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.
Average mileage: 131,518 (13,300–230,000)
Drive Trains affected: 2WD, 4WD, Automatic Transmission
100 people reported this problem
Getting SERVICE 4WD on cluster. All lights out sometimes on push button control. Bulb test passes. Has gone into 4WD LO mode by itself. Can't change drive mode. Problem and message will go away for weeks sometimes.
Gets stuck in 4 wheel drive and does not return to 2 wheel main driving position
When I start my 2005 GMC Yukon, it will often times, by stuck in 4WD and won't switch to 2WD when I push the 2WD button. I've changed the actuator, but it's still stuck in 4WD. I've already purchased the encoder ring, but, after watching an installation video on "YOU TUBE," it talks about RE-PROGRAMING the encoder ring. How in the heck is this a DIY project if I don't have the computer programing equipment?!!
service 4wd message on dash and no lights on selector switch
Yukon would switch itself into 4wd from 2wd.
My wife figured out how to turn off the ignition and get it back into 2wd again.
Glad to know that its the sensor that needs to be replaced.
it would switch into 4WD on it's own and I couldn't get it switched back to 2WD. It did this randomly. I took it in for repair...I had an extended warranty. They said it wasn't covered. Had to replace the Transfer Case control module sensor. I think it should be covered...nothing I could have done to prevent this.
intermittent "service 4wd" message resulting in total outage of 4wd and even involuntary shifting into 4wd Low.
upon starting, 4wd low is already engaged, difficult switching out of low. has happened twice.
Switched to 4wd hi and won't switch to 2wd or 4wd lo or 4wd auto and don't think the 4wd is working at all
Can't shift into 4 wheel drive without getting stuck in. 4 wheel drive
Service 4WD notice routinely reported on dash. Inability to change 2WD to 4WD (or back) particularly after extended running period. Periodic solution by turning ignition off then back on, but solution is unpredictable.
No lights on 4wd switch..seems to have power but put on a new switch and still nothing. 4WD does not work.
My Truck is stuck in 4WD Low. No lights on the buttons and can not shift to 2wd
Same as previous posters. Intermittently goes into 4-Lo. This is a safety hazard, and another thing for GM to be ashamed of about this particular vehicle, which is both the worst AND most expensive I've ever owned!
used to stick in 4 WD Now it wont go in 4 WD atm all
Service 4wd on dash switch lights out will not function stays in 2 wd in operation
Service 4 WD indicator flashes, then car has no power. Disconnected battery and vehicle rebooted. Have not taken for repair yet. Suspect sensor is bad.
It sounds like a grinding noise in my front end but most people said it's a C0327 sensor if you need that in your transfer casing will that make it make noise if its not fixed yet
My truck won't get into 4 wheel drive