i have a 05' Tahoe with 102'211 miles on it and have never had a single issue with it since I bought it new. It's been by far the best Truck I've ever owned. However, twice now on separate occasions the "check 4 wheel drive light" comes on. I hit the button on steering wheel and it then goes off. I had the fluid levels checked a week ago, and diff. Fluids changed a few years back. Anyway, I tried the 4WD in all 3 modes and it seems to work just fine, however I am concerned that there may be a upcoming problem and would like some advice as to what you would do or what you think I should try. Thanks in advance for your time and Expertise!
Respectfully,
D. Barth
audimanone1@verizon.net

 

The entire GMT800 GM line up is plauged by electronic 4x4 issues. My Tahoe has been no exception.

Normally it is one of three components.
1. Transfer case encoder motor ->
2. four wheel drive switch ->
3. transfer case control module -> 2003-2006 Chevrolet Tahoe Transfer Case Control Module - Transmission - Dorman 03-06 Tahoe Transfer Case Control Module - 3734-05263303 - PartsGeek


You can diagnose the switch through a simple series of tests with a multimeter. The encoder motor and switch are in my experience the most frequent offenders. All are pretty easy to replace with the switch and control module being the easiest.

Typically your 4x4 system becomes slowly more uncooperative. It will start thinking your transfer case is in a different position than it actually is and eventually will go into an electronic neutral position which will prevent you from switching the transfer case prevent it from damaging itself.

Hopefully that helps.