Is my tranny slipping?it need to be

sgiangregorio · October 1, 2003

Vehicle: 2002 Tahoe Z71. Not sure exactly which tranny it has.

Every once and a while when I accelerate from a complete stop, the engine will begin to rev a bit and the truck will start to move slowly and then it will lightly "slam" into gear and get going. It's only happened 4 times since I got it (Aug 2002), but since I already have 25,000 miles, I want to have it dealt with prior to the warranty running out.

Any thoughts? Any TSBs on something like this? I was wondering if the onboard computer was just getting confused about what gear it was in, or that it wasn't downshifting fully when I came to a stop. Maybe a flash update?

Thanks for your thoughts.

nhkid28 · October 1, 2003

Try disconnecting the battery for about 15 min or so then hook it back up.

It will take a little while for the tranny to relearn your driving style after doing

this so don't worry if it shifts funny for 50-100 miles. If this doesnt work

then at least it didnt cost you anything. Give it a try.

Shaners · October 2, 2003

My truck did the same thing... I took it to the dealer, and luckily it did it for the service mgr when he moved the truck out back...

They re-flashed the computer, or installed updated programming and the truck has been fine for the last 18 months.

sgiangregorio · October 2, 2003

nhkid28, I've had the battery disconnected a few times; it's never changed. I don't think that's my answer, but I have used that trick in the past for other things. Thanks!

Shaners, that's what I was hoping for, a simple reprogram. Since it's done it since it was fairly new, I doubt its a bad tranny. Any TSBs that anyone knows of?

Shaners · October 2, 2003

Shaners, that's what I was hoping for, a simple reprogram. Since it's done it since it was fairly new, I doubt its a bad tranny. Any TSBs that anyone knows of?

I wish I could help you there... but all I know is my dealer looked into it, and found that the computer needed updated. I don't know if he found the info from a TSB, or if he called GM on it. He knew it was a problem because it acted up for him though, so he was obligated to fix it (none of the "could not duplicate" crap).

Good Luck!!!