The 4WD transfer case encoder motor position sensor or the selector switch may fail causing the service 4WD message to be displayed. Fault code(s) stored in the transfer case control module will be of assistance in determining the exact fault causing the message to be displayed.
Service 4WD Message May be Displayed on Chevrolet Silverado 2500
Average mileage: 111,416 (68,000–220,000)
Drive Trains affected: 4WD, Automatic Transmission
12 people reported this problem
4 people shared problem details
2004 Chevrolet Silverado 2500- 4WD70,000Visitor
my truck is a 2008 model it will not shift into 4 wheel drive and the light is flashing. the 4 wheel drive has rarely been used.
2000 Chevrolet Silverado 2500- 4WD70,500Visitor
Service 4 WD light comes on but it drives fine and Transmission was serviced
1999 Chevrolet Silverado 2500- 4WD132,000Visitor
I have a 2008. Light just came on.
replaced switch...light first came on at 100,000 miles.
Had O2 issue, bank2, sensor 1, replaced it, now there is No codes in OBD, but it is still slow...
4wd service light came on. The truck shift into 4hi all by itself. I change the 4wd selector sw...
One or more heater & AC (HVAC) air delivery and/or temperature mode door actuator may fail...
I've gotten stranded one too many times because my 2000 Chevy Silverado 2500 will not crank ove...
Won't shift out of park if key is on. Will shift if key is off and then can start in neutral .