I'm having a bit of an issue with the 6L80E in my 2008 Yukon Denali. It is a fairly fresh build with all new soft parts including TEHCM and Sonnax valve body. I have attached the tune file and my stock file for reference. Basically it seems to be learning to flare the shift into third after driving the vehicle "normally". Acceleration under 80% calculated load and 3500 rpm results in a good 2-3 upshift. Above that and it will flare a little on the upshift. Sometimes feeling a little slip-bump like one clutch is coming off and another coming on. This happens 3-4 times, then the TEHCM learns the error and compensates for it, and it will shift good until I put a few miles on it at low to moderate load. Then the cycle repeats. Would someone more knowledgeable than myself be able to take a look at my files and see if there is anything I can do to minimize this issue? Thank you in advance.
Denali New TEHCM14.hpt
Denali Original Backup.hpt