I have had my 2004 Duramax LLY approximately four and a half months. On three or four different occasions, when I started my truck and put it in reverse to back out of the garage, it would not move. It is summer weather, and this has only happened after sitting overnight. The first time it happened, I thought I had the emergency brake on, but it wasn't. Usually it will start moving within five seconds. My truck has about 4,000 miles, and the dealer could not find anything wrong. He also said that no codes were set. Any ideas?
Thanks, Scotty

Once, when I shifted from park to drive I got nothing. When I looked at the dash to make sure I was in drive it said "shift inhibitted" on my DIC. I shifted back to park and into drive again and all was well. It has never happened again and that was about two months ago. I mentioned it at the dealer and they checked the tranny for codes and got nothing.

maynard9089...exactly the same thing happened to me about 4 months ago..no codes and absolutely no hicups since, 10,000 miles later.

it happens to my occasionaly if I shift right after I start it and dont give the tranny a second to build pressure to the clutch packs

I think it is an electric glitch. I think maybe the TCM was a little slow reading engine rpm and gave you the "shift inhibited" because it was not sure if the rpm was too high for a shift into gear. I doubt that its drainback because they solved that problem.


mike

Just about every onther time I put it in reverse I have to wait until it engages. I am sure it is just charateristic of the Allison.

Gotta be, I have had the same thing happen.