transfer case control module

Goat · September 13, 2005

I have a 02 Tahoe Z71 w/ AutoTrac. Service 4WD Light and dash switch lighting up like xmas tree. I replaced the switch - no help. Off to dealer. Tech diagnosis - bad xfer case control module. Fix will cost $539 if done by dealer. Since I've got some time before winter, I thought I would try to fix it myself and save some $$.

I pulled ATC fuse and now am 2WD only.

Need your help with following:

1. Where is xfer case CM located and can I remove it without specialty tools?

2. Anyone know a source for replacement CM or know anyone who repairs defective CMs.

3. If I find a replacement CM or get mine repaired, is re-programming required?

Any info or advice will be appreciated. Thanks guys.

Larry · September 13, 2005

Got to love that fancy push autocrap 4wd system…..

I see a lot of recommendations on this thread to replace control head switches when the light comes on but wonder how many times that one single piece really fails vs. the 4 other unreliable pieces of junk that also help make up the autocrap system. (Encode motor, TCCM, fuse and harness) TCCM in your case.

The TCCM is located at the lower left of the instrument panel above the fuse block. The TCCM is pretty much a dealer and salvage item only that I know of. You have to take off the IP bezel, 4wd control switch and dig back there to find the TCCM. No reprogramming is needed for a TCCM replacement. GM will pretty much grease you for this part. That is how they make money in service parts. Engineer a system that stinks and will fail then poke you for years of replacement parts.

Makes you wonder why so many people love the push button stuff when the manual transfercases are almost fool proof.