my 4wd service light came on this morning but is now off could you tell me why?
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2004 GMC Sierra 2500 HD Question: service light
Answer #1Russ May 22, 2009, 09:23Master
The service 4wd light is like a "check engine" light for your 4wd system. When the light comes on a fault code will be set in the transfer case control module. This fault code can be read with a scan tool. The stored codes should help isolate the portion of the 4wd system that is causing the fault.
Answer #2Oakman January 14, 2010, 15:00Master
We just added this article last week, hopefully it will help you with your 4wd issue: http://repairpal.com/gm-4wd-warning-light-issues
Answer #3Visitor, May 08, 2010, 05:25
I had the same issue. There is a sensor located on the front diff. I disconnected and cleaned the connection. Quick fix...