ATF change out

[vtl]

Transmission has around 8 qt total capacity, about 3-3.5 quarts are in sump. You drain that and replace the fluid. Drive some miles/days/months, repeat. You can't replace 100% of ATF, it's physically impossible. Unless you wash like 40-50 quarts through the transmission to lower the old fluid contents to negligible.

[xHeart]

Transmission has around 8 qt total capacity, about 3-3.5 quarts are in sump. You drain that and replace the fluid. Drive some miles/days/months, repeat. You can't replace 100% of ATF, it's physically impossible. Unless you wash like 40-50 quarts through the transmission to lower the old fluid contents to negligible.

+1
The simple D&F method works best. This repeat eliminates the need for resetting fluid counter via VIDA. It worked for me. CN90 recommends do it with every other oil change to keep the ATF fluid relatively fresh.

[vtl]

This repeat eliminates the need for resetting fluid counter via VIDA.

You don't have to do that. I never reset the counter. The counter is incremented when ATF temperature exceeded 300F and keeps there for 3 minutes. When the counter reaches some value, the transmission changes its shifting strategy to keep torque converter locked whenever possible. I'd say, if that happened with your transmission - look for a replacement, yours is cooked. Good thing it's virtually never happens while driving normally, without hauling something heavy on highway on a hot day, etc.

What you may want to do is turning on transmission adaptation in the morning following fluid change and drive normally to work or around the town. That will quickly cure small shifting imperfections that may arise after the ATF has been changed, even partially, because the fluid has slightly different properties now and the TCM has to learn how to shift properly with that fluid.

Or just give it a few days, it will learn on its own. The important part is to keep refreshing ATF routinely