Service 4WD Message May be Displayed on Chevrolet Silverado 2500 HD

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: 158,363 (2,300–277,502)
Drive Train affected: 4WD
8 model years affected: 2001, 2002, 2003, 2004, more2005, 2007, 2008, 2013
27 people reported this problem
Viewing 1 - 13 of 13 problem details
PUSH BUTTON FOR FOUR HIGH AND THE LIGHT BLINKS AND SERVICE 4X4 CODE COMES UP.TRIED PUTTING IN FOUR LOW AND IT MADE A CLUNK AND COULD NOT GET OUT THEN AFTER TRING FOR A WHILE IT CAME OUT?
four wheel high will not engage front drive. If I put it in four wheel low it will engage. If I switch from four wheel low to four high it will stay in four wheel drive for a short time and pop out with a slight bang.
service 4WD light came on at 97654 as I pulled into my driveway turned pickup off and restarted and light stayed off. Then at 105136 service 4WD light came on again diving down the highway pulled off the highway onto shoulder turned pickup off and then restarted light stayed off but taking pickup to be serviced this week.
when i push the 4wd button it blinks a few times and does not engage 4wd.
Won't engage 4 wheel drive
Service 4x4 comes on for no apparent reason
bangs when engauging to four hi
information center displays service 4x4 changed 4x4 transfer case selector same issue service 4x4
service 4wd message came on. replaced position switch
2015 Silverado 2500 4WD service warning comes on for no apparent reason.
4×4 engaged but when i gave it gas it popped out of 4 wheel and service 4 wheel drive light came on.
Replaced 4WD electrical engage system one year ago and the problem has now returned. The cost was over $800.00 for this repair.
Push button for 4x4 and light comes on service 4x4 & will go in to 4x4 sometime then go out of 4x4