Transfer case control module on GMC Envoy

Average mileage: 141,000 (110,000–193,000)
Drive Train affected: 4WD
2 model years affected: 2002, 2004
4 people reported this problem
4 people shared problem details
Battery went dead in the Envoy one day. After replacing the battery the 4 wheel drive indicator light would not change with the selector and the 4 wheel drive light came on. After researching online I found that the engineers at GM forgot to set up the transfer control module with anything to save the memory, so basicly, it didn't know what to do. It also said you could take it to a dealer and they could reflash it for $100 and hope you never have battery problems again or locate a used one (2003 or newer because GM corrected their screw up after 2002 models). Make sure you research and get one that matches your 2002. Mine came from Ebay for $35 and was from a 2003 Trailblazer and it works great and I don't have to worry about the memory being gone if the battery goes.
2004 GMC Envoy120,000
my envoy goes into 4 wheel drive without you putting it into 4 wheel drive
2002 GMC Envoy- 4WD
Light stays on 2wheel drive at all times and brand-new switch no noise from the transmission
2002 GMC Envoy- 4WD193,000
Battery would hold charge. When it was swapped for another battery, the 4wd light came on and the indicator lights no longer illuminated. Went to the dealership to reprogram the module. After waiting 2.5 hrs, they said my car was ready. After paying, the light came on as soon as I got into my car. Told them and they tried to flash it again, but no luck. Now, they are saying I need a new transfer case control module. ~$400+tax. IDK how difficult it is to fix, but I may have to try.
Related Items:
This seems to have started a couple weeks ago, we noticed a winding type sound while driving do...
If you do not have the transfer control module will it cause problems
i've been fighting this problem for 10 weeks. the cooling fan will sound like a large blower at...
Help! I replaced the encoder switch as suggested by my GM dealer. I still have no 4 wheel drive...
I did the research on the Envoy door switch. The first thing I noticed was the number of plugs...

Related Content