Quote Originally Posted by nonnieselman View Post
2004 Burb 8.1 Shifts_TCC.ctz

Just for the heck of it, give this a try and see if the TCC acts different.

I searched all my tunes and i don't see that OS. I know on the larger trucks with the 8.1L there are several tables that we cant get to.
On a friends Kodiak with a 8.1L the Throttle wouldn't go over 50% over a certain speed. Ended up finding the original guy that did the calibrations on those trucks for GM and sure enough after changing some stuff to the 2500HD Truck tunes it made all the difference.
I think you'd get a giggle out of my current tune - I ended up at very similar changes to the shift patterns that you have. 3-4 upshift in particular, the lines are almost on top of each other. I also didn't find anything else with this OS, but there is so little information about the 8.1 around. That's pretty interesting about the Kodiak - if I had a .bin I'm sure I could go crazy trying to find stuff in there, but I'm not sure I care enough to expend that kind of energy.

Is there something different in the engine OS section? It's telling me the checksum changed, but not giving me a visible parameter for it. I'm in the habit of checking tunes having bricked an ECM with someone else's tune on a different car in the past - nothing personal just being cautious before I go test it