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 GMC Yukon
Average mileage: 111,750 (70,000–150,000)
Drive Train affected: 4WD
16 people reported this problem
2016 GMC Yukon - 4WD
With less then 2000 miles on my 2016 the truck is in the shop for the second time with the "service 4wheel drive light on". The first time was with only 900 miles. Currently in the shop now waiting on parts.
2005 GMC Yukon - 4WD 70,000 mi, Visitor
automatically switches from 2hi to auto4 to 4hi etc. turn car off, restart, reposition sensor button to 2hi
2002 GMC Yukon - 4WD 90,000 mi, Visitor
have replaced parts front axle 2times transfer case encoder buttons transfer was out and checked out by a award winning GM tec at dealer . No codes front end locks in encoder goes in In 2wheel front drive shaft turns easy. In auto vary little pressure cane turn it In 4 wheel the drive shaft can still be turned . This has been going on now for years . Encoders modulators buttons even the transfer. Case apart more then I can remember I have checked fuses replaced every control part for the 4 x 4 I anyone can tell me what to do ?? please it's not any part replacement
2002 GMC Yukon - 4WD 100,000 mi, Visitor
Light comes on when driving. Sometimes it stays on sometimes it goes out.