2008 6L80E 3rd gear learned shift flare

[jimtruett]

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

[04silverado6.0]

I had success adding 20 kpa to the offgoing pressure preset tables. Add 20-30 kpa until the flare is gone.

[jimtruett]

I had success adding 20 kpa to the offgoing pressure preset tables. Add 20-30 kpa until the flare is gone.

Thank you for the assistance. I tried that, and no real change was realized.

I ended up adding to the 2-3 maximum adapt volume, and added a little to the #1 and #2 oncoming pressure presets for the 2-3 shift. This plus a couple other minot tweaks has it shifting much better, and after over 150 miles it has not started the "learned" flare again. Tune file attached in case anyone comes across this and has similar problems.

Denali New TEHCM15.hpt