Looking to the forum for ideas. I have an 07 Tahoe LT with 94k. Switching to "Auto" on the dial **** yields "Service 4WD" light on dash and it automatically jumps to 4HI. I took it to my Indy shop and they found 1 of the 3 wheel speed sensors were bad. Replaced, same issue. Indy shop recently updated transfer case software which seemed to work initially, but now same problem after the car rolls to 25mph+.
What parts should I be looking at now to replace/ repair? TC Module?
Thanks!

 

On my 2003 Burb I had a similar situation. I replaced the servo controller on my transfer case. A real nuisance to repair. The original servo controller was completely frozen with dirt and oxidation.