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

329K views 438 replies 100 participants last post by  Submariner409 
#1 ·
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.
 
#330 ·
I read some of the tips all sound interesting. My service ride control or whatever it is pops up every time I turn the truck on. I don't have the service manuals for my 03esv, so if somebody can chime in and tell me where are all the fuses/relays I should be looking for. Truck stays at height at all times, does not drop at all(thanksgod). But would like to adress this issue. Thanks
 
#331 ·
Thanks all for the help on this thread. I was able to replace my compressor with an arnott through following all the tips. First checked the relay and to see if the wires were corroded with no luck. Picked up the arnott compressor kit at Advance Auto Parts for $193. Hooked it up and voila, compressor works again.

Couple questions though. The kit came with an air dryer rebuild kit. I did not do this as I had trouble trying to unscrew the dryer container. Is it important to replace this? My I have an '04 with 93k miles on it.

Also, is it necessary to have this calibrated or anything. I'm guessing the compressor is really just plug and play since it works but didn't know how it monitored the pressure in each shock.
 
#333 ·
I took the unit out and tested it. It is really easy to take out,Drivers side right behind the drivers tire. There is three bolts two on the outside (think13 mm) of frame rail. One is on the inside of rail through hole in rail by spare tire side. You dont way to take them all the way out just loosen and move the unit up and it slides out. After it is out you can see the wires to just. Also test the selenoid as that is what went out in mine. If I was in there I Hold also look to make sure my drier was not really wet. ( black tube on top of compressor)
 
#334 ·
Well, I just ordered my Arnott compressor with the rebuild kit. Question is.. does the cap of the drier just unscrew off the housing? thanks in advance... yea, it was the FRIGGIN' UNSEALED solenoid that was all corroded up and wires corroded in two.... also, open circuit on the solenoid wires themselves... That design is AWFUL ! ! Cadillac quality control engineers should have their ASS kicked. There wasn't even any sealant on the top plate of the solenoid. it appeared that water had been sitting in the housing.... idiots...
 
#335 ·
'49 Ford Coupe said:
Well, I just ordered my Arnott compressor with the rebuild kit. Question is.. does the cap of the drier just unscrew off the housing? thanks in advance... yea, it was the FRIGGIN' UNSEALED solenoid that was all corroded up and wires corroded in two.... also, open circuit on the solenoid wires themselves... That design is AWFUL ! ! Cadillac quality control engineers should have their ASS kicked. There wasn't even any sealant on the top plate of the solenoid. it appeared that water had been sitting in the housing.... idiots...
It ain't just caddie owners with this issue gmc and Chevy also use this same system although on certain models it is a option and not standred.
My advice is seal it up and see if it keeps water out.
I find it as a bad place to put the compressor anyway.
 
#336 ·
Aw hell, I know it's entirely across the GM truck line... and yes, it's a horrible place to put it... wonder if it's cheaper to run air tubes to the back or wires ? I already ordered my Arnott compressor..and surely (it appears) that the new compressor has it's own new solenoid...the entire old system is going to the dumpster...

OH, by the way. Does anybody know what the output pressure is on the compressor? Thinkin' of an invention to ZAP ******* drivers with a high pressure "squirt" system... ahahahaha...
 
#337 ·
'49 Ford Coupe said:
Aw hell, I know it's entirely across the GM truck line... and yes, it's a horrible place to put it... wonder if it's cheaper to run air tubes to the back or wires ? I already ordered my Arnott compressor..and surely (it appears) that the new compressor has it's own new solenoid...the entire old system is going to the dumpster...

OH, by the way. Does anybody know what the output pressure is on the compressor? Thinkin' of an invention to ZAP ******* drivers with a high pressure "squirt" system... ahahahaha...
You think like me with the squirt system but I don't know what the output of the compressor but I have thought of if it will work in a different spot besides behind the rear wheel I know my dad's hummer h2 has in the middle just behind the rear bumper which is where the spare tire is located on the escalade
I still can't figure out why they didn't protect the compressor better.
 
#338 ·
hi im new here today. i am having a problem with my 2002 EXT air ride. first i thought it was a bad compressor so i bought a new ARNOTT P-2204 from ebay and installed it and still does not turn on. i get power at compressor when i turn on the key but it is showing the black and red wires on the compressor are both hot with my test light. i can hear the solenoid click when i turn on the key. any ideas thanks
 
#339 ·
abel02ext said:
hi im new here today. i am having a problem with my 2002 EXT air ride. first i thought it was a bad compressor so i bought a new ARNOTT P-2204 from ebay and installed it and still does not turn on. i get power at compressor when i turn on the key but it is showing the black and red wires on the compressor are both hot with my test light. i can hear the solenoid click when i turn on the key. any ideas thanks
Sounds like something else and not the compressor, like a sensor or module.
 
#342 ·
I'm glad I'm not the only one having issues. I just replaced compressor and back shocks with Arnott ones. SRC light came on after about 5 minutes driving. The compressor turns on, stays on for about 10-15 seconds, then shuts off. The SRC light goes off when you first start up truck, but after driving for a few minutes comes back on. Where do I start??
 
#343 ·
bkman01 said:
I'm glad I'm not the only one having issues. I just replaced compressor and back shocks with Arnott ones. SRC light came on after about 5 minutes driving. The compressor turns on, stays on for about 10-15 seconds, then shuts off. The SRC light goes off when you first start up truck, but after driving for a few minutes comes back on. Where do I start??
Sounds like sensor
 
#347 ·
Hi, how do I need to oil compressor and how to seal it from water after I open it to fix? I got CRC message on my 2003 escalade esv, had mecanic read the code it was co660-exauste valve and co585-left rear solenoid. I remove compressor open valve cover and back panel , it was wery rusty both aluminum and steel and compressor humm but coudnt turn . I clean and oil and it start, I resolder exaust valve rusted out connection, test and it work. I disconnect and clean rusty electric connection on rear gas shock solenoid,test solenoid it has the same resistance as the other, assemble everything and start engine, compressor start CRC message is gone. I didnt test ride it yet.
 
#348 ·
Hey fellas...

Well, There are other threads on here that go through this whole "compressor problem". Here's the deal. IF you jumpered the two large wires in the relay base and the compressor runs, 99.99% of the time it's going to be the "bleed down" solenoid that is in the compressor housing. (Cadillac cost > $500 - forget THAT fix). As I understand, the 'puter monitors the circuit to that solenoid, and if the circuit becomes open (water in the solenoid (non-sealed), and/or if the TINY wires on the solenoid or solder joints break/burn up/corrode through, the computer won't allow the control relay to pull in. When you jumper the two large wires on the relay base, you are bypassing the compressors computer command. Get on line and buy the Arnott compressor kit for less than $200, which includes a rebuild kit for the dryer (new dessicant and pads), throw it back in there and you'll be good. The compressor housing is behind the driver's side rear wheel, held on with three bolts. You don't even have to take them all the way out. Just loosen them a few turns, and it will slide out/up to get it out. Pay attention to the routing of the pressure line and the wiring harness or take a picture. The pressure line disconnects by slipping the metal wire clip around and the tube comes right out. DON'T loose the little metal clip. I left it on the tube and after driving for about a week waiting on my new compressor, it fell off on the highway somewhere. I was able to fabricate one from a paper clip and it worked perfectly. The likelihood of having any other problem is slim and NONE. Good luck.

----------

Oh I forgot... just to be absolutely certain it is the bleed-down solenoid, when you take the compressor/solenoid housing out, pull the terminals, and ohm out the two wires going to the solenoid. You will probably find an open circuit.
 
#349 ·
replaced pump w arnott about 9 months ago. service ride control pops up about a week ago, it s cold here in the NW , but the big pig sits in the garage.

after the pump replacement, what the nex most likely candidate for failure?

very limited tow miles on this rig, air shock bags appear to be in good shape and functional

Ideas?:
 
#350 ·
jaswyoung said:
replaced pump w arnott about 9 months ago. service ride control pops up about a week ago, it s cold here in the NW , but the big pig sits in the garage.

after the pump replacement, what the nex most likely candidate for failure?

very limited tow miles on this rig, air shock bags appear to be in good shape and functional

Ideas?:
Possibly a sensor needs the codes pulled to be sure
 
#351 ·
I have a 2003 ESV, replaced the dead pump about a year ago with a new arnott pump...everything back to normal.

have never really towed anything and the shock bags look to be in good shape. pump only runs occasionally. a couple of weeks ago the service ride control message reappears and the pump doesn't seem to be firing up.

Checked both fuses, guess the next thing to do is jump the relay, Correct?

What else can go wrong with the system?
 
#352 ·
jaswyoung said:
I have a 2003 ESV, replaced the dead pump about a year ago with a new arnott pump...everything back to normal.

have never really towed anything and the shock bags look to be in good shape. pump only runs occasionally. a couple of weeks ago the service ride control message reappears and the pump doesn't seem to be firing up.

Checked both fuses, guess the next thing to do is jump the relay, Correct?

What else can go wrong with the system?
Jump the relay you may have a defective compressor they have a 1 year warranty on that
 
#353 ·
So... I am going to rebuild the solenoid in the compressor to get rid of the error message. In the meantime, I jumped the compressor and raised the truck about 1 inch. The top of back bumper was at 27"... Let it sit for about 6 hours and it has dropped 1/2"... is this normal or do I need to replace the shocks? They look great and the bags seem to be solid... The truck spent its whole life in southern TN and has 90k miles on it. Without a major leak, I doubt soapy spray would bubble..... Thoughts? I guess I can fix the valve and see what happens….

By the way, many thanks to all of you who have taken the time to post you findings on this tread. Your hard work will save me many hours of banging my head on the garage floor....
 
#354 ·
90limited said:
So... I am going to rebuild the solenoid in the compressor to get rid of the error message. In the meantime, I jumped the compressor and raised the truck about 1 inch. The top of back bumper was at 27"... Let it sit for about 6 hours and it has dropped 1/2"... is this normal or do I need to replace the shocks? They look great and the bags seem to be solid... The truck spent its whole life in southern TN and has 90k miles on it. Without a major leak, I doubt soapy spray would bubble..... Thoughts? I guess I can fix the valve and see what happens….

By the way, many thanks to all of you who have taken the time to post you findings on this tread. Your hard work will save me many hours of banging my head on the garage floor....
If it drops then there is a leak somewhere in the system try the soapy water and see if it is a shock bladder or a line as if it is the valve alone there would be no air in the shock bladders
FYI I have came up with a way to prevent future compressor issues with this vary problem(just have to build and test it first before I post anything about it)

The cause of the valve failure is water ingestion which messes up the valve solenoid and then causes the code which in turn makes the system go into passive mode and display the service ride control message in the drivers information screen
 
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