View Full Version : 4WD does not engage
rolodex
03-05-2008, 02:58 PM
I have a 2002 TB LTZ, recently the selector switch for 4wd stopped working, the lights are off, I did not get a 4WD trouble light at instrument panel, the car is running perfectly well in 2wd. I replaced the selector switch for a new one but the lights are still out and nothing happens when I use it. I also disconected the battery for about 20 minutes and reconnected it to no avail
Taking it to the dealer is very dificult since I have the TB in Panama City, Panama, and I am not to sure of the quality of service I can get, also parts are 2 times as expensive there.
Can a defective TCCM cause this problem,
Can anyone, please, thell me if they have had a similar problem and what could be the cause of this, or any other ideas of what else I can do to check it.
I got the same thing. It's a transfer case module that's shot. Order one from parts4chevys.com for ~$186 + shipping. I'm in the process of doing it this week.
rolodex
03-06-2008, 02:32 PM
Thank you for your comments Jmal, could you tell me if once I have changed the TCCM (Transfer Case Control Module), can I drive the TB to the dealer to have it reprogrammed. Or does it come programmed already from the factory.
Doc Brown
03-06-2008, 03:14 PM
The dealer has to reprogram it. From what I've read its $50-$100 depending on the dealer. And the TTCM can have codes in its history without nessesaraly showing a light on the dash. So you may need to have a dealer at read run a scan on it.
Before you go that route, look at the sensor connectors on the transfer case. There are several TSBs that address issues with the indicator lights, Two in particular might interest you. One has to do with the actuator/encoder motor ($500 just for the part from a dealer!)(TSB 04-04-21-004), the other with two speed sensors (TSB #05-04-21-003B, and 06-04-21-001). Evidently the wire casing cracks and water gets in and corodes the wires and sensors. So some of this can be inspected visually. I wish I had known that before I dropped a grand on mine earlier this week.
Thank you for your comments Jmal, could you tell me if once I have changed the TCCM (Transfer Case Control Module), can I drive the TB to the dealer to have it reprogrammed. Or does it come programmed already from the factory.
My TCCM was a type that could not be reprogrammed (2002-03), hence it needed to be changed. Now I don't know if the replaced TCCM is a newer version that can be reprogrammed or if it's still the old model that only fits your TB. Check with your dealer, there's an open maintenance note from GM about it... (whatchamacallit...?)
Yup, the word I was looking for... maintenance note = TSB...
petevw
03-06-2008, 04:07 PM
I had the same problem back in Oct. The indicator lights went out one day, then the next day they came back on.
After this happened a few more times, the lights finally stayed off regardless what I did (disconnect battery, pull fuse, etc.) Then the service 4wd light came on.
At that point, I took it to the stealership, who had to replace the TCM to the tune of about (I think) about $275. It's worked perfectly ever since.
rolodex
03-12-2008, 08:29 PM
Thank you all for your advise, I convinced that the TCCM is the culprit. I just hope the deler in Panama can reprogram it.