That was supposed to say

I always go wakeboarding after work on Thursday.

sorry

 

I pulled a trailer with the truck this weekend.

And it did not solve the problem at all. I can pull fine while manually selecting the gears but tow haul will just start down shifting out of now where until it running close to 5200 rpms.

I guess I'll have to take it to a trans shop or set it on fire and roll it down a hill.

 

I don't know if you still have that problem with your TH, but it is a problem with some of gm's logic. It is called Shift Stabilization and according to gm that is what the trans is suppose to do. It is extremely annoying. I was having fits with it when I did me 6l80 swap. Finally the way I fixed it was reflashing the TCM with a new OS from a different VIN and then tuning the shift speeds.

 

Ok thanks I tried download the trans tune from a 2010 6.2 but that didn't help. Do you think I need to go newer than that????

 

It won't help to load a different from HP tuners. You need to load new OS from GM. You could do it through GM's SPS if you have a pass thru type tuning device (i.e. a MDI). Your problem isn't the tune it is the underlying OS.

 

could a dealership do this? All I have is HP tuner

 

Yes a dealer can do this, but my guess is unless you know either the service manager or the drivablilty tech they won't do it. Not that they can't but won't. It is worth a try, it is not hard at all, maybe 30 minutes of work. If you have a dealer the is really into the Chevrolet Performance, you would probably have a better chance. If you know someone with a MDI you could do it yourself pretty quickly. The other thing you need is the VIN of some other truck with the 6 speed, preferably the same year as yours. There was a for sure change in the OS in 2009, so you can't go older.

 

If you want pm me and I can walk you thru the process.

 

I just wanted to update this in case anybody else ran across this thread.

Problem solved.

It was the brake switch that was going bad and messing with the computer. It wasn't even throw a code either. I randomly ran across a Youtube video where a guy was describing the same problem and he replace the brake switch to fix the problem. I figured for 25 buck and 10 mins of time it was worth a shot.

Motohead911 thanks for your help but I went to 4 dealership to see if they would switch OS systems for the TCM and they all looked at me like I was crazy. So this was a last resort that worked out.