What does service 4WD mean on a GMC Sierra?
Problem Description 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.
What does service 4WD message mean?
The “Service 4WD System” message indicates a problem with the 4WD system that should be properly diagnosed and repaired. When the ignition key is turned from OFF-RUN-START and is released back to the RUN position after the vehicle starts, the 4WD warning light should go on for 1 to 2 seconds and then go out.
What is the GM service 4 wheel drive message?
GM has issued a service bulletin # 09-04-21-001 to address a Service 4 Wheel Drive Message condition on the vehicles listed below. In addition to the Service 4 Wheel Drive Message, you may also have a C0387 or a C0569 trouble code stored.
What is the GM 4 wheel drive Bulletin?
GM has issued a service bulletin # 09-04-21-001 to address a Service 4 Wheel Drive Message condition on the vehicles listed below. In addition to the Service 4 Wheel Drive Message, you may also have a C0387 or a C0569 trouble code stored. 2007–2009 Chevrolet Avalanche, Silverado, Silverado Hybrid, Suburban, Tahoe, Tahoe Hybrid
What happens when service 4 wheel drive trouble codes are stored?
When the trouble codes are stored and the Service 4 Wheel Drive Message is displayed, the transfer case is inoperative for the rest of that particular key cycle. It will test again and reset the message on the next key cycle if the problem hasn’t been fixed. The codes may be stored with or without you requesting a transfer case shift.
What does it mean when your truck says service 4WD?
If the “SERVICE 4WD” message is lit as soon as you start the vehicle, that probably indicates a constant wiring or part fault and the Transfer Case Control Module is noticing that fault as soon as it is energized when the truck is turned on.