Service 4WD Message May be Displayed on Chevrolet Avalanche 2500

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.

RepairPal Verified
Average mileage: 130,857 (95,000–180,000)
Drive Train affected: 4WD
4 model years affected: 2002, 2003, 2004, 2005
14 people reported this problem
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
Viewing 1 - 5 of 5 problem details
My 2002 Avalanche will not switch into 4wd! I bought it new and take great care of it! Is there a recall on this issue?
2004 Chevrolet Avalanche 2500 - 4WD 95,000 mi,
Repeated "service 4wd" light comes on. Unable to change transfer position. Dealer replaces sensor
2005 Chevrolet Avalanche 2500 - 4WD 108,000 mi,
4WD message came on and will not engage into 4WD>
2002 Chevrolet Avalanche 2500 - 4WD 140,000 mi,
Was raining hard and started up my truck and 4wd service light came on. will not turn off.
check 4wd light kept comping on and it would also shift very hard when buttons were pushed