heres my experiece as i work in a shop


drain and fill is not a bad thing--this flushing never drains the fluid in the torque converter


if you are using a machine to flush the atf, its a good idea to smell the current fluid on it, now if the fluid smells burnt and you see some metal particles on the dipstick, i dont suggest you change it as it will make your tranny slip and slide then you will get a car that shifts too early or too late.

its important to use the correct fluid type as well


for the one who have this tranny problem, if you think the problem is electrical, they mostly set a code. how do i know this, coz i work in a shop and i see these. i wouldnt suggest you changing anymore electrical part while trouble shoooting