: Service 4WD light came on



thehurtmac
03-20-13, 12:36 AM
It's snowing like a mofo here in N.H., leaving the gym i decided to romp around in "auto 4wd" in the parking lot in my 2000 escalade, my service 4wd light came on after a few minutes, so i stopped messing around and went and got gas. Turned it back on and never came back on during the 10 mile drive home. Any clues? I've only had it for maybe 600-700 miles, haven't done any regular maintenance on it yet.

the cadillac man
03-20-13, 12:55 AM
It's snowing like a mofo here in N.H., leaving the gym i decided to romp around in "auto 4wd" in the parking lot in my 2000 escalade, my service 4wd light came on after a few minutes, so i stopped messing around and went and got gas. Turned it back on and never came back on during the 10 mile drive home. Any clues? I've only had it for maybe 600-700 miles, haven't done any regular maintenance on it yet.

I would say its the switch (are the lights flashing or not doing a thing?)

thehurtmac
03-20-13, 03:35 AM
it just blinks when i try to put it in 4low, blinks then goes solid when i press the other 3 buttons, sometimes the light will disappear and come on randomly, confusing as hell and no clue how to fix it

the cadillac man
03-20-13, 11:56 AM
it just blinks when i try to put it in 4low, blinks then goes solid when i press the other 3 buttons, sometimes the light will disappear and come on randomly, confusing as hell and no clue how to fix it

Replace the switch I know as I had a friend who works at the collage I go to and his trucks transfer case went into neutral when his four wheel drive control switches failed he replaced the switch and didn't have a problem

Fox2boost
03-20-13, 10:27 PM
My money is on the shift solionid next to the transfer case did one on a surburban last year same symptom. Not cheap either. I wanna say the part was around 200. Six pack job.

thehurtmac
11-09-13, 01:21 PM
After 8 long months I finally got the new LM7 heart transplant. Its running rough because it hasnt been tuned yet and everything works except my 4wd...

I replaced the front solenoid and switch. All the lights on the switch blink once when I turn the key and that's it. I press and hold a button, nothing. I've yet to replace the rear diff solenoid but I have no clue why none if the lights come on.

Any clues?

the cadillac man
11-10-13, 12:04 AM
Replace the switch and all should be good

thehurtmac
11-10-13, 08:43 AM
Replace the switch and all should be good

I already replaced the switch and the front actuator. I stated this in my previous post.

the cadillac man
11-10-13, 10:49 AM
I already replaced the switch and the front actuator. I stated this in my previous post.

Is the fuse blown?

If not then it may be the control module that works the system

thehurtmac
11-10-13, 10:23 PM
Is the fuse blown?

If not then it may be the control module that works the system

I checked all the fuses. Pulled all 3 plugs to the T-case, they all have power or ground. It's getting tuned this week then I'll get a type 2 reader and figure it out. Sure is pissing me off though. The lights come on and go out when you turn on the ignition and that's it, and sometimes the lights don't even blink when you turn the key.

the cadillac man
11-10-13, 11:54 PM
I checked all the fuses. Pulled all 3 plugs to the T-case, they all have power or ground. It's getting tuned this week then I'll get a type 2 reader and figure it out. Sure is pissing me off though. The lights come on and go out when you turn on the ignition and that's it, and sometimes the lights don't even blink when you turn the key.

Check for voltage at the module
Its behind the headlight switch

thehurtmac
11-11-13, 12:13 AM
Does it say TCCM on it or anything that i will know what it is?

the cadillac man
11-11-13, 10:45 AM
Does it say TCCM on it or anything that i will know what it is?

It might never had to get one

thehurtmac
11-11-13, 12:37 PM
No clue what that means. Any 4x4 with the push button selection has a TCCM, automatic transfer case control module. It wouldnt work without one.

the cadillac man
11-11-13, 03:50 PM
No clue what that means. Any 4x4 with the push button selection has a TCCM, automatic transfer case control module. It wouldnt work without one.

Any of them with a transfer case has that module even mine does and its all wheel drive

thehurtmac
11-11-13, 04:27 PM
My buddy has a code reader that can read 4WD codes and he just told me the codes coming up are:

C0308 - motor AB circuit low
C0323 - t-case lock circuit low
C0327 - encoder circuit low

Time to do more research and call some dealerships.

the cadillac man
11-11-13, 06:37 PM
My buddy has a code reader that can read 4WD codes and he just told me the codes coming up are: C0308 - motor AB circuit low C0323 - t-case lock circuit low C0327 - encoder circuit low Time to do more research and call some dealerships.

I would check for loose ground wires before replacing any parts as those codes means a loose connection somewhere

I will look at my wiring diagrams and see where the ground wire is for the transfer case and its module and get back to you

thehurtmac
11-12-13, 07:55 PM
That would be awesome if it's just a ground and i don't have to replace the TCCM.

the cadillac man
11-13-13, 01:58 AM
That would be awesome if it's just a ground and i don't have to replace the TCCM.


It should be near the module

I will keep looking and see where it is at for sure

thehurtmac
11-13-13, 11:02 AM
Ok, is that the only external ground for the 4wd? or is there one by the t-case as well?

the cadillac man
11-13-13, 11:22 AM
Ok, is that the only external ground for the 4wd? or is there one by the t-case as well?

Yes it is on the frame I am thinking on the right side towards the front
I will check my service manual later and look to be sure

thehurtmac
11-14-13, 06:34 PM
Any luck?

the cadillac man
11-14-13, 10:42 PM
Any luck?

I was right it is on the right frame rail towards the front (most likely close to the transfer case)

thehurtmac
11-16-13, 04:17 PM
I paid $115 for a new TCCM and now my 4WD works. Sort of. The 2HI light comes on and stay on, it shifts into AUTO 4WD, i can hear the actuator. I put it in 4HI but hear nothing, but says it's in 4HI (solid light on the switch) but will not go into 4LO, the light just blinks. Any thoughts?

Code that is coming up is C0323 - transfer case lock circuit low. I think it might be a bad encoder motor. Not quite sure, but at least the damn thing works now.

the cadillac man
11-16-13, 06:31 PM
I paid $115 for a new TCCM and now my 4WD works. Sort of. The 2HI light comes on and stay on, it shifts into AUTO 4WD, i can hear the actuator. I put it in 4HI but hear nothing, but says it's in 4HI (solid light on the switch) but will not go into 4LO, the light just blinks. Any thoughts? Code that is coming up is C0323 - transfer case lock circuit low. I think it might be a bad encoder motor. Not quite sure, but at least the damn thing works now.

Did you check the ground wire??

thehurtmac
11-17-13, 07:19 PM
You never said exactly where the ground is, i need to know what both ends are attached to and the location of them. I got underneath it and looked for a ground coming off the rear t-case and saw nothing. Did the same thing to the front. There's no external ground from the t-cases to the frame.

the cadillac man
11-17-13, 08:01 PM
You never said exactly where the ground is, i need to know what both ends are attached to and the location of them. I got underneath it and looked for a ground coming off the rear t-case and saw nothing. Did the same thing to the front. There's no external ground from the t-cases to the frame.

Ok I will check in a bit and get back to you on the location of the ground

thehurtmac
11-19-13, 07:46 AM
Any luck?

the cadillac man
11-19-13, 11:46 AM
Any luck?

I haven't had time yet my mom had a stroke late Friday and I haven't been able to sit at my computer long enough to even look

I will try and look tonight if I have the time(I have been checking the forum on my iPhone using the owners app)

thehurtmac
11-19-13, 03:27 PM
Oh wow, I'm sorry man. I hope everything is ok.

the cadillac man
11-19-13, 07:42 PM
Oh wow, I'm sorry man. I hope everything is ok.

She's ok thankfully but will need rehab to help her regain the use of her left arm and leg

I have been busy today and will check in a bit

Is it the transfer case ground you need the location of?

If yes it should be on the right frame rail towards the front

thehurtmac
11-19-13, 09:01 PM
Glad she's doing ok, patience and time she will get better.

To be honest i dont know what ground i need to find, there are no external grounds on either transfer case.

the cadillac man
11-19-13, 09:05 PM
Glad she's doing ok, patience and time she will get better. To be honest i dont know what ground i need to find, there are no external grounds on either transfer case.

Thanks

I will be checking my service manual in a bit to see as I think there is a few grounds on the frame just have to see which one goes to what

thehurtmac
11-19-13, 10:59 PM
Alright thanks, if you have any pictures that would be 100 times more helpful than just a description, if possible. Thanks again.

the cadillac man
11-19-13, 11:46 PM
Alright thanks, if you have any pictures that would be 100 times more helpful than just a description, if possible. Thanks again.
I will try and snap a pic as soon as I can (been busy)

There is a ground point at the left front body mount that the module for the transfer case is on along with the fuel pump&sender the ebcm

I am going by my gm service manual

My MacBook Pro is on the fritz and I have been having a time getting it back working (been having to use a back up boot drive till I can get everything straightened out but still have access to my files

the cadillac man
11-20-13, 05:04 PM
Any updates?

thehurtmac
11-20-13, 07:07 PM
No, the truck is getting tuned and will be done Friday, I'm going to pick it up Friday or Saturday. I also still have no clue where that ground it. Sorry man.

the cadillac man
11-21-13, 12:34 AM
No, the truck is getting tuned and will be done Friday, I'm going to pick it up Friday or Saturday. I also still have no clue where that ground it. Sorry man.

If I have some free time(which is rare now for me) I will crawl under my truck and see where the ground location is and snap a pic and pm it to you so it will help

thehurtmac
11-21-13, 11:52 AM
My tuner just called, apparently my transmission isn't shifting automatically and is low on oil, my o2 sensors need to be replaced, my odometer isn't ran off the computer, my brakes are shot, and my water temp sensor doesn't work. Sweeeeeet. More money into this pit.

the cadillac man
11-21-13, 12:49 PM
My tuner just called, apparently my transmission isn't shifting automatically and is low on oil, my o2 sensors need to be replaced, my odometer isn't ran off the computer, my brakes are shot, and my water temp sensor doesn't work. Sweeeeeet. More money into this pit.

Tranny fluid is easy to add

The 02 sensors are at each end of the catylic convertors two per side
The temp sensor is also easy to replace

I will update when I can

thehurtmac
11-21-13, 06:25 PM
I know all of those are easy to replace. Just concerned about it not shifting automatically.

the cadillac man
11-21-13, 08:51 PM
I know all of those are easy to replace. Just concerned about it not shifting automatically.

Has the tranny fluid and filter been replaced?

thehurtmac
11-22-13, 08:34 AM
No but if it was low on tranny fluid is wouldn't shift at all. I talked ot my dad last night, hes a GM transmission mechanic of 20+ years.

the cadillac man
11-22-13, 01:30 PM
No but if it was low on tranny fluid is wouldn't shift at all. I talked ot my dad last night, hes a GM transmission mechanic of 20+ years.

It would shift at times and slip at times(no shifting)

thehurtmac
11-22-13, 04:13 PM
No no no. It's not shifting on it's own. In order to shift gears, I manually have to move the shifter to a different gear. It's another electrical problem. The transmission probably isn't getting power.

the cadillac man
11-22-13, 05:58 PM
No no no. It's not shifting on it's own. In order to shift gears, I manually have to move the shifter to a different gear. It's another electrical problem. The transmission probably isn't getting power.

That's the PCM causing that easy to replace its under the black cover to the left of the engine

Before you do that I will find the ground and tell you where its at so you can check it as most electrical issues are caused by a loose ground

thehurtmac
12-03-13, 04:02 PM
Transmission still won't shift and there's no codes coming up when scanned. The 4wd however has code C0323.