Service 4wd

Wesley Brown · March 30, 2009

I'm currently having occassional problems with the 4WD not wanting to engage on my 2006 GMC 2500HD Duramax. Every now and again when I loose traction and go to select 4WD it just starts flashing SERVICE 4WD at me and won't go in. However, if I throw it in reverse, back up 2" and try it again it will usually go. Also if I shut the truck off and let it sit for a couple minutes it seems to reset itself and work as well.

I brought my truck down to the GM dealership and asked them about this problem, but all they could tell me is that they would need to scan it. They also did not feel that this would be covered under the powertrain warrenty.

Does anyone have any insight into this problem and to whether or not issues surrounding the 4WD should be covered under powertrain warrenty?

Wesley Brown · April 1, 2009

Anyone experienced anything similar to this?

hotbread597 · April 2, 2009

Yeah I have had the same problem, mine is a 2006 GMC Sierra 2500HD 6.0L Gas, I took mine in and they replaced the electronic module that engages the 4x4 on the front diff and they problem went away. It was covered under warranty, but mine was done at 50000km's so under the bumper to bumper? I am not sure if your truck is still in that category or not.