4 wheel drive not working-please help!!! [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: 4 wheel drive not working-please help!!!


sherri
11-26-2009, 06:37 PM
My service 4 wheel drive light went on in my 2004 Trailblazer and I took it to the local dealership. They scanned it and found code c0327-encoder circuit malfunction. They tested and found encoder motor failure. Bought new encoder motor from the local auto parts store and installed it. The service 4 wheel drive light went off but the 4 wheel drive is still not working. What else do I need to do?

the roadie
11-26-2009, 06:52 PM
A quick search of previous posts with 4WD system problems (my specialty) shows there are two questions I always ask:

1) Do you hear distinctive motor noises when changing modes?

a) There is a high pitched noise lasting about 2 seconds from the front axle actuator. This one ONLY happens when going from 2HI->A4WD and from A4WD ->2HI.

b) The encoder motor makes a lower pitched and shorter duration noise in EVERY mode transition. 2HI->A4WD, A4WD->4HI, and 4HI->4LO and the inverse of those three.

c) Going into and out of 4LO also makes a clunk, and can only happen if you're going <5 MPH and in neutral.

2) If it makes the proper motor noises and goes into 4HI mode, and you jack up and support the front end, and rotate the driver's wheel, does the passenger's wheel rotate backwards?

Other relevant questions:

3) What kind of functional test have you done that says 4WD isn't working?

4) Any other maintenance history?

5) How many miles?

6) Did you change the transfer case fluid every 50K as recommended in the Owner's Manual?

sherri
11-26-2009, 07:26 PM
There is no high pitch noise from the front axle actuator. The encoder motor does make the low pitch noise and going in and out of 4LO also makes a clunk. When the car is jacked up, the passenger wheel does not rotate backwards. I took the vehicle out and found out that it was spinning in the mud instead of driving right through it. The transfer case was replaced last year. We had a used one put in from a trailblazer with 30,000 miles on it. I have 110,000 miles on mine now. The transfer case fluid has been changed.

the roadie
11-27-2009, 03:25 PM
You could have a bad front axle actuator. They're available on Ebay all the time. It's odd that the TCCM doesn't detect that failure though, and light up the "Service 4WD" light. I'd take the actuator out and see if it works while suspended in the air. I posted a thread about rebuilding one that just had a grease build-up on a copper PC board stripe inside. It would move, but not to the end-points, when mechanically loaded down by the spring inside the actuator mechanical assembly. When in midair it worked perfectly.

But for yours to not make a noise is very unusual. Try resetting the TCCM by pulling underhood fuse #8 for 30 seconds, then putting it back. See if the system behavior changes.

Also check rear fuse block fuse #48, that only powers the front axle actuator and the NEUTRAL mode light. Does the NEUTRAL mode work as the Owner's Manual says it should, and its light come on when expected?

snaraLT
12-02-2010, 09:16 AM
You could have a bad front axle actuator. They're available on Ebay all the time. It's odd that the TCCM doesn't detect that failure though, and light up the "Service 4WD" light. I'd take the actuator out and see if it works while suspended in the air. I posted a thread about rebuilding one that just had a grease build-up on a copper PC board stripe inside. It would move, but not to the end-points, when mechanically loaded down by the spring inside the actuator mechanical assembly. When in midair it worked perfectly.

But for yours to not make a noise is very unusual. Try resetting the TCCM by pulling underhood fuse #8 for 30 seconds, then putting it back. See if the system behavior changes.

Also check rear fuse block fuse #48, that only powers the front axle actuator and the NEUTRAL mode light. Does the NEUTRAL mode work as the Owner's Manual says it should, and its light come on when expected?

A Big Thank You to The Roadie and Trailvoy! :thx

After our first Mi snow yesterday I found that when I flipped the switch to AWD or 4HI nothing happened. A quick search of the forum lead me to this thread, where I copied down the diagnostic steps above.
After "resetting" the TCCM by pulling fuse #8 for the 30 seconds and putting it back in, my AWD and 4HI & 4LO all are working perfectly:)

jchandler
12-02-2010, 09:35 AM
Wow! I bookmarked this thread for sure!!! :tiphat

the roadie
12-02-2010, 12:15 PM
After "resetting" the TCCM by pulling fuse #8 for the 30 seconds and putting it back in, my AWD and 4HI & 4LO all are working perfectly:)Thanks for the kind words. Be aware that 2002 TCCMs are notorious for failing slowly, and you may find someday that it's dead and the reset doesn't work and then you need a 2003+ TCCM to wake it up again.

wifestrailblzr
01-23-2011, 12:38 PM
Wow, thanks a bunch. I had my differential replaced last year. Since then, the four wheel drive wouldn't engage fully all the time. Mostly, it would only work in Automatic 4WD.

Read this thread, went outside and pulled the fuse. Viola! Works like new.

Thanks again.

Samson
02-13-2011, 02:39 PM
I have a 2002 Trailblazer EXT w/ 100k. I never had a problem with the truck's 4-wheel drive system until this winter. With the recent snow storms hitting the NE, I really needed it... During the 1st snow storm, the 4-wheel drive system worked great until the 4-wheel drive check light came on. The check light went away and never returned, but now when I flip the A4W and 4HI switch, it lights up but the system doesn't engage. It makes a whirling, grinding noise. 4Lo doesn't light up at all. Need help, any helpful suggestions or answers?

the roadie
02-13-2011, 03:56 PM
..when I flip the A4W and 4HI switch, it lights up but the system doesn't engage. It makes a whirling, grinding noise. WHAT lights up? The lamp on the mode you're trying to go INTO? or the one you're coming FROM? Describe exactly what you see for blinking and steady lights and hear for noises under the vehicle, as you change mode from 2HI to A4WD, and also from A4WD to 4HI.4Lo doesn't light up at all. Need help, any helpful suggestions or answers?Are you in NEUTRAL and rolling under 2 MPH or at a stop when you attempt 4LO? If so, as before, describe the lights and noises you hear. If not, check the Owner's Manual, since there's an interlock.

At 100K, you should be about to change your transfer case fluid for the second time. What's your maintenance history on the transfer case and differentials?

shygirl9643
04-19-2012, 11:40 AM
I have already had the acutator changed and 4 wheel drive still doesn't work. Any suggestions of what else could be wrong with it.

bitz
07-27-2012, 09:07 PM
Did you try the TCCM? Do the lights on the selector illuminate? look for some other TCCM threads is my suggestion.

pauln1
11-14-2013, 10:46 PM
The other day in light rain I pulled away quickly from a stop light and the rear wheels spun - nothing happening up front but stabiltrack active message appeared. Tried again getting onto highway lots of rear wheel spin zip up front. Dealer found three codes and scheduled appointment. Codes indicated bad TCCM so new one ordered and installed. New one threw even more codes and was deemed defective. Nice - really inspires confidence. It's pointless maintaining these things since the parts are of such low quality. See you in a couple weeks Chevy dealer to fix something else. I don't count the sporadic TPCM - I can see if the tires need air all by myself. Never again a GM. :mad:

SMT 59
11-15-2013, 02:47 PM
xxxxxx

USA-1
12-07-2013, 04:36 PM
Replaced the Actuator and the front axle disconnect. Can hear the front actuator and the transfer case motor working. Can feel the front wheel engage by spinning will jacked up, and wife moving the switch to 4wd. The front driveshaft also spins the front wheels when in 4wd. Try and move the switch to 4lo and service 4wd light comes on with no light over 4lo, remains at 4wd. Move the ignition key to off and switch to 2wd then turn the key back on makes the motors work and the light go off. My guess is the transfer case clutches are worn.

jamesjh420
12-09-2013, 02:16 AM
im having the same problem it will sound like its locked in then its not and i get down the road and it decides to lock in and ill eventually unlock just a hassle any ideas would be greatly apperciated

jamesjh420
12-09-2013, 03:41 PM
and i replaced the switch pulled the fuses light still wont come on for the indicator and now service 4wd light is on

rockridge03
01-15-2014, 10:58 PM
Hi,

The Service 4WD light is on. No noise of any kind coming from the Transfer Case selector. No lights appear. The Transfer Case selector lights are out.

I would greatly appreciate any suggestions!

Thank you

boatangler
01-19-2014, 06:25 PM
Thanks, I was having some issues with my 2002 Trailblazer, found this thread, tried what it said & it seems to be fixed, for now anyway.
Here's the story. I took a 30 min. trip, all was ok on the way there, after we got there & met family for lunch the trip home was strange, the selector light for 4LO was on even though it was in 2WD, & it was running poorly, it would start out from the light ok then bog down badly on the shift & sometimes would shift out of first way too soon. I pulled out fuse #8 for 30 seconds, put it back in & the 2WD light came on, took it out for a ride & it's shifting like it should & running strong.
I'm guessing the unit is starting to go bad ? We had it replaced once under warranty when the selector switch stopped working correctly when it was only about one year old, of course that was 11 years ago

Freek245
01-28-2014, 09:44 PM
A quick search of previous posts with 4WD system problems (my specialty) shows there are two questions I always ask:

1) Do you hear distinctive motor noises when changing modes?

a) There is a high pitched noise lasting about 2 seconds from the front axle actuator. This one ONLY happens when going from 2HI->A4WD and from A4WD ->2HI.

b) The encoder motor makes a lower pitched and shorter duration noise in EVERY mode transition. 2HI->A4WD, A4WD->4HI, and 4HI->4LO and the inverse of those three.

c) Going into and out of 4LO also makes a clunk, and can only happen if you're going <5 MPH and in neutral.

2) If it makes the proper motor noises and goes into 4HI mode, and you jack up and support the front end, and rotate the driver's wheel, does the passenger's wheel rotate backwards?

Other relevant questions:

3) What kind of functional test have you done that says 4WD isn't working?

4) Any other maintenance history?

5) How many miles?

6) Did you change the transfer case fluid every 50K as recommended in the Owner's Manual?

I have an 03 TB that i just picked up with 152,000 and the 4wd does not work, when i flip to AWD or 4wd the lights just blink while the 2wd light stays on steady and after about 10 seconds the service 4wd light comes on in the dash. Not sure of the service records with the transfercase oil, (was going to try changing that next).

But, i do hear the the encoder motor work as you described and the actuator work as you described when i select each of the positions on the switch. What i did was jacked up the front of the vehicle up and put the switch into 4wd i first attempted to turn the front driveshaft going to the front axle, i could not turn it which tells me that the encoder motor is working correctly and that the transfer case is going into 4wd.

Next, i turned the front wheel, nothing, so this told me that there was something wrong with the actuator. I removed the actuator and flipped the 4wd switch and the plunger on the actuator moves in and out.

Then i decided to check the 4wd disconnect, when i pushed on where the actuator sits it felt a little funny engaging but did go in. So i decided to take the 4wd disconnect out and inspect it. When i took the disconnect apart everything inside seemed pretty good, the fork and the gears where all in good shape, the grease seemed a little crappy, not to bad but i decided to clean it all out and pack it full of new grease and put it back together. When i put the disconnect back in the vehicle and pushed on the the plunger it was engaging fine.

So, i thought that maybe the 4wd actuator was worn and not moving the plunger all the way out, and from reading other forums that most of the time that was the problem with the 4wd on the TB. i bought a new actuator and installed it and guess what IT DOES THE SAME THIIIIING FML!!!

I also tried removing fuse #8 from the fuse panel in the engine compartment for a min. I also checked fuse #48 under the rear driver side seat and that was fine, but from what i could gather if that fuse was blown the 4wd switch would not work (which it does). i also read that the TCM needs to be reprogrammed possibly? im not sure what that does or is it that it needs to be re flashed or is that there is an update for it wich i need to go back to the dealer for.

What is the next step i should take in trying to trouble shoot this problem? i mean i dont think that it is a mechanical issue, but an electrical one, but thats just my guess who knows with this thing lol. If you or anyone could help that would be greatly appreciated, thanks.

ddgm
01-29-2014, 10:39 AM
Roadie and most of the other knowledgeable people left here and went to G M T Nation.com ( without the spaces between g, m, t & M)(long story) about 2 years ago. Much more help there.

rockridge03
01-29-2014, 02:14 PM
Thank you