My first experience with an electronically-controlled automatic was with my '02 Dodge Caravan. When I changed transmission fluid and filter, using the specified Chrysler ATF+4 fluid, the trans lost its mind. When the electronics woke up to new operating parameters, the transmission started behaving badly: harsh, almost damaging 2-3 downshifts, flaring upshifts, etc. Sometimes when the lever was placed in Reverse position to back out of the garage, the trans did not engage at all. Had to take it to the dealer to re-program the controller (under warranty, the first time).
The second fluid change, quite some time later, resulted in similar behavior. Had to pay the dealer, that time, to re-program.
At 135k miles, instead of dropping the pan, I used a suction gun down the dipstick tube to draw out a gallon of old fluid, and re-filled with new ATF+4. This time, no problems, only a partial fluid change. I’m trying to keep this vehicle on the road for a long time, and it has been very reliable, except for the ridiculous, unacceptable behavior of the transmission electronics. I also have to wonder about the future with the '10 Ford Fusion.
Anyone have similar experience, or information/assistance to offer?
(Please, no comments about changing the fluid too often. I’ve worked with vehicles and industrial machinery for long enough to know that “maintenance-free” is not a real-world option).