2018 Colorado Transmission problems

[Bryan1213]

I have a 2018 Chev Colorado V6 with the 8 speed in it. I had the shudder in the front end in which the dealer replaced the tranny fluid with thicker fluid to cause the torque converter not to slip. I had that done in Oct 2019(9800 miles). Ever since then the truck will hesitate shifting between 1&2 and 3&4. I just picked it up at the dealership after having their transmission tech run through it. No warning lights etc with it. It has 11500 miles now. The tech ran diagnostics, checked fluid and Tcm calibration. GM put a bulletin to “do transmission service fast learn procedure”, “do garage shift learn procedure”, and “do 1-2, 2-3 shift learn procedure. As I left, it hesitated again between 3&4. It only happens the first time it hits those gears and not again.. anyone have insight/thoughts/recommendations? Getting frustrated as I bought brand new.

[carloliveira]

The TCM is adaptive and learns the drivers throttle habits so you need to wait about 500 miles is what the service manual says before you can make a determination. The learning process takes about 500 miles in short is what I'm saying.....