Not my truck, but my dad's truck. 06' Avalanche 2500. The service light for 4wd has been coming on and off for a week or so now. The 4wd on the truck is used about once a week, but not abused at all. I had it in 4hi the other day leaving a jobsite and it acted fine. Got home and the 4wd service light came on and it wouldn't engage into 4wd at all. I turned the truck off and then back on and it was fine. Any ideas?

-Jim

 

Two of the most common things are the pushbutton switch and the encoder motor sensor. The pushbutton was know for having problems in the cold solder joints for the connector. The encoder motor sensor would develop an open in the circuit. I had the light come on in my '06, I replaced the switch and that wasn't it. Then I did the encoder motor sensor and got it.

If he has the Auto 4WD pushbutton here is the pn-15136039
The encoder motor sensor pn-88962315
gmpartsdirect is where I got mine.

 

Thanks, I'll look further into it.

 

same problem except i replaced switch and encoder, whats next? any suggestions would really help cause im gett effin pissed! thanks guys