I have a 2000 toyota sienna xle. I purchased it brand new from the dealer in 2000. So far it has all routine oil changes and mantinence. Lately the transmission has been jumping when shifting from 1st to second gear. Its an automatic and the car only has 64 thousand miles on it. I took it to a repair shop and they told me that the transmission was not the problem but the ecu. They did a transmission oil change hoping to find a bolt or something but there was nothing. It started happening when i installed a new battery. Does any one know or think that the ecu is the problem? they say it reset. please help. Iv‘e already paid 1000 dollars in repairs and diagnostics.
sometimes newer transmissions are computer controled and they keep a memory of how worn the transmission clutches are and they adjust the shift points accordingly for a soft shift. if you disconect the battery the computer can loose its memory, try driving it cold to hot a couple of clycles and see if it gets better.
If the problem started happening after replacing the battery, as you said, than yes, it is an ECU issue. Automatic Transmissions are highly efficient machines these days because they are controlled mostly by computers. Sounds like you may have had something short out when you replaced the battery and your transmission computer was fried in the process of.
