transmission jerks at steep roads ,only at low speeds,it began after I replaced the engine computer.
Could be a coincidence.
But I think your system “learns” how you use your car and adjusts the shift points, your car is still learning.
Or
Have you routinely serviced your transmission, changed fluid every 30,000 miles? A fluid change might help.
Actually I did have the transmission taken off , opened and check all components, than put back and tested ,mechanically there’s nothing wrong , no codes etc, it did improve but like you said the change of fluid might have had some effect , the recent change of engine computer was an afterthought, thank you anyway.