Noticed a hard downshift from 3rd to 2nd, around 28 mph. Took to garage they coded it and reported a loss of prime from the coder. Replaced fluid and filter first, did not fix problem. Next replaced the solenoid, as there was heavy leakage from the casing. This fixed the leak and when coded again, the loss of prime message was gone! After this fix still having problems with a hard downshift. Thinking of taking to a tranny shop, will look into having the TCM software updated, (based on the posts above.
Question for the original poster, Why does the vehicle require a software update on the TCM? Is this something 1 can do on their own or does it require the factory computer to update? Thoughts? Thank you.
Down shifting hard when coming to a stop
My 2003 T&C Limited 3.8L V6 started down shifting from 4th to 3rd gear harshly on deceleration. This started out of the blue. It only has a hard shift from 4th to 3rd tho... NEED HELP!
trans was rebuilt at 110,000 and is now all of a sudden started downshifting while driving down the highway.