"TEMP LO" When Trying To Fast/Quick Learn a 6L80E Trans

2015 Chevrolet Silverado 2 wheel drive. Transmission is rebuilt, and all clearances on ALL clutch packs checked and corrected and all are within ATSG specs. New torque converter, Trans-go shift kit, new pump. Truck runs & shifts but it has a harsh 3-2 downshift, and a flare shift on 2-3 up, and other harsh downshifts as well.

I've attempted to use HP TUners to do the fast learn. I am logging the correct channels. It shows my temp as 189 deg. but then when I attempt the Fast learn it says TEMP LO.

I've *attempted* to use HP Tuners over the last 30 or so 6L's that I've built and out of those 30 only 3 times-Yes, a total of 3 out of 30-did it actually say "completed successfully". All the other 27 vehicles are gone-delivered to the customers-and running fine as none have come back. So, what is it with HP TUners and the fast learn functions not working????

Can someone recommend what I can do to get around this TEMP Lo situation on this current truck-or is there a BETTER piece of equipment available that is more reliable? I'll buy a GM Tech II if that is what I need. I run a transmission shop and need reliable tools. That's why we buy Snap On, Matco, and the like. Either I'm screwing something up, or the Fast Learn function within HP tuners is just jacked up. I recently replaced my lap top thinking that it was the problem-nope. Not the problem.

I also wish we could get working functions for the TCM. I can get the fast learn to work on my 8L90 but none of the other functions. I think the 8L90 functions are identical to the 6 speed TCM functions. Now I've heard that GM has removed a lot of these fast learn functions from the updated versions of GDS. I can confirm since I have a knockoff version of GDS and you can't do individual relearns only a fast learn procedure then and individual learn procedure for the "clutch apply" and "return springs" I would really like to be able to do the clean function also.

Also trying to get the fast learn to work and it seems to fail every time. Makes it to calibrating D, holds for 20 seconds and fails.

I can get the "Fast Learn" function to work fine, but not the "Clean" function on my 2018 Camaro SS A8