the old number to get the new one.
It shouldn't be the same as a fuel pump relay.
If the exterior dimensions are the same it will plug in but sometimes the circuitry and contacts inside can be different based on the usage. One might hold up to more switching current than another.

As for diagnosing it, there are steps you should take. I can give you a couple ideas but I am not sure if that will completely diagnose the problem.
Any controlled relay is easy to check, provided the criteria are met for activation.

For example, to drop voltage straight to the compressor to see if it will come on you could use a jumper wire from one of the red wires to the other.
That is what the relay does when it is activated. It should dump power to the back so you can check with a test light to see if the wires are broken under the truck somewhere.
You can use a test light to check for voltage on the control circuit (brown wire), do you still have the schematics?
The suspension control module grounds the blue wire to activate the relay. You could backprobe the blue terminal with the relay connected, it may provide enough of a ground to activate the relay and if everything is connected you should hear the compressor kick on.
The module under the rear seat is indeed the suspension control module and it is in charge of the level ride.

Realistically you could have issues with the height sensor, wiring, module, or the compressor itself.

Based on what you have posted so far I would say jumper from red to red at the relay and see if the compressor comes on and go from there.
I don't see many failures on that system so I can't really tell you where to go based on a high failure rate of any particular part.
I might only have a chance or two to check back today so I apologize if I can't get back to you quickly but I'll check back if you have more questions.


I did what you said ewill3rd. You are correct, the compressor kicked on when we jumped red to red. So what we did was install a push button switch into the fuse block and t-spliced into the blue wire and grounded it at that support brace right above the fuse block housing. We concluded that the relay was good because we ran power and ground where red to red connects (@ pin 30 & 82) on the relay and it clicked (opened). So we are thinking it may be the ride height sensors causing the issue? If it was the suspension control module wouldn't something show up in the message center and wouldn't we get a code when we scanned it with the OBD2 reader?

Ok, even when I manually start the compressor and let it run it doesn't load air into the rear shocks and raise the rear end. I hooked my boat up to the hitch to add weight and I ran the compressor for a few minutes straight and it did nothing at all. All I hear is the compressor running and that's it. Is there a valve to the air shocks that is controlled by the suspension control module? Are my shocks shot? If the shocks were bad wouldn't the truck sag at the rear?

I am now totally confused because I thought we at least manually overrode the system to at least make it possible to tow the boat this weekend. I want to fix this right and have the ALC work normally. We will take the rear wheels off and adjust or replace the ride height sensors because we're thinking that is where the problem is. I just want to know what to buy because I am ready to fix this problems once and for all. I will buy new rear shocks from Arnott or whatever is needed. I just needs some insight and help here guys cause I thought we had a work around today but we're no better off than we were a few weeks ago. We can hear the compressor running when we push the button now but nothing else.

Thanks for all your help ewill3rd. I still need your expert advice cause I am at another road block.

ewill3rd
07-01-08, 07:31 AM
Do you know how to remove the air lines from the shocks?
If so you could see if there is any pressure getting to them. You could run the risk of having the truck sit lower if the compressor is not working and there is pressure in the system.
Even though the compressor may run there is still an exhaust solenoid in there, it could be stuck open or some variant.
I'd have to pour over the schematics to see what could be your issue otherwise. I'd say the relay is probably fine based on the testing you have done so far.
It might be hard for me to try to find time to help you further but if you want I'll sure try.
Just bump this topic a couple times and I'll see it as a reminder. If you don't hear from me send me a PM.

I'll have to see what kind of tests you can do without a scan tool.

EXTodd
07-01-08, 01:23 PM
Thanks a lot ewill. Can you tell me how to remove the air lines from the shocks? Is it difficult? We can see that there is still air pressure in the shocks so why doesn't it deflate and sag the rear end if the exhaust solenoid is possibily open? Thanks for your help.

EXTodd
07-01-08, 02:26 PM
Would the OBD2 reader pick up codes from the suspension control module if it was malfunctioning? Or does it only read codes from the main ECU?

ewill3rd
07-01-08, 10:32 PM
To relase the air lines, you just rotate the metal clip 90 degrees and then pull them off. The clip needs to be out of the groove so you just have to spread it by rotating it.

A standard OBD code reader won't access the suspension module to read data without special software that it probably won't have.
You'd need a Tech 2 to check for codes and data :(

If the exhaust valve was open it would indeed sit low.
I am sorry I am so busy, holiday week and I have a line of cars that have to be done by Thursday!
Thanks for your patience.

03fatboy
07-01-08, 10:44 PM
I think it is time for a trip to the dealer they can most likley fix this problem very easily it is a pretty simple system.

EXTodd
07-16-08, 10:13 PM
I haven't had time to mess with this lately but thanks for your help ewill. What would be the reason why the pump is not loading the air shocks even though we here the compressor working? So basically there is just an exhaust valve that releases air from the shocks but no valve controlling the the air going into the shocks?

ewill3rd
07-17-08, 08:20 AM
I am not sure how they specifically designed it. They probably do use a valve to maintain pressure and one to release pressure but I'd have to look over the stuff in the manual.
They really don't fail that often. Over the years the level sensors have changed more than the control system and compressor.
There are other things that can happen too, you could have a leaking line... when the compressor runs for a long time and sees no difference in the ride height it will shut down to protect the compressor.
It could be a wiring problem, a control problem, or an output problem... impossible to tell without having the vehicle in my bay.

EXTodd
07-19-08, 11:23 PM
ewill,

I found out why air wasn't loading into the shocks. I inspected the compressor yesterday and I noticed when my friend reinstalled the compressor he kinked/looped the line. I unlooped it and now air pressure loads into the shocks just fine. I still have to do it manually but this is a relief because I can tow the boat again.

So now I think I pretty much concluded the sensors need to be adjusted. I think they got bent? We are taking the rear wheels off next week to examine them.

ewill3rd
07-20-08, 08:12 AM
Ahhh progress.... feels good!

Keep us posted when you find the root cause.

dstinson
07-22-08, 12:02 AM
I feel like this is a support group of some nature, anyway my name is David and I too have an air ride problem. after reading this review from page one I went to the dealership and got my relay ($48), but I still have the "my compressor is not working" problem. EXTtodd suggested I put my comment\problem on the board to discuss. The dealership at one point told me they jumped the compressor to make sure it was working and it was. They aren't that helpful because my truck is lowered and the rods are bent in the rear (per directions from the kit I got). So anyway EXtTodd's next suggestion to me what was to put power to the compressor and see if I can get it to click on. Do I need to drop the compressor in order to put power directly to it, and do I just run a wire straight from the battery all the way to the back. And lastly will it click on if it senses its not low enough (from the weight). This is quite frustrating as I only drive the truck with my trailer and the rest of the time it sits in the garage, I just want my air ride to work.

PS I find this forum quite helpful at times, thanks everyone.

EXTodd
07-22-08, 02:12 AM
dstinson,

Read this from earlier in the thread:

I did what you said ewill3rd. You are correct, the compressor kicked on when we jumped red to red. So what we did was install a push button switch into the fuse block and t-spliced into the blue wire and grounded it at that support brace right above the fuse block housing. We concluded that the relay was good because we ran power and ground where red to red connects (@ pin 30 & 82) on the relay and it clicked (opened).

The ride control relay is located on the outside of the fuse block. So if you are looking at the fuse block from the driver side it is located on the far side, toward the engine. It's clipped to the outside of the plastic fuse block housing. Easy to find thanks to ewill of course.

ewill3rd
07-22-08, 07:56 AM
Yeah, if you go back up and read (I know it sucks) there are good instructions on where to find the main relay and how to jumper accross it to activate the compressor.

dstinson
07-23-08, 10:07 PM
I found the relay (thanks to this post) and brought it with me to the dealership, I have part 12177235 (03 escalade) and that part number references another similar part number and I bought that. I jumped 87 & 30 (per the contacts on the relay) and I can see sparks but I do not hear a clicking. I used 2 wires holding a 30amp fuse in-between to make the contacts. So I wanted to see if the compressor would kick on if I gave it direct power, or is jumping it, giving it direct power? Will I hear the clicking from the engine bay or do I need to be right up to the compressor?
thanks, one day before I die I will have this working

ewill3rd
07-23-08, 10:32 PM
If it is sparking it might be working, you'll probably have to have someone back by the left rear wheel to hear whether or not the compressor is kicking on.
Jumpering it should put power to the compressor.

EXTodd
07-25-08, 02:48 AM
Ahhh progress.... feels good!

Keep us posted when you find the root cause.


Thanks ewill. You have been a great help to me. I feel like we're friends now... :drunkpair:

ewill3rd
07-25-08, 07:36 AM
Thanks, glad to help :cloud9:

I'll feel better when this is fixed for good.
I am sure you will too... since it is your truck!


Now..... about that million dollars.... :lol:

sashadg
07-29-08, 11:46 AM
I have been trying to locate a source that tell me what I need to do in order to disable the compressor system so that I don't get a trouble code or check engine light.

My Escalade is lowered with Eibach 3" and has been so for about 40K. The original shocks work but can't control the vehicle any longer. My wife is all over the place on the frwy's especially with people in the car. I have had the Bilsteins on a Yukon and it was very nice along with the sway bars, which also is on the list of to do's.

ewill3rd

Can you direct me to a fuse or what I can do here?

Thank Scott

ewill3rd
08-01-08, 10:13 AM
I can't really help you disable it, not something I do often... or ever for that matter.

You'd have to make a lot of modifications, you'd probably be better off paying someone to fix it properly.
It's not worh your wife having a wreck to save the money to fix it right is it?

EXTodd
08-02-08, 03:18 AM
Thanks, glad to help :cloud9:

I'll feel better when this is fixed for good.
I am sure you will too... since it is your truck!


Now..... about that million dollars.... :lol:


You said that you have a PayPal account...right? :worship:

ewill3rd
08-02-08, 10:40 AM
Yeah, I have a paypal account.. :lol:

sashadg
08-04-08, 11:10 AM
ewill3rd

So going in an replacing the original shocks with aftermarket shocks could be dangerous? In what way?

Thank you for for reply


Scott

ewill3rd
08-04-08, 02:40 PM
It wouldn't be necessarily "dangerous" but it would be complicated to make the computer not display the message.
The suspension module would be looking at the level sensor and trying to run diagnostics on the compressor so you'd get a warning light.

Sorry if I came off wrong earlier, but the simplest procedure would probably be to fix the system properly than to try to work around it.
I am not sure if anyone has done this before on Escalade, I am sure it can be done, but time and money wise I think your best bang for the buck would be to get it fixed.
Particularly since you stated that you are concerned for your Wife's safety due to handling issues with the malfunctioning system.

esca lade uk
01-28-09, 09:10 AM
EXTtodd did you resolve the matter with your compressor not working? I am having the same problem. Did it turn out to be the height sensors?

sk7
07-19-09, 11:25 PM
Great post! I was able to locate the relay for the compressor, here is a picture.

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade114.jpg

I am also trying to diagnose a not running air compressor. Took it off the truck, jumped with battery, runs good. Cleaned and reinstaller, jumped at the relay, compressor comes on. I am getting no ground signal from the suspension control module while tuning on ignition. Can a stored DTC prevent the compressor from coming on? The service stability system light is on, comes on as soon as I drive for more than 10-15 feet, after 2 buzzing sounds from under the truck (seems to come from the ABS, brake pedal pulsates with the sound). Will Innova's 3150 enable to read those codes?

Relay Pic:

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade115.jpg

Relay unplugged showing harness:

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade117.jpg

GM's SI manual says the suspension control module needs to be calibrated (upon replacement)? I had the complete interior out of the truck for a few months, and its been driven on and off towings without the module.

sk7
07-21-09, 10:41 PM
I suspected a broken wire or ? from the suspension control module, so I tested what I could from the module itself (12V, 5V ref, IGN, GND) and the blue wire to the front relay, all checks out ok. Module is located behind rear heater-ac system back right side. Will post pics tomorrow... I wish I had acess to a GM tech 2 scanner. :worship:

luxurylife33
07-21-09, 11:11 PM
i have a "service ride control" message and my shocks in the back are DUMPED and the compressor wont turn on.......and I jumped my relay and got the compressor to kick on. What should I check for next? is the relay damaged? im guessing some sort of sensor maybe?

sk7
07-22-09, 12:04 AM
Your relay is most likely good. I was glad to hear the compressor running when I jumped the contacts together tho. Do you have 12V ignition at the relay when key on? Brown wire if I remember right (Im at work right now, don't have the wiring diagrams with me). Blue wire is negative trigger from the suspension control module. Maybe your truck has the same problem as mine. My rear shocks are brand new. Dunno where the SCM is located on the EXT. Blue trigger wire is in the middle plug.

luxurylife33
07-22-09, 12:30 AM
At the relay on my 03 EXT is 2 blue wires a red and a black.... black is a constant ground, red is a constant + and when the ignition is turned on, it is no longer positive (maybe this is a problem?), one of the blues goes directly to the compressor since i jumped the red and blue while the car was off and the compressor kicked on..... The SCM is located under the rear seat on the ext.... im clueless as to what i should check next....

dstinson
07-22-09, 12:32 AM
not that this is by anyway the correct way to fix this problem, but I put a switch under my dash (by my feet) so I could trouble shoot my 'service air ride' message. I can jump the relay so I knew I could put a switch from the relay (actually only 1 wire) and then grounded it. I get the error when I start the truck and as soon as I flip the switch for about 5 seconds it goes away. I assume the sensors are working because the error does go away after I inflate the shocks, just not sure why it does not do it automatically. Maybe you guys will find something I over looked, keep up the posts!

sk7
07-22-09, 01:29 AM
Good tip dstinson, I'll give that a try. Starting the truck I get no response from the compressor. No service anything light either. Only after driving a few feet does the service stability system light kicks in. I don't know if a major fault in the stabilitrac system can disable the auto leveling suspension? I finally found a seller willing to ship to Canada on ebay (innova 3150), so that might help fixing the problem. I will post the diagram for the colors of the relay tomorrow. I recall it was different for the EXT, but application is the same. +12V from #1 fusebox, +12V out to compressor, switched ignition, and trigger from SCM. Do you get a negative signal from the module on the other wire after turning on ignition?

luxurylife33
07-22-09, 01:36 AM
didnt try that, will try tomorrow if i get a chance...

coralreef35mm
07-22-09, 09:13 AM
There is a $10 kit kit available to use to pump up your shocks until you get the automation working..It works good

sk7
07-22-09, 04:39 PM
Here is a pic of the SCM location:

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade118.jpg

And the module itself...

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade119.jpg

I will give this manual bypass of the compressor upon startup a try.

sk7
07-22-09, 04:58 PM
Wiring diagram for luxurylife33:


http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/CAZRR7DGCAAIP89ACACL7JOCCA9K9I5SCAY.gif

Hope this can help!

dstinson
07-22-09, 05:08 PM
you wouldn’t happen to have one (diagram) for the ride height sensors do you? I want to know what the sensors should read for resistance (i.e. the range) thanks. This is getting to become a good in-depth thread

sk7
07-22-09, 05:27 PM
Here you go...

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/WD2.gif


Since all troubleshooting is done with the tech 2 scanner, its a bit of a pita to diagnose anything without. As far as I can see, ref 5V is used for level signal, so lower voltage means lower height or the other way around.

All level info is on connector C3 on the SCM, the lower one. Here is info.

Suspension Control Module - C3



Connector Part Information
121102206
24-Way F Micro-Pack (LT BLU)

Pin
Wire Color
Circuit No.
Function

A1
PNK/WHT
1101
Damping Lift/Dive Signal

A2
TAN/WHT
1207
Left Front Suspension Position Sensor Signal

A3
PPL/WHT
1205
Left Front Suspension Position Sensor Voltage Reference

A4
TAN/WHT
1213
Right Front Suspension Position Sensor Signal

A5
LT GRN/

WHT
1210
Left Rear Suspension Position Sensor Signal

A6
RED/BLK
1208
Left Rear Suspension Position Sensor Voltage Reference

A7
LT GRN/

WHT
1216
Right Rear Suspension Position Sensor Signal

A8
LT BLU
1059
Steering Wheel Position Sensor Signal

A9
GRY
705
5 Volt Reference

A10
DK GRN/

WHT
817
Vehicle Speed Signal

A11
--
--
Not Used

A12
DK BLU/

WHT
1114
Left Rear Suspension Damper Solenoid Control

B1
BRN
541
Ignition 3 Voltage

B2
LT BLU/

BLK
1206
Left Front Suspension Position Sensor Low Reference

B3
PPL/WHT
1211
Right Front Suspension Position Sensor Voltage Reference

B4
LT BLU/

BLK
1212
Right Front Suspension Position Sensor Low Reference

B5
LT GRN/

BLK
1209
Left Rear Suspension Position Sensor Low Reference

B6
RED/BLK
1214
Right Rear Suspension Position Sensor Voltage Reference

B7
LT GRN/

BLK
1215
Right Rear Suspension Position Sensor Low Reference

B8
ORN/BLK
556
Low Reference

B9
ORN/BLK
1057
Low Reference

B10
--
--
Not Used

B11
TAN
2252
Leveling Pressure Sensor Signal

B12
--
--
Not Used


I wasnt able to copy exactly the info from the manual, its too long or ?

dstinson
07-22-09, 07:31 PM
wow, this is good stuff, thank you very much (although I don't have a tech 2 scanner). Now are you replacing your SCM with a new one? I am curious to see if this will fix your problem. Perhaps the SCM is not telling the pump to activate?? Keep up the good work.

sk7
07-22-09, 08:59 PM
I don't have the nerve to ask the stealership how much that little box is worth! After having to pay $6 each for the 2 rubber bump stops for the fuel door (now I know where breast implants are manufactured!), and 90$ each for the cover over the lighter plugs on the center console, I'm affraid this will mean remortgage the house! Also replacement module must first be recalibrated to the truck upon installation, with, you guessed it, tech 2 scanner.

After getting up from my nite shift, with brain still in limp mode, I figured maybe I was looking for a fault in the system that isn`t there? What if the compressor doesnt come on because the truck is level? It does look ok to me afterall, and I dont really have a reference point as to what the proper level should be. So I unplugged one of the hose from the rear shocks, hoping for some pressure in, nada! I will install a switch inside triggering neg on the factory relay, + a red led to signal when the compressor is runnning, while I wait for my OBD scanner to arrive...

Making the compressor run for about 30 seconds does bring up the rear quite a bit! Will keep progress posted. I'm also interested in checking out if the 4 level sensors are operational, will get to that next week.

luxurylife33
07-22-09, 09:53 PM
SK7, thanks!

Believe it or not the message went away this morning and the compressor kicked on, on its own! I would still like to find the problem, but I dont know how I'm going to scan a code that isn't there.... I wonder if the SCM stores codes like the main ECU does.......

dstinson
07-22-09, 10:22 PM
I never asked but sk7, is your truck lowered? Mine is lowered (spindles) and it sits pretty even when the bags are deflated, however, when I manually fill the bags with air the back end prob raises about 1/2 inch. Not noticeable but I think it rides better with air and also I tow a trailer so I need that back end up. On another note, I took off the wheels and played with the sensors (adjusting the height, by taking the rod off) to see if I could get it to throw a code and never could. I was thinking about seeing if a neighbor of mine would just unplug his SCM and plug it in my truck to see if that would make a difference but you say they need to be calibrated for our specific trucks with the dealer tool? I am not about to go buy one if I can’t determine that is the problem.

sk7
07-22-09, 11:46 PM
Luxurylife: Great news! But I do hate it when problems just fix themselves without knowing why, you just know its gonna go wrong again... someday. Hope it stays stays runnning like it should. Saves $$$.

Dstinson: Truck is stock, no mods done to suspension or wheels. GM SI manual is not too clear about the module recalibration, it does need to be done for a new unit, but they don't specify for troubleshooting purposes. I figured I can't be worse than unplugging the battery, so I unpluged mine and opened up the module to see if anything was "wrong" on the inside. My truck sat outside for a few months without a sunroof or side window (salvage title), so it was kinda wet when I got it (actually frozen since it was middle of winter). But no harm done to electronics. If you have a buddy with a similar model, I would go ahead swap the SCM to see if it changes anything. Just unplug the power plug (top one) first and replug last, to be on the safe side.

sk7
07-24-09, 05:37 AM
I installed a manual overide switch on the dashboard activating the factory compressor relay + a red led to come when compressor is running so I can do the happy dance if the system finally decides to work by itself! Ride sure improves with air in the shocks! Going camping this weekend, this will be the first tow I do with this truck (small tent trailer), I'll see how things turn out with my temporary setup. Will keep you posted on monday.

dstinson
07-24-09, 02:33 PM
The led was a good idea, never thought about that one. I am going camping too so I put the 18's back on, will pump them full of air for the ride. I would be curious to know on a truck that has air ride working without towing trailer or crap in the back, how much air is actually in the shocks. It's kinda cool to have an over ride switch, especially with the trailer so I can manually add more if need be. Keep us posted if you ever get a resolution.

sk7
07-28-09, 12:18 PM
I am also wondering how much air pressure is in the system at proper height. I will get a guage on the system, just for reference. The automated system didnt work at all on its own during the weekend trip. Seems like I had to add a bit of air to raise the back every 30 minutes or so. Tent trailer is fairly light, 2500lbs apprx. I once got a limited stabilitrack message upon starting the engine after pumping a bit too much manually! I'm gonna try a test of the height sensors (min-max output) this week. Will keep posted.

luxurylife33
07-28-09, 10:52 PM
well the message is back..... grrrrrrrrrrrrrrrrrrrrrrrrrrrrr ..... would this have anything to do with adding 2009 OEM 22" rims? message came on about a week after i installed them

sk7
07-29-09, 09:08 AM
What is the message you are getting? I found a few explanations about the different suspension-ABS related service messages in the SI manual. Will post em here later tonight. Somehow the auto leveling suspension and stabilitrac is not connected together (I may be wrong here). So my air compressor is non op and I'm not getting any codes. The stabilitrac is also non-op and I do get a code for that one. Reading previous posts on the forums seems to point to defective front ABS sensors (there was apparently a recall on that), or steering shaft input sensor. I'd like to get the auto level suspension working first, then move on to the stabilitrack.

luxurylife33
07-29-09, 12:57 PM
i cannot bring it to my brothers shop until 2 weeks.... hes on vacation ..... i dont wanna spend $200+ for the dealer to scan it... so until then I do not know the code....but the message is saying "service ride control" .... its been working on and off the past two weeks, im thinking something is loose or on its way out

sk7
07-29-09, 02:12 PM
Same here! Dealer is begging me to bring the truck in for a quick checkup. :suspense: Yeah right, I just wish they would rent that Tech 2 scanner instead. On the regular escalade there's a huge connector underneath the truck, right behind the rear right wheel. All the signals for the SCM and rear AC unit go thru there. Mine was in pretty bad shape, I suspected my problems were due to a broken wire from this connector. I cleaned and checked and all is well there. Maybe the EXT has a similar connector somewhere? One cheap test would be to manually activate the factory relay, ground the light blue while ignition on, see if the compressor is working.

sk7
08-03-09, 08:39 PM
Got my Innova 3150 scanner today, Wow 7 ABS codes in memory, pretty much all covering the stability system! Basically everything is not working properly or ? I got misfire cyl 8 - knock sensor issues that I want to adress before resolving suspension abs stuff. Will keep troubleshooting after I can get the engine to work properly.

luxurylife33
08-03-09, 09:27 PM
I already did the relay trick, the compressor is fine.... but i dont wanna hook it up ghetto style to a switch, i want it fixed. Not to mention there no way of knowing when to stop pumping air into the shocks...

sk7
08-03-09, 09:51 PM
Same here, its always a guessing game... I tried the switch hoping it would 'wake up' the system to work automatically. No codes I got are related to the auto leveling ride. Worst case scenario I'm gonna make my own auto ride module lol! All the required signals are there in the back, I'll just need a reference as to what the proper ''level'' height is, and take it from there! Huuummm another winter project...

luxurylife33
08-03-09, 11:19 PM
that should be real interesting... mine stills works whenever it feels like it. by next monday I should have the car at my brothers shop to get it scanned with his snap-on modis... hopefully its something stupid

luxurylife33
08-12-09, 10:01 PM
my brothers $10,000 modis snap on scanner doesn't read scm codes .... blaaaaaa .....guess im bringing it to the dealer so they can scan it for $125 unless anyone else has a better suggestion.........

luxurylife33
08-12-09, 10:13 PM
are you sure the Innova 3150 scanner scans scm codes? i know you said you got ABS codes.... my brother claims no $150 scanner will pick up scm codes .... he said any "CAN" will pick up ABS codes though ..... just wanna know before i drop $150 on this scanner

sk7
08-12-09, 10:20 PM
You are correct the 3150 will read ABS and engine related DTC. I got a bunch (7) when I first checked the ABS (stabilitrack), now I only get C0265. I get no service air ride system message, even tho the system is not functionning. There is a section on the scanner for enhanced trouble codes, I get nothing when I go there. Whats the specific code for the auto leveling suspension? I can have a look if its included in the equus website.

luxurylife33
08-12-09, 10:35 PM
i have no clue.... my brother is ASE master certified and claims the dealer is my only hope at reading these codes :(

BTW, i had 7 unrelated BCM stored codes that were all bogus except for one.... one of my cluster lights is out. Those are all deleted (except the cluster light one wouldn't delete, gotta fix that). No engine or ABS codes for me.

sk7
08-12-09, 10:52 PM
Only 3 trouble codes related to the auto leveling suspension according to service manual, here is a listing and diagnostic procedure.



DTC C0655
Circuit Description
The vehicle's rear leveling compressor motor is switched on and off via a compressor motor relay which is controlled by the Suspension Control module. The Suspension Control module provides a switched path to ground whenever compressor activity is required. The Suspension Control module continually monitors the compressor motor relay circuitry to determine if the voltage level agrees with the commanded state.

Conditions for Running the DTC
Whenever the compressor is activated.

Conditions for Setting the DTC
Open in the control circuit of the compressor motor relay.
Short to ground in the control circuit of the compressor motor relay.
Short to battery in the control circuit of the compressor motor relay.
Open in the ignition 3 voltage circuit of the compressor motor relay.
Open IGN 3 fuse.
A malfunctioning compressor motor relay.
Action Taken When the DTC Sets
The compressor motor relay is disabled for the remainder of the ignition cycle.
Stores a DTC C0655 in the Suspension Control module memory.
Conditions for Clearing the DTC
The Suspension Control module no longer detects a open, short to ground, or a short to battery in the control circuit of the compressor motor relay.
Using a scan tool.
A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
Diagnostic Aids

Important
A leak in the air tube between the rear shocks and compressor will cause excessive running of the compressor motor. After approximately 5 minutes of continuous running without a change in body-to-wheel height or system pressure, the Suspension Control module will command the compressor motor relay to the off state for the remainder of the ignition cycle.


The following conditions may cause a malfunction to occur in the compressor motor relay:

A short to ground in the control circuit.
An open in the control circuit.
A short to battery in the control circuit.
An open in the ignition 3 voltage circuit.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Command both the ON and OFF states. Repeat the commands as necessary.

Tests the coil of the relay for continuity.

Tests for voltage at the coil side of the compressor motor relay. The IGN 3 fuse supplies power to the coil side of the compressor motor relay.

Verifies that the Suspension Control module is providing ground to the compressor motor relay.

Tests if ground is constantly being applied to the compressor motor relay.

Test for a short to voltage or an open in the control circuit of the compressor motor relay.

The replacement Suspension Control module must be calibrated.

Step
Action
Value(s)
Yes
No

Schematic Reference: Automatic Level Control Suspension Schematics

1
Did you perform the Automatic Level control Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check - Automatic Level Control

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, command the compressor ON and OFF.
Does the compressor turn ON and OFF with each command?
--
Go to Diagnostic Aids
Go to Step 3

3
Turn OFF the ignition.
Disconnect the compressor motor relay.
Measure the resistance of the relay coil.
Does the resistance measure within the specified value?
30-90 ohms
Go to Step 4
Go to Step 12

4
Turn ON the ignition, with the engine OFF.
Probe the coil side feed circuit of the compressor motor relay with a test lamp that is connected to a good ground. Refer to Circuit Testing in Wiring Systems.
Does the test lamp illuminate?
--
Go to Step 5
Go to Step 11

5
Connect a test lamp between the control circuit of the compressor motor relay and the coil side feed circuit of the compressor motor relay. Refer to Circuit Testing in Wiring Systems.
With a scan tool, command the compressor ON and OFF .
Does the test lamp turn ON and OFF with each command?
--
Go to Step 9
Go to Step 6

6
Does the test lamp remain illuminated with each command?
--
Go to Step 8
Go to Step 7

7
Test the control circuit of the compressor motor relay for a short to voltage and an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 10

8
Test the control circuit of the compressor motor relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 10

9
Inspect for poor connections at the compressor motor relay. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 12

10
Inspect for poor connections at the harness connector of the Suspension Control module. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 13

11
Repair the coil side feed circuit of the compressor motor relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
--
Go to Step 14
--

12
Replace the compressor motor relay.

Did you complete the replacement?
--
Go to Step 14
--

13

Important
After replacement, use the scan tool to perform the calibration procedure for the Suspension Control module, located under Special Functions: Recalibration.


Replace the Suspension Control module. Refer to Electronic Suspension Control Module Replacement .

Did you complete the replacement?
--
Go to Step 14
--

14
Use the scan tool in order to clear the DTCs .
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK


DTC C0660
Circuit Description
The exhaust solenoid valve is switched on and off via the Suspension Control module. The Suspension Control module provides a switched path to ground whenever exhaust activity is required and during a compressor "head-relief" sequence which occurs at compressor start-up if system pressure is lower than 68.95 kPa (10 psi). The Suspension Control module continually monitors the exhaust solenoid valve circuitry to determine if the voltage level agrees with the commanded state.

Conditions for Running the DTC
Whenever the exhaust solenoid valve is activated.

Conditions for Setting the DTC
An open in the control circuit of the exhaust solenoid valve.
A short to ground in the control circuit of the exhaust solenoid valve.
A short to battery in the control circuit of the exhaust solenoid valve.
An open in the battery positive voltage circuit of the exhaust solenoid valve.
An open RTD fuse.
A malfunctioning exhaust solenoid valve.
Action Taken When the DTC Sets
The exhaust solenoid valve is disabled for the remainder of the ignition cycle.
Stores a DTC C0660 in the Suspension Control module memory.
Conditions for Clearing the DTC
The Suspension Control module no longer detects a open, short to ground, or a short to battery in the control circuit of the exhaust solenoid valve.
Using a scan tool.
A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
Diagnostic Aids
The following conditions may cause a malfunction to occur in the exhaust solenoid valve:

A short to ground in the control circuit.
An open in the control circuit.
A short to battery in the control circuit.
An open in the battery positive voltage circuit.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Command both the ON and OFF states. Repeat the commands as necessary.

Test the exhaust solenoid valve resistance.

Tests for voltage at the coil side of the exhaust solenoid valve. The RTD fuse supplies power to the coil side of the exhaust solenoid valve.

Verifies that the Suspension Control module is providing ground to the exhaust solenoid valve.

Tests if ground is constantly being applied to the exhaust solenoid valve.

Test the control circuit of the exhaust solenoid valve for a short to voltage and an open.

The replacement Suspension Control module must be calibrated.

Step
Action
Value(s)
Yes
No

Schematic Reference: Automatic Level Control Suspension Schematics

1
Did you perform the Automatic Level Control Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check - Automatic Level Control

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, command the exhaust ON and OFF.
Does the exhaust solenoid valve turn ON and OFF with each command?
--
Go to Diagnostic Aids
Go to Step 3

3
Turn OFF the ignition.
Disconnect the compressor leveling module connector.
Measure the resistance from the positive battery voltage circuit of the exhaust solenoid valve and the control circuit of the exhaust solenoid valve.
Does the resistance measure within the specified value?
30-90 ohms
Go to Step 4
Go to Step 12

4
Turn ON the ignition, with the engine OFF.
Probe the positive battery voltage circuit of the exhaust solenoid valve with a test lamp that is connected to a good ground. Refer to Circuit Testing in Wiring Systems.
Does the test lamp illuminate?
--
Go to Step 5
Go to Step 11

5
Connect a test lamp between the control circuit of the exhaust solenoid valve and the positive battery voltage circuit of the exhaust solenoid valve, harness side. Refer to Circuit Testing in Wiring Systems.
With a scan tool, command the exhaust ON and OFF .
Does the test lamp turn ON and OFF with each command?
--
Go to Step 9
Go to Step 6

6
Does the test lamp remain illuminated with each command?
--
Go to Step 8
Go to Step 7

7
Test the control circuit of the exhaust solenoid valve for a short to voltage and an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 10

8
Test the control circuit of the exhaust solenoid valve for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 10

9
Inspect for poor connections at the exhaust solenoid valve. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 12

10
Inspect for poor connections at the harness connector of the ESC module. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 13

11
Repair the positive battery voltage circuit of the exhaust solenoid valve. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
--
Go to Step 14
--

12
Replace the exhaust solenoid valve.

Did you complete the replacement?
--
Go to Step 14
--

13

Important
After replacement, use the scan tool to perform the calibration procedure for the Suspension Control module, located under Special Functions: Recalibration.


Replace the Suspension Control module. Refer to Electronic Suspension Control Module Replacement .

Did you complete the replacement?
--
Go to Step 14
--

14
Use the scan tool in order to clear the DTCs .
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK


Text too long, part 2 coming up....

sk7
08-12-09, 10:53 PM
DTC C0711
Circuit Description
The suspension control module uses a 5 volt analog air pressure sensor to determine the amount of air pressure in the Automatic Level Control (ALC ) system. The valid signal voltage range of the sensor is 0.15-4.85 volts. The sensor signal voltage will increase and decrease within the valid voltage range as system pressure increases and decreases.

Conditions for Running the DTC
The Ignition is ON.

Conditions for Setting the DTC
The air pressure sensor's signal voltage is out of the valid range.
A short to ground, short to voltage, or an open in the pressure sensor, or the circuits to the sensor.
Action Taken When the DTC Sets
DTC C0711 is stored in memory.
ALC system pressure is set to a default value.
The ALC system is disabled.
Conditions for Clearing the DTC
A current DTC will clear when the malfunction is no longer present.
A history DTC will clear after 100 malfunction free ignition cycles.
Using a scan tool.
Diagnostic Aids
If DTC C0870 is present, perform the diagnosis for that DTC first.

The following conditions may cause a malfunction to occur:

An open in the 5 volt reference circuit of the air pressure sensor.
A short to ground in the 5 volt reference circuit of the air pressure sensor.
An open in the signal circuit of the air pressure sensor.
A short to ground in the signal circuit of the air pressure sensor.
An open in the low reference circuit of the air pressure sensor.
A malfunction in the air pressure sensor.
A leak in the air tube at the air pressure sensor may cause a faulty sensor voltage reading.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Tests for a high resistance or an open in the ground circuit.

Check for open or high resistance in the sensor ground circuit.

The replacement suspension control module must be calibrated.

Step
Action
Value(s)
Yes
No

Schematic Reference:

1

Important
If DTC C0870 is present, perform the diagnosis for DTC C0870 first.


Did you perform the Automatic Level Control Diagnostic System Check?
--
Go to Step 2
Go to

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Air Pressure Sensor data parameter in the ALC data list.
Does the scan tool indicate that the Air Pressure Sensor parameter is within the specified range?
0.15 -- 4.85 V
Go to in Wiring Systems.
Go to Step 3

3
Turn OFF the ignition.
Disconnect the ALC compressor connector.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the air pressure sensor data parameter.
Does the scan tool indicate that the air pressure sensor data parameter is at the specified value?
0.0 V
Go to Step 4
Go to Step 6

4
Connect a 3 amp fused jumper wire between the 5 volt reference and signal circuit of the ALC compressor harness connector.

Does the scan tool indicate that the Air Pressure Sensor data parameter is within the specified range?
4.8-5.2 V
Go to Step 9
Go to Step 5

5
Test the pressure sensor signal circuit for an open, or short to ground. Refer to and in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 6

6
Test the pressure sensor signal circuit for a short to voltage. Refer to and in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 7

7
Test the pressure sensor 5 volt reference circuit an open, or short to ground. Refer to and in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 8

8
Test the pressure sensor 5 volt reference circuit for a short to voltage. Refer to and in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 10

9
Test the pressure sensor low reference circuit for an open, or short to voltage.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 12

10
Inspect for poor connections at the ALC compressor harness connector. Refer to and in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 11

11
Inspect for poor connections at the suspension control module harness connector. Refer to and in Wiring Systems.

Did you find and correct the condition?
Go to Step 14
Go to Step 13

12
Replace the pressure sensor. Refer to in Automatic Level Control.

Did you complete the replacement?
Go to Step 14
--

13

Important
After replacement, use the scan tool to perform the calibration procedure for the suspension control module, located under Special Functions: Recalibration.


Replace the suspension control module. Refer to in Electronic Suspension Control (ESC).

Did you complete the replacement?
--
Go to Step 14
--

14
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK

I'm gonna have a look at the innova website to see if those codes are supported by the 3150-3160.

Edit: C0655 and C0660 are listed on their website. But not C0711. I'm not sure that means these codes can be checked with their scanner. Too bad you don't live a bit closer, I would have been an easy check to do once the service air ride message pops up.

luxurylife33
08-12-09, 11:08 PM
thanks! i will have to try it all one day..... i dont think its worth $125 for the posibility of the 3 codes, ill check all that!

now when it sez......

go to step 3
go to step 12

step 3 answers yes or no to the question?

sk7
08-12-09, 11:25 PM
I wish I could cutNpaste the info as it appears in the manual, its a lot easier to understand. Pics also do not work with this function... Which DTC are you looking at?

luxurylife33
08-13-09, 03:34 AM
i understand.... is the top yes or no?

theres "go to step" listed twice... which one is yes and which one is no? or are they in all diffrent orders? im gunna buy the dvd i think!

sk7
08-13-09, 11:21 AM
Do you have access to a fax? I can send those out to you saturday morning from work. Just PM me the number. I can also include the plug layout so troubleshooting will be a breeze. But I do recommended that DVD service manual from blownc5, its great!

pcguy760
08-15-09, 05:31 AM
Not tryin to threadjack or anything, but Sk7, is that service manual from blownc5 something like the AllData service manual on a PC?

sk7
08-15-09, 08:18 AM
Its the factory GM Service Information Manual on DVD. Covers from 1998-2005 GM products. Its a must have!

luxurylife33
08-15-09, 12:44 PM
Damn, I only have access to a fax mon-fri..... I will contact blownc5 for that dvd.... it was 15$ ?

sk7
08-15-09, 02:48 PM
Yep that's the one. I paid a bit more than that a few months ago...

luxurylife33
08-15-09, 11:51 PM
My birthday's on the 19th, if anyone wants to get me something nice.....

http://www.etoolcart.com/browseproducts/Scanner-Tech-2----OTC3628.HTML

pcguy760
08-16-09, 04:19 AM
My birthday's on the 19th, if anyone wants to get me something nice.....

http://www.etoolcart.com/browseproducts/Scanner-Tech-2----OTC3628.HTML

Hey I would on the conditions that you were...

1. a supermodel female
2. clean my rides and my garage
3. make sure I was tuned everyday and my piston was firing at optimum in all your cylinders


HAHA cracks myself up sometimes lol.

:)

sk7
08-17-09, 11:04 AM
I would want to see pics of the supermodel B4 sending in the cash!!!! I searched a bit for a PC based or palm or ? emulator program of GM Tech 2 with no luck. There was on Fleaybay a TIS software, which is in the GM manual for operating the tech 2, but from my understanding the TIS software alone won't communicate to vehicule without the tech 2 device. I find this a pita having VAGcom for VW on my laptop, and being able to duplicate pretty much anything the dealer can do, but there's nothing for GMs?

luxurylife33
09-05-09, 12:11 PM
sk7, my manual/dvd they sent did not work! :( can you tell me what the voltages should be for the front sensors and the steering wheel position sensor? I got the colors of the wires for them in an earlier post, I just need to know their allowed voltage readings....

As you can tell, Im really getting into this! Replaced the front shocks, nothing! replaced the relay, nothing! replaced the rear shocks, you guessed it, nothing! The rear height sensors are within range, just want to check the steering wheel position sensor voltage and front height sensors with the multimeter. Im running out of ideas...

sk7
09-05-09, 02:56 PM
I also had issues with the install of the SI DVD, you really need to follow all the instructions. I didnt remove the java program at first, that caused an issue. There was also sumthin else that related to microsoft .net framework and windows XP family edition. I the end I finally managed to make it work, took a bit of time and reading.

As for the SCM, I'm not sure exactly the interaction for the stabilitrack, ECBM and sensors. I'll focus my attention on getting the air ride compressor to work on its own first. I also got new shocks in the back. I can fax you those sheets late monday nite (working nites monday-tuesday this week.) Did you keep the Bilsteins? I was curious how that bypass of the solenoid control in the OEM shock works? Is it just a resistance value put in between the 2 wires?

Since there's a few of us with air compressor issues, I'm pretty confident we can sort this out together.

luxurylife33
09-05-09, 06:16 PM
Yea i still have the bilsteins. Im pretty confident those are not to blame. The original shocks werent leaking terribly and the compressor wouldnt turn on then. I am goin to try this dvd one more time and if its busted ill pm u the fax. Thanks

sk7
09-05-09, 08:02 PM
I agree the bilsteins are not to blame, I was just curious on what the bypass was to fool the SCM module to work. Good luck on the DVD install, you can pm me for help or email blownC5, he was a good help also to resolve install issues.

luxurylife33
09-05-09, 11:02 PM
I ended up buying the DVD off ebay... the guy has been pretty helpful, but to no avail ... he did offer a full refund, but Im going to have my brother try it on his comp...

And yeah the bilsteins come with a black box that supposably bypasses the "autoride" sensor. According to arnott, GM installed the sensor to keep aftermarket companies from making the shocks.... So far he said only the Bilsteins had made a bypass feature.

luxurylife33
09-06-09, 12:52 PM
does the manual give a voltage reading range for the steering wheel position sensor?

thanks for all your help! ive put about $1000 into this problem and still not solved.... :(

luxurylife33
09-06-09, 03:05 PM
Also if you could get me the voltage range for the "Leveling Pressure Sensor" that would be great!

luxurylife33
09-06-09, 03:37 PM
front right signal - 2.70v
front left signal - 2.83v
level pressure sensor signal - .41v
steering position sensor signal - 10.9v or 13.6v ... theres 2 light blue wires, dont know which is which
left rear signal - 2.78v
right rear signal - 2.68v
"ignition 3" voltage - .41v (seems low)
Damping Lift/Dive Signal - 13.31v

these are my readings

sk7
09-06-09, 08:31 PM
I didn't get into much details when I was looking at the SCM a few weeks ago. The 5 volts ref (gray A9) was ok, A10 lt blue wire trigger negative to the compressor relay works (activates the compressor once it put to ground). Power (org) and ground was present at the GRY Metri-Pack connector. Ignition 3 (brown) should be higher than 12 volts (either at the Lt blu 24 way Micro pack connector) or at the compressor control relay. So that might be something to look at for starters. I hope your truck has enough miles to justify replacing the shocks. I should post pics of the one I removed from the back, they were shot!!!

I'll need to dig a little further for those reference voltage for the suspension level, solenoid and steering input. You are still getting no error messages and compressor isnt working? I need to get a car outta the shop before tomorrow, will get back to you with the info before Zzzz time.

luxurylife33
09-07-09, 01:32 AM
almost at 88k miles.... the rears were SHOT.... the fronts were in good shape so ill just sell em on ebay and try and get some money back, rather have new ones anyways, i plan on keeping the car for a while

sk7
09-07-09, 11:01 AM
Here's what I could find in the service manual:

-Shocks solenoid reference value should be 1.5 - 3.3 Ohms. Didnt say if that would vary with shock fully extended or ? I don't think it would matter.

-The suspension level indicators are voltage driven, 0.5 - 4.5 Volts signal at the SCM. Disconnected should read 0.5 at the SCM, jumping the 5V ref to to signal circuit should show 4.5V at SCM.

-Steering wheel input reference is 0.35 - 4.75 volts. It has 2 separate outputs. That sensor is listed in the stabilitrac section tho, so it should not be an issue with the suspension control stuff.

sk7
09-07-09, 11:09 AM
Wiring diagram to troubleshoot that IGN 3 input issue...

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/SCM.gif

luxurylife33
09-07-09, 11:45 AM
"-Steering wheel input reference is 0.35 - 4.75 volts. It has 2 separate outputs. That sensor is listed in the stabilitrac section tho, so it should not be an issue with the suspension control stuff."

This may be the problem, your right about the two outputs, they are reading 10.9 and 13.6v at the SCM ...... nowhere near the range they should be... and i have seen plenty of threads with people's steering position sensor going bad, but the said they have a "service stability system" issue and not a "service ride control" issue .... how much is the sensor? if its cheap its worth a shot .... ill have to call the stealership tomorrow....

edit: btw i appreciate all the help!

ESKY02
09-07-09, 04:27 PM
K i found the relay, hooked to the front side of my fuse box. The number on it is 1219603. I pulled the relay off, and jumped the red to red wire. All i got was a spark and a click thats it. Now i jump them and get nothing. The "stud 1" fuse is good and the "ign 3" fuse is good. am i doing something wrong?

sk7
09-07-09, 04:49 PM
Jumping the 2 bigger guage wires should get the compressor to run. If not its either not getting power (there's a plug on it) or its shot. You can easily remove it, its a few 13mm nuts to take off. You can then try it on the bench with a spare battery.

I agree those steering input sensors are prone to failure, but it shouldnt mess with the suspension control module. If you get no service stability system message, let's assume all is well there. Did you manage to get 12V at the ignition 3 wire? That would explain why you get no error message, technically the SCM doesn't power up, no compressor activation, no error message either?

luxurylife33
09-07-09, 05:25 PM
I have had a "service ride control" message since the problem began.

On a good note, I fix customers cars for a local car wash (paintless dent/ scratch removal) and he's good friends with a service manager (they use the car wash for all their cars) at a Chevy dealership and says he'll speak to him about my issue and most likely scan it for nothing! :)

luxurylife33
09-07-09, 06:08 PM
I confused tan and brown ... the ign 3 is fine.... the tan i get about .3v when its dumped and if i fill it, i get 1.5v .... is that OK for the leveling pressure sensor voltage range? 1.5v is kind of low still for the sensor, where as the others go up to about 5v, but i could be wrong....

luxurylife33
09-07-09, 06:16 PM
From your previous post:

Does the scan tool indicate that the Air Pressure Sensor data parameter is within the specified range?
4.8-5.2 V

hmmmmmm maybe that sensor is bad..... mine read .3 dumped and 1.5 filled

ESKY02
09-07-09, 08:26 PM
SK7,
I unplugged the relay to jump the red wires. As soon as i touched the jumper wire from red to red i got a spark and a click thats it. Second time i got nothing. Now what? I had the key to the on position if that makes a difference.

sk7
09-07-09, 08:29 PM
Air pressure sensor data? Is that the exhaust solenoid on the compressor? I admit I didnt test that one either!

ESKY02 - I answered your question a few posts up, If the compressor is short to ground (motor) the big fuse must be shot in the fusebox (after the jump attempt), its the first one on the right if I remember correctly... No need to leave the key in the on position for the test.

ESKY02
09-07-09, 08:32 PM
wow whos talking to who? im lost hahaha

sk7
09-07-09, 08:37 PM
No prob! Do you have a test light? Check to make sure the power wire still has 12V. The compressor does take quite a bit of juice to kick on (not as much as the ECBM motor mind you!). Maybe it was just stiff from not being used. I would replace the fuse (if it is blown) and retry by just touching the contacts together for a split second, see if you can get it to run. If not you will need to remove it for further investigation or replacement.

ESKY02
09-07-09, 08:39 PM
What fuse is it?

sk7
09-07-09, 09:05 PM
Power to the air compressor relay is from one of those MAXI fuses in the fuse-relay box under hood. #1 or 2 but don't quote me on that one... Easy to find which one is shot with your test light.

ESKY02
09-07-09, 09:11 PM
Checked them all they are all good. Im stuck. I dont understand why i dont get a spark or click now.

sk7
09-07-09, 09:14 PM
The compressor is most likely shot. You can leave the jumper in the relay socket and check if you have power at the round plug right beside the compressor. If you do plan on removing the compressor and replace it.

ESKY02
09-07-09, 09:19 PM
So if i dont have power then the compressor is shot? Its fine if it is i have a new one ready to go in.

luxurylife33
09-07-09, 09:53 PM
just remove the compressor and hardwire it.... looks like a fairly simple removal

ESKY02
09-08-09, 04:34 PM
my truck doesnt sag. it sits level. I hooked my tandem trailer to it to get it to sag and still nothing. When i unhooked the trailer it came back to the level postion. Any thoughts on that?

luxurylife33
09-08-09, 08:54 PM
it has to be sagging, its really not easy to see it, but if you measure it, you'd be surprised. When my shocks are manually filled with air, it sits 3.5" higher than when I hook up my trailer with no air.

Manually pump air via the relay jumper take some measurements from the tow hitch to the ground. Drive around for a little bit to get rid of some air and then hook the trailer up and measure agin.... you'll notice a big change. Its hard to see by eye.

WSLN 6
09-09-09, 03:45 AM
Any more progress? I have the exact same problem with my ESV as does my buddy with his Denali. We swapped SCM's, but that didn't help. Probing the light blue wire at the SCM will activate the compressor, but that's as far as we got so far.

sk7
09-09-09, 04:57 AM
Good to know! I don't have access to another SCM for that test. I'm gonna look into this tonight, no check engine light on for the last week, time to move on to another issue... Good idea to measure from the hitch receiver to the ground! I also didnt notice the sagging from the back end till I started reading the forums here and realizing the air compressor is supposed to raised the back end automatically.

sk7
09-09-09, 11:26 PM
Had a few hours of free time to finally have a look at the SCM today, here's the data I collected:

Connector Part Information
12110626
8-Way F Metri-Pack 280 Series (GRY)

Pin
Wire Color
Circuit No.
Function

A
LT BLU/WHT
1116
Right Front Suspension Damper Solenoid Control (1.9 Volts)

B
DK GRN
1119
Right Rear Suspension Damper Solenoid Low Reference (0 Volts)

C
BLK
1450
Ground OK

D
ORN
2440
Battery Positive VoltageOK

E
BLK
1450
GroundOK

F
GRY
1113
Left Front Suspension Damper Solenoid Low Reference(0 Volts)

G
GRY
1117
Right Front Suspension Damper Solenoid Low Reference(0 Volts)

H
DK GRN
1115
Left Rear Suspension Damper Solenoid Low Reference(0 Volts)

Suspension Control Module - C2

Connector Part Information
12110244
24-Way F Micro-Pack (PNK)

Pin
Wire Color
Circuit No.
Function

A1
--
--
Not Used

A2
WHT
790
PWM Serial Data - w/VSES

--
--
Not Used - w/o VSES

A3
GRY
791
PWM Serial Data - w/VSES

--
--
Not Used - w/o VSES

A4-A6
--
--
Not Used

A7
WHT
1294
Variable Effort Steering Actuator Supply Voltage6.8mV

A8
BRN
1295
Variable Effort Steering Actuator Control6.8mV

A9
GRY
416
5 Volt ReferenceOK

A10
LT BLU
2248
Real Time Damping Compressor Relay ControlSTARTS COMPRESSOR WHEN GROUNDED

A11
--
--
Not Used

A12
LT BLU/

WHT
1107
Left Front Suspension Damper Solenoid Control1.7mV

B1
DK BLU/

WHT
1118
Right Rear Suspension Damper Solenoid Control1.5mV

B2-B4
--
--
Not Used

B5
DK BLU
2249
Real Time Damping Compressor Exhaust Control26mV

B6-B7
--
--
Not Used

B8
DK BLU/

WHT
1126
SCM Class 2 Serial Data

B9
--
--
Not Used

B10
BLK
407
Low Reference6.8mV

B11-B12
--
--
Not Used

Connector Part Information
121102206
24-Way F Micro-Pack

Pin
Wire Color
Circuit No.
Function

A1
PNK/WHT
1101
Damping Lift/Dive Signal11.40V

A2
TAN/WHT
1207
Left Front Suspension Position Sensor Signal2.71v

A3
PPL/WHT
1205
Left Front Suspension Position Sensor Voltage Reference4.98V

A4
TAN/WHT
1213
Right Front Suspension Position Sensor Signal2.56V

A5
LT GRN/

WHT
1210
Left Rear Suspension Position Sensor Signal1.77V

A6
RED/BLK
1208
Left Rear Suspension Position Sensor Voltage Reference4.98V

A7
LT GRN/

WHT
1216
Right Rear Suspension Position Sensor Signal1.88V

A8
LT BLU
1059
Steering Wheel Position Sensor Signal 3.88V

A9
GRY
705
5 Volt ReferenceOK

A10
DK GRN/

WHT
817
Vehicle Speed Signal10.57V

A11
--
--
Not Used

A12
DK BLU/

WHT
1114
Left Rear Suspension Damper Solenoid Control1.6mV

B1
BRN
541
Ignition 3 VoltageOK

B2
LT BLU/

BLK
1206
Left Front Suspension Position Sensor Low Reference6.8mV

B3
PPL/WHT
1211
Right Front Suspension Position Sensor Voltage Reference4.98V

B4
LT BLU/

BLK
1212
Right Front Suspension Position Sensor Low Reference6.8mV

B5
LT GRN/

BLK
1209
Left Rear Suspension Position Sensor Low Reference6.8mV

B6
RED/BLK
1214
Right Rear Suspension Position Sensor Voltage Reference4.98V

B7
LT GRN/

BLK
1215
Right Rear Suspension Position Sensor Low Reference1.97V

B8
ORN/BLK
556
Low Reference1.97V

B9
ORN/BLK
1057
Low Reference6.8mV

B10
--
--
Not Used

B11
TAN
2252
Leveling Pressure Sensor Signal0.429V

B12
--
--
Not Used

All above data collected with ignition on and suspension at zero PSI pressure. I disconnected the 2 sensors for the rear level indicators by unscrewing the 10mm pivot of the rod at the sensor itself. Both are registering within range (0.5 - 4.8Volts). From what I observed, I could not get the exhaust solenoid to do anything by applying ground to B5 (DK BLUE) at the PNK connector. Either with compressor on or off, it doesnt affect the output of air to the shocks. For reference, I manually (I got a switch inside the cab) activated the compressor for about a minute, with key on, here's the data from that test:

-Height from under the hitch receiver: 16 3/4" (I still have the OEM wheels)
-Pressure sensor signal (B11 TAN @ LT BLUE connector): 2.19V
-Rear suspension position sensor signal @ A5+A7 LT BLU 1.23V-1.14V

I find those value a bit on the low end of the scale. The back end of the truck was waaaay high, heck it looked like a souped-up cheapo pinto wagon ready for the dragstrip! I can't really picture how the system can reach the high end of the position+pressure sensors.

So far all checks ok. I'm starting to fear the worst! This will definately require a trip to sumone with a Tech2 scanner to clear DTC's. I might have a code stored in memory from the worn out shocks, thats preventing the system from functionning... I'm gonna sleep on it :D

luxurylife33
09-10-09, 12:17 AM
you really think stored codes would prevent the scm from funcitioning? it makes sense since the dealers want you to bring the car in for service... interesting... i never thought about that.... im still waiting on my buddy to see if he can get me an appointment with his friend/service manager at the chevy dealer...

i will test everything again over the weekend, i been swamped with work.... hopefully sunday i will get a chance to do the tests, but im pretty sure everything is in check. You got me thinking about the stored code issue....

sk7
09-10-09, 05:11 PM
I slept on the problem, and I got me thinking there's only 3 possible codes we have seen listed for the ALC (Automatic Level Control).
DTC C0655 - Air compressor relay - motor non operational
DTC C0660 - Solenoid valve operation
DTC C0711 - Pressure sensor indication.

I was under the impression that a run time of more than 5 minutes from the compressor witout any change in the air pressure sensor's output or a change in the level height, would result in a DTC and disabling of the ALC system. Actually the compressor does shut down, but only till the next time the ignition is cyled off and then on. I'm pretty sure all is well with those 3 codes. Then I found this info, on top of every diagnostic for the ALC, you gotta clear DTC C0870 first, which is reference voltage to all sensors,including the dreaded steering position sensor! Here is the info:

DTC C0870
Circuit Description
The Electronic Suspension Control (ESC) module provides a common regulated voltage of approximately 5 volts to all four of the body-to-wheel suspension position sensors, air pressure sensor and the steering handwheel position/speed sensor. The ESC module monitors this reference voltage for any malfunctions that could prevent it from outputting a regulated 5 volts.

Conditions for Running the DTC
Continuously with the ignition on.

Conditions for Setting the DTC
The ESC module senses a sensor reference voltage of less than 4.0 volts or greater than 6.0 volts.

Action Taken When the DTC Sets
Disable all EVO outputs.
Disable all compressor leveling functions, and assume default pressure.
Disable all suspension damper solenoid outputs.
The SERVICE RIDE CONTROL message will be displayed.
Stores a DTC C0870 in the ESC module memory.
Conditions for Clearing the DTC
The ESC module senses the correct voltage output to the suspension position sensors upon the next ignition cycle.
Using a scan tool.
A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
Diagnostic Aids

Important
Ignition cycle counting is used by the ESC module to detect faults in the system. The objective is to eliminate false/intermittent codes while maintaining an acceptable level of system performance. The operation of the ignition cycle counting requires that a fault condition be present for four consecutive ignition cycles before it will set the fault code and display the "SERVICE RIDE CONTROL" message. If a fault code is present (without a fault being current), the system will go into one or more degraded modes without displaying a message. Resetting the ignition cycle counter is done by clearing codes with a scan tool. Clearing codes will override ignition cycle counting for one ignition cycle. Therefore, a fault condition will set the fault code immediately if it occurs on the first ignition cycle after the codes are cleared.


The following conditions may cause a malfunction to occur:
A short to voltage in any one of the body-to-wheel suspension position sensor reference voltage circuit.
A short to ground in any one of the body-to-wheel suspension position sensor reference voltage circuit.
If the circuit is shorted to ground, the scan tool will display all suspension position sensor voltage as zero.
If the circuit is shorted to an unwanted voltage source, the scan tool may display all suspension position sensor voltage as that voltage.
A short to voltage in the 5 volt reference of the air pressure sensor.
A short to ground in the 5 volt reference of the air pressure sensor.
A short to voltage in the 5 volt reference of the steering handwheel position/speed sensor.
A short to ground in the 5 volt reference of the steering handwheel position/speed sensor.
A intermittent malfunction or DTC may cause a random firm/soft ride condition.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Tests all suspension position sensors reference voltage circuits.

Tests the 5 volt reference circuit of the steering handwheel position/speed sensor for a short to ground and a short to voltage.

Tests the 5 volt reference circuit of the air pressure sensor for a short to ground and a short to voltage.

Clear DTCs and checks to see if DTC will reset.

Step
Action
Yes
No

Schematic Reference: Suspension Controls Schematics Automatic Level Control Suspension Schematics Steering Controls Schematics

1
Did you perform the RTD Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - Real Time Damping

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the suspension position sensors, air pressure sensor, and steering wheel position sensor 5 volt reference data parameters in the ESC module data list.
Does the scan tool indicate that all the above mentioned data parameters are less than 4 volts or greater than 6 volts?
Go to Step 3
Go to Diagnostic Aids

3

Test all 4 body-to-wheel suspension position sensor 5 volt reference circuits for a short to ground and a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 7
Go to Step 4

4
Test the steering handwheel position/speed sensor 5 volt reference circuit for a short to ground and a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 7
Go to Step 5

5
Test the air pressure sensor 5 volt reference circuit for a short to ground and a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 7
Go to Step 6

6
Replace the ESC module. Refer to Electronic Suspension Control Module Replacement .

Did you complete the replacement?
Go to Step 7
--

7
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
Go to Step 2
System OK

This code will disable the ALC. I included a pic of the old shocks I removed, and the SCM module with ID beside the plugs for easier troubleshooting.

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade167.jpg

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade166.jpg

I stopped by another GM dealer (non-cadilllac) where I got my parts for my Blazer K5 build. They will scan and check the SCM for $35. Not too bad... I wanted to borrow the Tech 2 scanner on site, they didnt want... I'll wait for the outcome from your scan session before going that route.

sk7
09-10-09, 08:29 PM
Wiring diagram of the steering input module:

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/STEER.gif

For the sake of science, I unplugged the SCM and turned the ignition on, yipeee a new error message, service ride control!!! There is communication happening afterall... I was worried my out of commission EBCM would overide all error messages (except low fuel level). I will attempt to fool the SCM into thinking all reference 5 volts is ok, if I can find where to do so. I can't see where that reference voltage is for the pressure sensor? More updates to come...

ESKY02
09-10-09, 09:45 PM
Hey guys i havnt done anymore testing. BUT i was talking to a guy at my work and we have a Tech 2 scanner for a work trucks. So this should really help me find the problem...correct?

WSLN 6
09-10-09, 11:22 PM
It should help yes. Let us know what you find out!

sk7
09-11-09, 09:40 AM
You bet! All you need now is a copy of the GM Service manual on DVD. With the Tech2 scanner this will be a piece of cake to figure out whats wrong.

sk7
09-13-09, 10:48 AM
More data taken at the steering sensor:
-ORG (Signal #2) : 2.01V
-GRY (Signal #1): 4.03V
-TAN (5V Ref): 4.90V
-ORG/BLK (Low Ref): 7.6mV
Data was taken ignition on, wheels straight. Voltage does vary moving the steering wheel.


After a quick recheck, all 5V reference for the sensors (4 X ride height position sensors (RHPS), pressure and steering wheel are within specs.) Here is the location of the 5V reference voltage needed to be between 4-6 Volts or else DTCC0870:

LF RHPS: A3 PPL/WHT @ LTBLU Connector SCM module
RF RHPS: B3 PPL/WHT @ LTBLU Connector SCM module
LR RHPS: A6 RED/BLK @ LTBLU Connector SCM module
RR RHPS: B6 RED/BLK @ LTBLU Connector SCM module
Steering input sensor 5V Ref: A9 GRY @ LTBLU Connector SCM module
Pressure sensor 5V Ref: A9 GRY @ PNK Connector SCM module

The investigation continues...

ESKY02
09-13-09, 06:17 PM
I dont have the DVD. I havnt got to plug it in yet, some a**hole keyed the shit out of it. 8500 dollars worth!! whole truck needs to be painted! Thank god my insurance is covering it. Not a happy camper right now!

sk7
09-14-09, 02:00 PM
Wow $8K worth!!! Thats baaaaad, I'm so glad my truck is always in the garage...

I've put all my data, plus a wee bit more info I could gather from the wiring diagrams into an excel document. It will be easier to compare data from other users. My EBCM is due back on wednesday, I want to get this air ride issue resolved afterwards. Got other fish to fry (1955 VW resto).

I've changed the .xls extention to .pdf so it would upload. Just change back the extension of the file to its original format.

ESKY02
09-14-09, 08:54 PM
Ya!! they went across my headlights, taillights, only thing they didnt touch was my brand new 20's, roof, and the running boards...everything else got it!!

EXT04
09-15-09, 06:27 PM
Hey Caddy guys! My air comp didn't kick on when I turned the ign on. I did check all the fuses and they are all fine. I did replace 2 relays. So I did rewire red to blue. Then the comp kicked on. Obviously the comp works fine.
What's next? Should I bring it to the shop and let them scan it with tech 2 scanner? I called Chevy Dealership,they said it costs from 65 bucks to 165 bucks to diagnose for "service ride control". Also I called Cadillac they quoted me from 180 bucks to ??, depending. I don't want to put a lot of $$$ into replacing the air ride stuff like LUXURYLIFE. I just want to find out what the problem is. Thanks

sk7
09-15-09, 07:30 PM
EXT04, you probably read in the post that there's only 3 codes related to the service air ride issue. Compressor not turning on (relay), solenoid exhaust control or air pressure sensor issue. I would like you to unplug all 3 connectors for a few minutes, with ignition off, then replug it and see if the trouble code goes away next ignition cycle. Also you have no sevice stability system issues with your EXT? Thanxs for your help.

EXT04
09-15-09, 11:38 PM
EXT04, you probably read in the post that there's only 3 codes related to the service air ride issue. Compressor not turning on (relay), solenoid exhaust control or air pressure sensor issue. I would like you to unplug all 3 connectors for a few minutes, with ignition off, then replug it and see if the trouble code goes away next ignition cycle. Also you have no sevice stability system issues with your EXT? Thanxs for your help.

Thank you. What about the air pressure switch? I remember when I had my airbagged car the pressure switch wasn't working and the comp wouldn't run. After I replaced it, the comp ran properly. It was a manual one. Where are the solenoid exhaust control and air pressure sensor located? Let me know I can check it out tomorrow.
Sometimes "Stability" message shows up but it's very rare.
Let me know. Thanks Alex

sk7
09-15-09, 11:51 PM
Solenoid exhaust control and air pressure sensor are all located within the air compressor assembly. The pressure sensor is easy to test as the signal for it is at the SCM. I'm still unsure how to test the solenoid, there's a measured value for it in ohms once its unplugged. I tried to ground the control for it at the SCM before, during and after the compressor runs, I can't hear it click nor does it change the output. That will be my next check, I'll take off the compressor assembly and have a look at it.

luxurylife33
09-18-09, 02:42 PM
Well I finally had enough and couldn't wait on my friend to get me to the chevy dealer, so i bit the bullet and took it into the cadillac dealer. After a brief discussion with the service adviser, he said he would on charge 1/2hr labor ($55), i thought WOW, GREAT! so he scans it in about 15 mins and comes back with the compressor being bad. The exhaust solenoid is no good so the compressor needs to be changed. I bought one from Arnott so hopefully thats the end of this 2 month battle with the EXT! The service manager hands me back the keys and says "I did it free of charge" .... THE DEALER SCANNED IT FOR FREE! I couldn't believe my ears... i'll be sure to write his supervisor a good letter!

So for all of you who hardwire the compressor to get it to kick on and think its OK, it doesn't mean the compressor is good. The exhaust solenoid may have a leak or be bad. I would really recommend paying the $55 if you have to to get it scanned. I bought new rear shocks, new front shocks, and a new relay. Before the compressor I was in the hole about $1000 and all I really needed were the rear shocks. Im also happy the rear bilsteins aren't throwing any codes. For future reference the service adviser claims all codes are erased after 50 ignition cycles.

sk7, what a coincidence from your last post ^

sk7
09-18-09, 09:56 PM
Thanxs for the update! I've been buzy today with my ECBM, so far its ECBM 2 - ME zip! I get a new code, C0255, which is apparently solenoid related so the unit will need to be sent away again...

The service manual does point out that the solenoid exhaust is activated each time compressor activity is needed when the pressure is below 10psi in the system. I could not get mine to react manually to any inputs I was giving it. But compressor does pump ok nonetheless. Wonder what's the purpose of this valve? Keep us posted if the new compressor unit does the trick! Hang on to your OEM compressor, maybe the solenoid is an easy fix? I'll have a look into that in the coming days.

DTC C0660 clears when ignition is on and solenoid is ok, and its out of history after 100 ignition cycles if the condition isnt back.

That was a nice gesture of the dealer to scan it for free. So far free and cadillac just don't mix in the same sentence unless you can squeeze the magic "extended warranty" word in there. And that warranty aint free either.

luxurylife33
09-18-09, 10:21 PM
i know right? i couldn't believe it!

I honestly have no need for the compressor so if you want it, pay for shipping and its yours. I'm not going to try and rebuild it.

luxurylife33
09-23-09, 10:03 PM
So I got the compressor from Arnott today, installed it and all is well. I cant believe I didn't go to the dealer to begin with! O well, at least its fixed and the suspension feels brand new! SK7, I will get you a shipping price later this week.

sk7
09-24-09, 11:05 AM
Great, thanxs! I'm sure the Arnott compressor will last longer than the OEM one. If I can't fix mine I'm gonna go with that solution also. If the exhaust solenoid is at fault, which I suspect it is. From my understanding, the SCM does monitor the load on the Dk Blu wire (B5 @ C2 connector) which is the negative trigger for the solenoid. Since it kicks on when compressor is first activated (pressure under 10 PSI), a dead solenoid (no load change upon activation from the SCM) will prevent compressor from starting. But I don't get a service ride control message... Ur truck is pretty much in top shape now?

luxurylife33
09-24-09, 08:13 PM
Yup, back to no problems (no "service ride control" message)! It feels like a brand new truck, I just get a weird feeling starting up the truck and seeing/knowing something is wrong. Im glad I fixed it. If you go with the arnott compressor you'll be happy to find out it runs much quieter than the stock compressor. 2 of the 3 torx bolts to get the compressor off the frame stripped so its strapped there with 4 zip ties until I get a chance to do a bolt extraction on them this weekend. They were rusted to the body pretty good.

You seem to be showing the same symptoms as my truck, I would bet its the same problem. Do the 02's even have a service ride control message system?

sk7
09-24-09, 09:21 PM
Yes it does. I did manage to get the service ride control message after unpluggin all connectors from the SCM and turning the key to the on position. I got the message after the service stability system, ABS, check engine. Going down the highway with cruise control (adds a green light...), it feels like Xmas looking at the dashboard! I will attempt to put a load (control of 20/30A relay) on the output of the SCM to the exhaust solenoid tomorrow. See if that changes anything... Would it be correct to assume that the exhaust solenoid is for lowering the air pressure?

Glad you got all your current issues taken care of. If you plan on keeping your EXT for awhile, the investment in new shocks isnt that bad. Plus you did the work yourself, saved more than the value of the parts put on the truck right there!

sk7
09-29-09, 11:57 AM
Auto Level suspension now working! Just like Luxurylife, my exhaust solenoid was to blame. Here's how to fix it:

From a previous thread, there's 2 ways you can go about removing the compressor assembly. I've removed mine once by taking off the 3 13mm nuts and taking the assembly with frame off the truck. You can also remove the 3 torx T25 screws, but those are a pita to take off (jammed in rust). You don't need to remove the 13mm nuts completely, just unscrew a few turns, then a light knock on the bolt to loosen it, and you can slide the assembly up and out thru a notch. Nice touch... I've realized this upon reassembly as I was trying to manoeuver the compressor in place while being carefull not to knock the bolts back into the frame...

Compressor assembly still on truck with protective rubber blanket removed.

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade187.jpg

With the compressor on the bench, its a lot more convenient to get those T25's off without snapping em off. I admit I was a little more gentle on em then I would of normally since Lux broke off a few. After soaking em a bit in rustoff, I found that applying a bit of heat and SCREWING them made em move just a hair, enough to reapply rustoff, and patiently going back and forth till they come out. All 3 rubbers cushions were completly shot on my unit.

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade188.jpg

With the assembly removed, we can get to test the exhaust solenoid. Ground the frame, and apply +12V to the white wire -12V at the connector. I got no reaction whatsover in my case. Time to investigate further.

Solenoid comes off with 2 T15 torxs screws. Those are metal screws type, so just a little heat to the casing and they came right off. We can see where water came inside the casing thu the wires and messed up the unit.

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade189.jpg

To remove the solenoid from the holder, pry a little on the 4 tabs in the back, then take off the coil from the holder. Watch out for spring and piston in the center. Things were a bit rusty in there but no so bad...

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade190.jpg

Piston and spring:

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade191.jpg

I gently cleaned off all the rust with my dremel tool, cleaned and treated the top of the piston with rubber care (Wurth), re-assembled the solenoid holder and still nothing upon applying current to the unit... I dissassemled again, this time testing for any magnetic activity within the coil itself. Niet! I untaped the coil to get to the connections, then I found the problem: Broken wire caused by corrosion!

http://i438.photobucket.com/albums/qq102/sk7_1969/Escalade/Lade192.jpg

Fixed the broken wire, also did the other side as it was getting weak also. Cleaned the filter within the solenoid, reassembled everything with blue silicone. Reinstall and turn the key on. Doesnt work!! Huuum start the engine, still no go. After a few :rant2: and a couple cold ones, I get to thinking maybe the truck needs to be outta park to activate the compressor? Sure nuff my little red light finally lit up by itself and compressor worked automatically! Yipee!

I now have about 50 pages of notes and data on the SCM and how it works, and all that for a broken coil wire on the solenoid! From my understanding this solenoid, once the coil is activated, recirculates the air from inside the compressor to ease starting the unit. Makes sense! This is why it kick on when the compressor is first activated, if it doesnt the system goes into no go mode. That also explains the rather large current draw at startup when we bypass the compressor at the relay. I'm still uncertain how exactly the SCM can tell if the solenoid is working or not? Once I figure it out, I will make a separate thread on how to diagnose the system.

Heck I deserve a few! :alchi: Thanxs to all who helped!

WSLN 6
09-29-09, 03:53 PM
Wow, nice work! Thanks for the effort, time to go rip mine out as well....

sk7
09-29-09, 07:05 PM
Thanxs! Once the solenoid is functionnal, it really clicks on loudly so its easy to tell if the problem is there or not. Keep us posted!

WSLN 6
09-29-09, 07:43 PM
This should definately be a "sticky" at the top of the page, info for the masses!

ESKY02
10-01-09, 09:49 PM
Hey SK7, After testing and more testing i said forget it. Tonight i put the new compressor in and everything is fine!!! What a relief! I am going to order new shocks, they look ruff. The compressor had the Delco sticker and part number on it! I want those Blistens shocks, anyone have any input on those?

sk7
10-01-09, 10:09 PM
You got your truck back from the paint shop? That exhaust solenoid is sure the weak link in the auto level suspension system. Something to keep an eye on...

ESKY02
10-01-09, 10:43 PM
Yah got it back a day ago. I was surprised how fast they did it.

luxurylife33
10-02-09, 12:07 AM
I installed the rear bilsteins. I would say theyre better than the OEM ones, but my OEM's leaked and I dont know for how long. But they ride really nice. SK7, glad you figured out the problem! Did you still want that compressor? And also I realized there is an audible click about 1-2 seconds before the compressor kicks on... I guess that is the sensor .... glad you solved the problem! .... and maybe it might be something to further look into but my compressor activates in park....

WSLN 6
10-04-09, 04:20 PM
Well, mine is fixed now as well! Exact same problem, blue wire lead broke really close to the windings, quite tricky to solder. I re-soldered both leads as they didn't ohm out properly, after all was done it was 21 ohms for the coil.
My coil was a bit differen though.....it had a green o-ring lol.
One other problem I found was that the short ground wire was open internally as well, even though it looked ok. Replaced, and all grounds were lovely again.
Once you install the compressor again, don't forget the small spring retainer clip on the pressure side.... grgrgrgrgrgrgr pssssssssssssssssssh. Works much better when the line stays on lol.
Thanks guys! Time to order some new shocks now I guess. :crying:

sk7
10-04-09, 08:19 PM
Glad to know! Good call on that ground wire, I also tho it looked suspiciously rusty... But it tested ok. System works great still, but compressor kicks on (I kept my red led in the dash to monitor compressor run status) always differently when taking off first drive of the day. Sometimes its as soon as I get into reverse, sometimes it takes 4-5 seconds before it goes, weird...

WSLN 6
10-05-09, 10:29 AM
Just did the same fix to a friends 2005 Denali. Same problem, blue wire lead broke off. His setup was missing the ground wire completely. We added one just in case. Works great again!

EXT04
10-05-09, 04:45 PM
Hey SK7. I took the solenoid out and saw the 2 wires which seemed ok. I played around with the 1 wire, after moving it, it broke easily. So I decided to resoder both wires then I installed it back. It runs and no Service ride control yay. It drives like new again. Thank you very much. It's a free fix.

auberypn
11-13-09, 11:45 AM
Hey guys,any added insight to what was already said,because i checked the right rear seat,no luck. Do you know if the 2003 has the same arrangement as the2002.Thanks.

luxurylife33
11-13-09, 12:17 PM
It should be there. On your EXT lift the right rear seat and youll see a tan box, thats the SCM if your looking for it. Open up the plastic and its snug inside there.

( I also have a 2003 EXT )

03Escalade
11-16-09, 09:12 PM
Hey guys.. thanks to those who have been helpful on this thread. I believe my problem is the compressor is no good. 12V across it and nothing. I live in Massachusetts and they drop ALOT of salt in the winter on the roads. It's all corroded and probably got wet and blew. Ordered a new one off ebay for $180. Hopefully thats all I need to replace..

sk7
11-17-09, 05:22 PM
Yeah thats corroded allright! You might wanna remove the bracket and compressor assembly as one, so you can get to work on those small tork bolts on the workbench. They break easy! There's 3 13mm bolts to unscrew from inside the frame rail. No need to remove them all, just loosen and slide out the complete assembly. I was able to remove the tork bolts by heating them up a little and screwing them a little bit so they would move, add ur favorite rust remover, and easy does it.

WSLN 6
11-18-09, 09:12 AM
Well my fix lasted about 2 weeks or so and the same thing happened. Wire corroded from moisture and broke in 2 spots on the solenoid. Resoldered again and added a bunch of dielectric grease to prevent the problem again. Here's to hoping!

sk7
11-18-09, 06:59 PM
Mine still working good! I did redo the 2 wires for the solenoid and added silicone to keep water outta there. I dunno how long it will last thru winter... I put antiseize on all the bolts (always do) so it will be a piece of cake to get to the solenoid next time around.

03Escalade
11-21-09, 03:31 PM
Yeah thats corroded allright! You might wanna remove the bracket and compressor assembly as one, so you can get to work on those small tork bolts on the workbench. They break easy! There's 3 13mm bolts to unscrew from inside the frame rail. No need to remove them all, just loosen and slide out the complete assembly. I was able to remove the tork bolts by heating them up a little and screwing them a little bit so they would move, add ur favorite rust remover, and easy does it.

DONE! As I suspected the motor was the only issue I had. The new one is in and it works perfect. Not as loud as the factory one which is a good thing I guess. The 3 tork bolts did not come out easy at all.. I had to cut 2 of the heads off and drill one out, but with some new hardware I'm good to go. The replacement pump I bought came with the 3 rubber pieces so hopefully it wont crap out again. Next up I need to figure out why the Air Bag light is on.. it turned on outa the blue the other day. Hopefully nothing major.

sk7
11-21-09, 06:04 PM
Great news! I did notice a few members here saying the replacement compressors are a lot quieter... I know all the rubber bushings were shot on mine. You might want to check krazykeith post about airbag issue, it was one of the sensors in the front bumper.

auberypn
12-05-09, 09:14 PM
NEED HELP! My compressor is working, i replace my shocks with Arnott replacement,but still seems to have the service ride control light on the dashboard,what you guys think is still the problem,should i replace the bcm,or what is the soleniod on the compressor,because i know the air is comming out from it, and is there any current that goes to the shocks that could be tested by a tester, i am just confused and really need some help on this one,and would appreciate any help! thanks work shops sometimes gives u a wrong diagnosis,that happen to me,before i found this site.Thanks once again

auberypn
12-05-09, 09:18 PM
and i forgot what are the height sensor,and where is it located.

luxurylife33
12-05-09, 10:52 PM
How do you know the compressor is working? Did you hardwire 12 volts to it? or is it turning on on its own?

snatchman
12-06-09, 12:06 PM
WOW! There is not to many forum threads I have read completly thru, but this one was very informative. I am having the exact same problem as most of you with my 03 EXT. I guess it's time to break out the 13mm wrench and get to work. I will keep you posted.

sk7
12-06-09, 12:37 PM
I admit its a bit of a looong thread to read. I will eventually re-write a how to on the air ride issues. Auberypn, if you compressor automatically comes on when you first drive off in the morning, that's a good sign! The exhaust solenoid is working properly. Other issue could be the pressure sensor, or the position sensors. If either one doesn't increase after a set run time of the compressor, system will shut down and service ride control comes on. Isn't there a bypass for the sensors (ride control solenoid) to install on the oem harness that comes with your arnott shocks?

dstinson
12-06-09, 05:34 PM
I think this is the longest thread ever... I have an 03 with the Arnott shocks as well, it does come with a module that you need to take the 2 wires from the shocks (and I hate to say) cut them and then splice them in the module (black box thing the shocks come with). I too still have the service ride message, but I have a manual switch in the truck that I use to put air in the shocks. I think I need to look at the dryer next, but since I can manually put air in them I have been waiting to see if anyone else had the same issue as me before I go exploring again. I have always been a bit fuzzy on the height sensors as some people have them bent and others do not and it doesnt seem to be one common way of doing things to make it properly function(I have 3 sets of rods all diff lengths now). good luck!

luxurylife33
12-06-09, 06:26 PM
99% of these problems you guys have are going to be that little solenoid in the compressor. Seems like a VERY common problem. Arnott sells a compressor for $179 shipped on eBay that took care of my problem. Comes with a 1 year warranty and runs about 50% quieter than the stock compressor. You can barely hear it.

pearl04
12-07-09, 05:37 PM
My escalade had a C0660 body code from the service ride message (Exhaust Soleniod). Replaced my compressor with one from Arnott, it is considerably quieter than factory. If you use "74V4-W7D" as your coupon code on Arnott's website it will give you 10% your order.

luxurylife33
12-07-09, 09:48 PM
My escalade had a C0660 body code from the service ride message (Exhaust Soleniod). Replaced my compressor with one from Arnott, it is considerably quieter than factory. If you use "74V4-W7D" as your coupon code on Arnott's website it will give you 10% your order.

DAMMMMMMMMIT I bought 2 front shocks 2 rear shocks and a compressor from them! That's about $100 I could have saved.... SHIT

auberypn
12-08-09, 10:30 AM
thanks guys,i replace the compressor (arnott) it works great, but service ride control still appears,iguessed i will have to disconect the scm and see if i get i different reading.You guys are indeed the true tecnichan,without these tread people will have to spend o lots of $$$$$$ to get things fixed. I appreciate sincere! thanks once again

auberypn
12-08-09, 10:39 AM
Sorry sk7 my computer was giving me some problem so i was unable to respond ,but like i said i changed the compressor ,and is now checking at the sensors. Thanks ! and these post are so long that i do gorget which page i am on,is hard to keep up.THANKS.:alchi:

sk7
12-08-09, 11:18 AM
No prob! How long does the compressor run for when truck is first started in the morning? Does it come on randomly afterwards while u drive? When exactly does the SRC message appear? Always the same pattern? Checking the 5V reference for the 2 rear level indicators and pressure sensor would be a good place to start.

After a few coooold ones I do become a good technician lol! Problem is no one else shares my opinion at that point... I believe was are a bunch of handy DIY guys who won't put up with paying high $$$ to have someone service our trucks. Strenght in numbers, this site should be sponsored by cadillac!

auberypn
12-08-09, 11:48 PM
WOW! i think pay will be negotiated. I dont know where to check for the position sensor or the pressure sensor,i spend sometime today looking to see if i can come up with something to have the src light disappear,but like its a good relationship until it gone bad. Could u tell mewhere those sensors are located. I WAS THINKING TO TAKE IT TO A DIAGNOTIC CENTER TOMOROW! PAY ABOUT 40 BUCKS,and see if tey come up with something. if the response is early ,i will check in before going.i appreciate sk7. thanks. Remember i now have the arnott (works great)shortly after turning on the ignit, the light appear

sk7
12-09-09, 12:22 PM
There's only 3 possible codes for the auto leveling suspension. I pretty sure I posted the diagram for the plug at the SCM, I think its under the rear seat in the EXT. I would try and save my $$$ for a diagnostic readout as much as possible (yes I'm cheap!). Did you connect that bypass for the sensors that came with ur shocks? If you didnt then the 5V reference is no longer there and you will get an error message from the SCM. There's a solenoid in the OEM shocks that is controlled by the SCM that vary the damping according to road conditions (readout on speed, yaw sensor, steering input, and level sensors). This device is not in the Arnotts replacement shocks, so you need to fool the SCM into thinking that all is well with the solenoid.

auberypn
12-09-09, 09:53 PM
Being in the natural world is good,but things are sometimes complicated and need further knowledge,but i am intent to learn. My arnott shocks cost 479 bucks,compressor 179,plus shipping did it all by myself,compare to the dealer i am still way ahead,so tomorow i am going to attemp your solution,hopefully is the same thing we are talking about.! I discover the scm but dont have a clue in electronics,or wireing,but would appreciate any idea,to get me off that message, i will have to know how the system works so i can apply the very priciple u have outlined!. Should i start with the wire from the relay (disconected) and take it direct to the scm with wire unplug,agood way to start for me,then i will procede. I WANT TO BE OFF COURSE FOR AWHIL,I GOT SOME SYNTEC MOTOR OIL FOR FREE AND CHANGED MINE TODAY DO U KNOW HOW TO RESET THE PERCENTAGE OF THE OIL FOR READING 100%.THANKS!. And dont forget cheapnis comes from within.

sk7
12-09-09, 10:06 PM
The reset for the oil is done with the key on and pressing the gaz pedal to the floor so many times in less than 5 seconds. At least that's how it is on my 02, could be different on the 03 and up. Owners manual should point that out.

You will need a digital multimeter to read 5V reference at the scm. But maybe you won't need to. So you got a new compressor and new shocks in the back installed, and the compressor still doesnt work automatically and you get a SRC message? The compressor has never worked since the install?

Its a good thing to try and work things out by yourself. With a few basic tools, a bit of help from this forum, and patience, you'll figure it out! And it's rewarding to know how the system works for future breakdowns...

luxurylife33
12-10-09, 12:20 AM
On the 03+ use the steering wheel controls to get the oil % to show. With the % showing, press and hold the "enter" or arrow looking button for about 5 seconds (until it resets to 100%).

auberypn
12-10-09, 08:56 AM
You guys are terriffic,i will attemp it again today if giving the oppertunity to do so,but i will keep u posted of the outcome,i think something is going to work out,determency would be challenge,so gold completed.Thanks once again. You wouldnt beleived something i am in a mechanic shop (body work) and the guys like me dont have a clue.

auberypn
12-11-09, 11:59 AM
Thanks for the help with the oil %,thats fine,i will try and see about the src this weekend GM wanted $98.00 to $144.00 to do the diagnostic,but money is hard to find. I keep u posted. Thanks!

auberypn
12-12-09, 10:54 AM
Back once again! i think i will have to get a diagnostic done,my src was on for to a longggggggggg time, and i remember i was told by strutmaster that it would affect the front eventualy, mine looks a bit shady,and would have to make a decision wether to pay gm price or to just get a pair of front,and hope it diss,.appear. oil reset was a success.Thanks

pearl04
12-19-09, 10:30 AM
There's only 3 possible codes for the auto leveling suspension. I pretty sure I posted the diagram for the plug at the SCM, I think its under the rear seat in the EXT. I would try and save my $$$ for a diagnostic readout as much as possible (yes I'm cheap!). Did you connect that bypass for the sensors that came with ur shocks? If you didnt then the 5V reference is no longer there and you will get an error message from the SCM. There's a solenoid in the OEM shocks that is controlled by the SCM that vary the damping according to road conditions (readout on speed, yaw sensor, steering input, and level sensors). This device is not in the Arnotts replacement shocks, so you need to fool the SCM into thinking that all is well with the solenoid.

Originally had C0660 code...Replaced compressor with one from Arnott, everything went well, no service ride control, etc....Noticed the rear shocks were leaking pretty bad so I ordered a set from Arnott, installed 2 nights ago and now I'm getting a service ride control message again....The shocks I received from Arnott did not have any type of "bypass" for my shocks????

sk7
12-19-09, 08:01 PM
Is there a spot on the Arnotts to plug in the wire for the solenoid control? Its a 3 wire plug.

pearl04
12-19-09, 11:03 PM
yes the factory plug, plugs into the Arnott shock

sk7
12-20-09, 02:30 AM
Had a look at the Arnott website, only models listed (arnott-bilstein) are the ones without the solenoid control. They do come with the bypass to plug into the harness.

http://www.arnottindustries.com/part_CADILLAC_Air_Suspension_Parts_yid6_pid77_gid5 03.html

luxurylife33
12-20-09, 11:36 AM
Maybe they changed it so that you can just plug it straight into the factory harness? That would've been good in August when I bought them! Its actually a 2 wire harness, not 3. I had to splice mine in. Can you post a pic of the shocks you got?

pearl04
12-20-09, 11:49 AM
When I purchased my shocks from Arnott they still had available the factory replacement style shocks....They say Delphi on them and look exactly like the factory shocks I replaced. The replacement shocks from Arnott have the plug on the top of the shock that allows you to plug in the factory harness without any splicing. Since then, they have taken those off there website and now they only offer the Bilstein.

luxurylife33
12-20-09, 12:52 PM
O ok so you have OEM GM shocks. Those are right from the dealer (Arnott must have bought all of GM's overstock shocks a few years ago). They are NOT Bilstein or Arnott shocks. I noticed they want a core charge of $50 for their bilsteins so maybe they are going to start rebuilding them? I guess they ran out of the OEM shocks.

sk7
12-20-09, 08:36 PM
Oem shocks it is! There's only one area that can cause the SCM to fail and give an error message, and that would be the 5V reference to the shocks solenoid. That's an easy check at the SCM. Once you have read the values for both sides (with ignition on), you can repeat the test with the shocks you took off (if you still have em) and compare. Keep us posted.

auberypn
12-20-09, 10:57 PM
i had my diagnostic done,and the dealership informed me it was the seal for the alc between the dryer and compressor that were missing! no more src, but the delphi from arnott already has a built in solenoid, the ones they removed from their website,but if anyone gets the problem,once u take it to the dealers they will want ot fix it. THE BEST SHOT IS TO INSTALL THE SHOCKS YOURSELF(EASY),AND IF SRC REMAINS,then take it to the dealer have a diagnostic done,then u can take it from there. Suncore industries .com have shocks for $299.for one,not bad

pearl04
12-21-09, 03:40 PM
I took it by the dealer this morning and they scanned it for free. They said they just had to reset something with the scanner. Drove home with no src message. Hopefully it doesn't come back on.

auberypn
12-22-09, 01:02 AM
all of us are not lucky, i had to pay $160. dollars, and now i have engine light on

Rage
01-14-10, 05:11 AM
Thanks everyone for the amazingly informative thread...

Okay, I have replaced the compressor(Arnott), rear shocks to Billstiens, and front shocks (OEM). The "SRC" message dissapeared but I still feel that air is not being pumped into the rear shocks. I have checked the lines for any cracks for leaks and found none. At first start I do hear the compressor coming on for a few seconds but it doesn't seem to lift or fill the rear. I do faintly hear a hissing sound like an air leak but cant seem to locate it. My guess would be the dryer since that was the only item that was not replaced. Could the dryer leak air and not fill the shocks? Is it possible that the dryer caused damaged to the compressor in the first place? Where else could the leak be coming from?

I am going to see if I can get the dryer here locally since the shipping is as much as the item...

Any help is greatly appreciated!! Thanks

sk7
01-14-10, 09:50 AM
Maybe there's something blocking the airlines to the shocks? You can unplug them both and bypass the relay to see if any air does get to the shocks. The pressure sensor is on the compressor. If the system does come on automatically that's a good sign. Compressor run time is about 10-12 seconds in my case (more like 20-25 if all the family is inside with the mother in law...) upon first morning startup. I was under the impression the dryer is part of the compressor assembly? If you get no SRC code something is telling the compressor the height is ok. Can't remember if the pressure switch or the level switch has priority. Keep us posted!

Rage
01-22-10, 09:43 PM
Maybe there's something blocking the airlines to the shocks? You can unplug them both and bypass the relay to see if any air does get to the shocks. The pressure sensor is on the compressor. If the system does come on automatically that's a good sign. Compressor run time is about 10-12 seconds in my case (more like 20-25 if all the family is inside with the mother in law...) upon first morning startup. I was under the impression the dryer is part of the compressor assembly? If you get no SRC code something is telling the compressor the height is ok. Can't remember if the pressure switch or the level switch has priority. Keep us posted!

SK7,

Update... Finally, I just replaced the Dryer and no hissing sound/ leaking air!!! Airshocks work great. Thanks again for this thread and your help :bouncy:

sk7
01-22-10, 10:47 PM
Thanxs for the update. Glad to know its working!

hybridpower
02-07-10, 12:47 AM
Hi Guys, Maybe you can help me get started. I have a 2002, and the air compressor doesn't come on at all, but I don't have any warning lights? I have power at the "air" fuse, and also at one wire in the relay (though not at either of the red wires with the key on). I verified this with a test light. I did not jump power to either red wire, as I was not sure which was which and did not want to damage anything.

Any ideas where to start?

luxurylife33
02-07-10, 02:49 AM
Take the compressor down and hook up 12v to it..... if it doesn't power on, its the compressor that shot. If the fuse and relay get power, chances are its trying to turn the compressor on.

hybridpower
02-07-10, 11:48 AM
Thanks. I'll try that. I'm also going to try to jump the red wires better to see if I can get it to kick on without pulling it down.

Does the 2002 need to be out of park to come on?

hybridpower
02-07-10, 12:51 PM
Ok, I tried to jump the red to red, but nothing happened. I also put the test light on the jumper and I don't seem to have any power going from Red to Red; does this mean the unit is not calling for the compressor to be turned on?

A few other points. I do have power on the brown wire, and the red wire closest to the brown is grounded (will complete a circut with the test light). Given this, is there any reason to pull down the compressor, or is the system not trying to turn it on at all?

Thanks,

luxurylife33
02-07-10, 12:53 PM
If you jumped the wire at the relay and it doesn't turn on, then your compressor is shot. $179 on eBay or on Arnotts website (you save shipping costs on ebay w/ free shipping). 30 mins of labor, very easy.

hybridpower
02-07-10, 01:17 PM
Even if I don't seem to have power at the red wires? Are they the power source or the trigger? I can put the test light on either red wire (after removing the relay) and not get the test light to come on. Only the brown wire has power?

luxurylife33
02-07-10, 01:47 PM
The only way to know for sure is to just take the compressor down and test it...

sk7
02-08-10, 07:42 PM
You should have constant 12V power at the relay, if I recall correctly from Stud1 fuse. Maybe it was taken off? Brown will be on off 12V with accessories, light blue negative trigger from the SCM. If the fuse is shot, compressor is probably seized.

hybridpower
02-09-10, 11:30 AM
I have power at the 30 amp fuse in the block and I have Power on (what I assume) is the trigger wire on the relay when the key is on. What I don't have is power on either of the red wires. Can someone verify if they have power on the red wires? I have jumpered from red to red, with no result, but that would not produce a result (unless I misunderstand something) because I am not jumping any power to the compressor. Is there anouther fuse that supplies power to the red wires that might be blown?

If I pull the compressor to check it, how did you supply power? Did you jump to the plug, or directly to the compressor body? Did you use a battery, or can I do it with a trickle charger? I just don't want to burn up or damage something else.

Thanks guys.

sk7
02-09-10, 05:20 PM
Power at the relay is constant 12V, jumping the 2 big wires should make the compressor run. If there's no 12V at the relay and the fuse is good, something is wrong under the fusebox, you can then try to feed 12V from your fusebox to the compressor via the relay socket. Post some pics of what you've done-tested so far if possible.

hybridpower
02-09-10, 10:41 PM
Well, good news! I was taking photos to respond to Sk7, and what you said in your last post prompted me to check a few things. I pulled the fuse and what you said is correct; key on, or key off (or even "air" fuse out), the relay had 12v on the brown wire. But regardless of that, I had no voltage on the red wires. I let that sink in for a minute, and went in search for the lack of power on the red wires.

I hate to admit it, but it was a simple solution...a blown fuse. I got so caught up in looking for a "real" problem, that I ignored the simple solution. Changed the fuse, and the compressor fired right up.

Thanks again for everyone's help and input, I'm sure I'll be back with a "real" problem one of these days!

sk7
02-10-10, 05:47 PM
Good news thanxs for the update!

roboteacher
03-09-10, 01:11 AM
I've read this thread about 3 times and can't wait for my new compressor to come in. What a great thread.

cadomine03
08-07-10, 06:53 PM
Thanks for all the great info,turns out the pump was bad.It would run when you by-passed the relay.When I installed a new relay there was no change and still a SRC in message center .I removed the pump assembly and when I opened up the dryer it was contaminated by moisture and the inside of the pump unit was severely oxidized.A call to Arnott $179.00 + an hours labor by me = one happy 'slade owner.Thanks again guys

erod03
08-27-10, 01:09 PM
Hello guys im new to this website and need help. My 2003 escalade air suspension compressor doesnt turn on and my light is on. i have gotten as far as checking all fuses and finding the relay under the fuse box. what should i do to find out if my compressor is bad without removing it from truck. what tools should i buy to make it a fast check and repair. thanks

sk7
08-27-10, 08:14 PM
Welcome! First thing I would try is jumping power at the motor thru the relay. If the compressor activates then its most likely the exhaust solenoid. If noting happens and stud 1 fuse is ok, you will need a new compressor. You need to take the unit off the truck for repairs either way. Easy nuff to do with basic handtools. Keep us posted!

erod03
08-27-10, 10:06 PM
Welcome! First thing I would try is jumping power at the motor thru the relay. If the compressor activates then its most likely the exhaust solenoid. If noting happens and stud 1 fuse is ok, you will need a new compressor. You need to take the unit off the truck for repairs either way. Easy nuff to do with basic handtools. Keep us posted!

IDK if im doing it correct but i removed the relay by the Fuze box in engine. i ran a wire to the red wire to power and nothing. i also check the red wire before it connect to the compressor with fuse check light and it turns on. would this mean my compressor is bad. sorry if i ask the same question. i just want to know before i spend $$$$ to repair this. Thanks

sk7
08-28-10, 01:51 AM
At the relay socket, once the relay is removed, use a small lenght of 10GA wire to jump the 2 bigger wires together. If you got 12V power at the relay (with ignition off) means stud one fuse is good. If nothing happens check at the harness to the compressor for 12V power and also that ground is ok.

erod03
08-30-10, 08:21 PM
At the relay socket, once the relay is removed, use a small lenght of 10GA wire to jump the 2 bigger wires together. If you got 12V power at the relay (with ignition off) means stud one fuse is good. If nothing happens check at the harness to the compressor for 12V power and also that ground is ok.

well the compressor turned on with the truck off..would that mean relay is bad? i checked the relay socket (red wire) and get power. idk what else to check

sk7
08-31-10, 08:29 PM
To check the relay, apply ground to the small blue wire while the ignition is on. If that works your exhaust solenoid on the compressor is probably faulty.

erod03
09-01-10, 12:26 PM
To check the relay, apply ground to the small blue wire while the ignition is on. If that works your exhaust solenoid on the compressor is probably faulty.
if the exhaust solenoid is out would that mean i need a new compressor or can i just buy the solenoid? thanks

sk7
09-01-10, 09:38 PM
You cannot purchase solenoid separately. It's a pretty easy fix if you have basic handbooks and soldering iron. Moisture inside the unit causes the wires to fail. I posted pics previously. If u already have or can borrow the tools it's a free fix! Go for it. Worse case scenario u will have to get a replacement from Arnotts. By then u will know how to remove the unit so u can reinstall yourself.

erod03
09-02-10, 01:29 PM
You cannot purchase solenoid separately. It's a pretty easy fix if you have basic handbooks and soldering iron. Moisture inside the unit causes the wires to fail. I posted pics previously. If u already have or can borrow the tools it's a free fix! Go for it. Worse case scenario u will have to get a replacement from Arnotts. By then u will know how to remove the unit so u can reinstall yourself.

well i threw the white towel in. the solenoid i think is faulty. i did what you posted and tried removing the cover around the coil but dang that mug is welded together. im just going to order a new compressor. would it be okay to drive the truck without the compressor on it.

sk7
09-03-10, 10:26 AM
I drove mine for a few weeks with a bad compressor and thrashed rear shocks. Didn't really notice it but the ride and handling sure improved once all was working!

2caddy23
09-07-10, 06:30 PM
This is one of the best write up's.It solved my problem very quickly.THANK YOU

erod03
09-09-10, 01:08 PM
I drove mine for a few weeks with a bad compressor and thrashed rear shocks. Didn't really notice it but the ride and handling sure improved once all was working!

thanks for the help...i fixed the proplem but how can you tell if theirs a leak in the shocks? i sprayed some water mixed with soap on the shocks to see if it would leak but didnt see anything what another sign i can use. thanks

sk7
09-10-10, 10:24 AM
I think you are all set! A minor leak won't cause the SRC light to come on, unless the compressor runs for a set lenght of time (2 minutes I think) with no change in the ride height.

spankeyis
09-28-10, 12:02 AM
I give up...I have replaced the air pump, jumped the relay (it works) and replaced the SCM and I still cannot get the compressor to kick on or clear the SRC error. I checked the air lines for free flow of air and they are good. Dealer first said it was the air pump (so I replaced with ARNOTT pump) and then said it was the SCM so I replaced that (online - guaranteed) and still the compressor will not kick on without jumping it at the relay. What am I missing? Pressure switch? I am stumped.

CaddyEscalade
09-28-10, 03:04 AM
I am also in the same boat. I have replaced the compressor with a new Arnott today still nothing. If I jump the relay it will come on so I installed a bypass switch at the relay to manually activate the compressor, but I still want it working right. It was working on its own the odd time, now it has stopped. My wife said the service ride control message came on once, but I have not seen it since. Come on, I have read this thread from the start, and I am almost ready to give up. HELP!

spankeyis
09-28-10, 10:12 AM
I know. I would read through the posts and then try whatever I read. Nothing. I am going to test the pressure switch today. I am almost convinced that is the issue. Wouldnt the pressure switch prevent the compressor from kicking on if it is faulty? My dryer was in really bad comdition when I replaced the compressor. I cleaned it up with the rebuild kit but didnt replace the ps as I bought the Arnott and not the stealer compressor.

sk7
09-28-10, 01:16 PM
A faulty pressure switch or faulty level sensors will prevent the compressor from activating. Did you have your replacement SCM module programmed to your truck with a Tech2 scanner? If that module is brand new, it needs to be programmed (according to the FSM). If I were you I would put back the OEM SCM module there. Check the 5V reference at the SCM for the pressure sensor and the level sensors, with key on, then activate the compressor manually till the back end raises a bit and compare readings. Any difference? Another test is to check if you get negative trigger from the SCM at the underhood relay. Could be as simple as a bad relay. Post back results. Good luck!

spankeyis
09-28-10, 09:08 PM
For clarification, What is the 5v reference? also, the SCM was used but guaranteed to work. It came out of a caddy but same PN as mine. Would I have to reprogram? I have had it to 2 dealers. One said air pump, After I replaced that, Second dealer said SCM. Now here I am and still not working. I hesitate to go to the dealer a third time

sk7
09-29-10, 12:56 AM
Most of the sensors associated with the SCM work on a 5 volts reference at the module. I recall they do not vary much... I still got dozen of pages of notes when I troubleshooted my system last year. You will need to identify the inputs according to the diagrams posted elsewhere on this thread. Once again I would start with the original SCM module. Replacing it didnt solve your problem. Post those before and after data for the level indicator + pressure switch and we can take it from there.

CaddyEscalade
09-29-10, 02:45 AM
I will post my voltages from all the wires on the SCM below. It would appear that my rear level sensors may be a problem(if I am reading things right) .51 volts and .67 volts, the pressure sensor is .41 volts with no air and .53 volts after I added about 20 seconds on the compressor manually. See my results below, the first number is no air and the second is once I added about 20 seconds from the compressor with my manual switch.

BLUE PLUG
A1 PINK/WHT—1.011, 1.10
A2 LTBRN/WHT.97, .90
A3 PUR/WHT 4.97
A4 LTBRN/WHT .95
A5 GRN/WHT.67, .62
A6 RED/BLK4.97
A7 GRN/WHT.51
A8 NOT USED
A12 DRKBLU/WHT 0 VOLTS

B1 BRN --12 VOLT 11.4
B2 LTBLU/BLK 0.04
B3 PUR/WHT 4.97
B4 LTBLU/BLK .04
B5 GRN/BLK 4.97
B6 RED/BLK 4.97
B7 GRN/BLK .04
B8 NOT USED
B11 LTBRN .41, .53

PINK PLUG
A1-A8 NOT USED
A9 GREY 4.97
A10 LTBLU 0 VOLTS
A11 NOT USED
A12 LTBLU/WHT 0.VOLTS

B1 BLU/WHT 0 VOLTS
B2 WHT .12 .15
B3 NOT USED
B4 LTBLU .12, .15
B5 DRKBLU 10.03, 10.14
B6 GRN .11, .15
B7 NOT USED
B8 DRKBLU/WHT .43 -.6, VOLT FLUCTUATION
B9 NOT USED
B10 BLK .04
B11 NOT USED
B12 NOT USED

GREY PLUG
A-LIGHTBLUE/WHITE 0 volts
B-GREEN 0 volts
C-BLACK 0.04 VOLTS
D-ORANGE 11.3
E-BLACK 0
F-GREY 0
G-GREY 0
H-GREEN 0

I just don't understand the 5 volt reference lingo, and really don't know what to do with any of this voltage information. I also had access to a friends 2006 EXT and I swapped the SCMs and can confirm it will operate. I swapped them, and the problem stayed the same in my Escalade, but my SCM worked fine in his EXT with the air ride. So this should also eleminate the SCM as the problem as well. So far this is where I am at, replaced compressor with Arnott's, new OEM shocks, SCM, have no air leakage, installed a manual switch at the relay, Stud 1 and ign3 fuses are good, and there is no Service errors on the information centre. I have not checked the rear level sensors by the tires, but I am not sure what I am looking for. This is getting personal now, I must beat this!!

sk7
09-29-10, 03:19 PM
Good job! Your manual switch at the relay provides ground to the blue wire coming from the SCM? Just want to make sure that's not part of the problem (faulty relay). The level sensors are easy to spot, inner wheel well there's a small metal rod attached to a variable rheostat. You can fool the SCM into thinking the back end is dropped to the floor by unsnapping the end of the rod and holding it in the up position with a piece of coat hanger. This should get the system going. If this doesnt work the exhaust solenoid should click when activated manually at the SCM plug (jump wire). Has this replacement compressor ever worked automatically? You WILL beat this!!

CaddyEscalade
09-29-10, 03:55 PM
I also tried swapping the relays from my friends truck and that is also not the problem. My manual switch just connects the 2 larger wires that people jump. What wires do I jump for the exhaust solonoid at the SCM? Is there any other wires I can try jumping at the SCM to try and eliminate anything else? This new compressor has never worked manually, I just replaced it because of this problem with an Arnott one. As it would appear my old compressor is fine since the problem still remains. Thanks for your help, this is going to kill me.

sk7
09-29-10, 08:07 PM
I'm gonna have to go thru my notes on this one, but one thing I would try is check if the SCM sends a ground trigger at the relay. That would eliminate the solenoid issue. Easy to do with a regular test light. Wire is blue in color, but I think it was different on the EXT. After fixing the solenoid I could activate it at the plug on the compressor assembly. The other smaller wire on the relay should be brown as is switched accessory 12V.

CaddyEscalade
09-29-10, 09:51 PM
I am not sure I understand what you are saying. "check if the SCM sends a ground trigger at the relay. Easy to do with a regular test light." Forgive me but how do I do this? I have a test light and a volt meter.

CaddyEscalade
09-29-10, 10:27 PM
I'm gonna have to go thru my notes on this one, but one thing I would try is check if the SCM sends a ground trigger at the relay. That would eliminate the solenoid issue. Easy to do with a regular test light. Wire is blue in color, but I think it was different on the EXT. After fixing the solenoid I could activate it at the plug on the compressor assembly. The other smaller wire on the relay should be brown as is switched accessory 12V.

I might have just found something. With the iginition on I do not have any power at the small brown accessory wire at the relay plug when the key is turned on. I just have constant power at the big wire. Phoned my buddy to check his and he gets power on the small brown wire at the relay plug when thyey key is turned on.

CaddyEscalade
09-29-10, 11:23 PM
Oh, and yes I have checked and tested my ign3 fuse and also tested the wire at the scm, both are good with 12 volts.

sk7
09-30-10, 12:29 AM
Ok got my bundle of papers from the attic of the garage lol! I don't have the EXT wiring diagram tho, and I'm pretty sure the trigger wire for the relay from the SCM is a different color than the regular escalade. Anyways on your relay, one of the 2 smaller wires should have 12V when key is on. The other one will be the trigger (negative latched on-off) from the SCM. If there's no 12V to one of the smaller wires, ur on to sumthin! There's a small ALC fuse in the underhood fusebox, not sure if that one feeds power thru there. I'll have to check.

You can trigger the exhaust solenoid by applying ground to the Pink wire location B5 @ C2. When key on there should be a faint click heard. You can try on ur buddys truck if he's willing... If nothing happens check for power at the orange wire @ the compressor assembly. Its a contant 12V source no matter what. If there's no power there, check 30A fuse RTD underhood fuseblock. To check if the SCM does trigger the relay, put the alligator clip on the positive side of the battery, and insert tip of the test light under the socket of the relay so it makes contact with the wire (the one that's not getting 12V positive when key is on). Switching the key on (in my case I gotta hit the brakes sumtimes and shift outta park for the compressor to start working) the test light should illuminate to tell you the SCM is sending command for the compressor to start. That test clears the exhaust solenoid as the culprit! To be continued...

CaddyEscalade
09-30-10, 03:31 AM
IT'S FIXED! :) After all that is ended up being that huge plug under the truck with all the SCM wires (by the back bumper on a regular Escalade) that was coroded real bad and full of dirt. I cut all the wires off (a few at a time) and removed that plug spliced them all together and bingo the compressor was awake!! Thank you sk7 your attention was greatly appreciated and got me determined. This has been going on for a while now and I was loosing my mind. I hope this can add another variable for people to check, and hopefully it helps someone else. What a great site.

sk7
09-30-10, 08:21 AM
Great news! I had also taken that one apart early on mine, took off the tape and checked all wires. Not the best spot for so many important wires and connectors! They were dirty and muddy but all ok. Good job u deserve a few cold ones!!!

wadman
10-20-10, 11:32 AM
bump. i am going to need to find this thread tonight or tomorrow to fix mine.

sk7
10-21-10, 04:37 PM
Good luck and keep us posted on ur results!

xidino
10-23-10, 10:56 PM
Hi, new member with the same problem. I read thru this post and got some idea to try to solve of not running compressor on my 05 escalade. I started by took of the relay, but i do not know which point to be sort to activate the compressor? There are 4 point; 30, 85, 86 and 87. which of those should be connected, is it 30 and 87?

sk7
10-24-10, 05:28 AM
Correct!

xidino
10-24-10, 06:09 AM
Jumped with a wire, socket number 30 with 87, the compressor did not start.
I jumped for only less than 5 second because the wire getting hot in my hand, cannot hold it.
Is it ok if the wire become hot?Should i tried any longer?
Thanks sk7 for ur reply.

sk7
10-24-10, 11:11 PM
Good thinking! If you are jumping the two correct wires (2 bigger ones), the compressor motor is short to ground or the assembly is jammed. You will need to remove the compressor assembly to further investigate.

xidino
10-25-10, 01:30 PM
Inspected the comp yesterday morning, the three tork bolt were loose, and the compressor is movable up and down.It must be when it was still running shaking a lot. Not remove it yet. As still had no time for now.

xidino
11-01-10, 08:41 AM
Removed the compressor today;
-Direct jump with 12v, comp. wont run.
-Disassemble the unit, the magnetic rotor chamber is filled with water, and rust.
It must be from the carwash when it was jack up wash.

-No is going to cleaned it.
-------------------------------------------

-The bearing seems to little bit loose.

SK7 might you have some suggestion, or analyse what could be the prognosa of the comp.What prt might be need to pay more attention.

xidino
11-01-10, 09:25 AM
Here is the image before cleaning.

sk7
11-02-10, 02:01 AM
Ur best bet would be to replace the assembly with an Arnotts'. But I would still try to revive this one (I'm cheap...)! If you can make the motor run again make sure to take a look at the exhaust solenoid. Corrosion must have severed the 2 wires in there. Using jumpers, test solenoid operation while the assembly is still off the truck via the round connector. If motor and solenoid are functionning, ur good to go!

xidino
11-04-10, 03:53 AM
Hurray,
Compressor is alive.
Now what...
Do i have to replace the drier?
The o ring for drier is broken.

What is the sensor attached to the drier for?
And what is the one attached to the compressor cilynder for?

sk7
11-04-10, 11:34 AM
Pm'd ya. Sensor on the dyer is a pressure reference, but the one you need to worry about now is the solenoid exhaust, at the compressor cylinder.

conardh
11-07-10, 07:55 PM
This is a great thread with a wealth of knowledge. My compressor quit running upon start up of the truck, I could jumper the relay contacts and the compressor would run. I removed the compressor and found the exhaust solenoid coil open. I believe the computer looks at the condition of that coil to give the compressor a start, since most every compressor likes to start unloaded when possible. A new one came from Arnotts the next day. I removed the old connector and bracket and mounted it to the new compressor. Spliced the 4 wires color for color. Arnotts also sends the rebuild kit for the dryer (step by step with pictures...god I love pictures) Rebuilt the dryer (old one had moisture and the guts were end of life) and reinstalled the unit. Started the truck and found the new unit was much less noisy than the old. ( Thanks to an enhanced design of the rubber mounts) Air ride works with no alarm. Great to see quality being built in the US. I'm glad this thread was here, I studied it a lot before spending about 200 for a new compressor........Thanks Guys

sk7
11-07-10, 08:52 PM
This is a great thread with a wealth of knowledge. My compressor quit running upon start up of the truck, I could jumper the relay contacts and the compressor would run. I removed the compressor and found the exhaust solenoid coil open. I believe the computer looks at the condition of that coil to give the compressor a start, since most every compressor likes to start unloaded when possible. A new one came from Arnotts the next day. I removed the old connector and bracket and mounted it to the new compressor. Spliced the 4 wires color for color. Arnotts also sends the rebuild kit for the dryer (step by step with pictures...god I love pictures) Rebuilt the dryer (old one had moisture and the guts were end of life) and reinstalled the unit. Started the truck and found the new unit was much less noisy than the old. ( Thanks to an enhanced design of the rubber mounts) Air ride works with no alarm. Great to see quality being built in the US. I'm glad this thread was here, I studied it a lot before spending about 200 for a new compressor........Thanks Guys

Thanxs for the update! You are correct about the function of the exhaust solenoid. I should have a look at the dryer on mine. I fixed the solenoid but didnt pay attention to that. I would not hesitate on an Arnott unit if catastrophic failure happens!

fitz13
11-17-10, 07:49 PM
ok, another new member of the forum here :) after spending much time readung through everyone's problems - and congrats to those who have found solutions to there's...I am still, as well as my dealer, dumb founded with my issue. My compressor was tested and works. Shocks and lines have no leaks. Truck turns on, within 30 sec compressor kicks on, rear lifts...i attach our trailer and rear end never auto levels out...ugh! Any thoughts?