QuestionHello, I have a 2006 3.3L Sonata. When the car is first driven (when cold) the 1-2 shift is very abrupt, sort of 'bucking' the car. All other shifts are normal. This only does it on the first 1-2 shift, and only once. I can stop down the street, go again and it shifts smooth. The car has 83,000 miles on it, and fluid was drained at 60K, with genuine Hyundai SP111 installed. I understand that there is no filter in these tyranny's, but I am wondering why this does this? There has never been a CEL or anything like that. Any suggestions?
AnswerIt's possible that there's a problem with the fluid temperature sensor, but this would be likely to set a CEL, so it's a remote scenario.
If I were looking at this car and verified the condition and proper temperature sensor operation, I'd recommend resetting the transmission adaptive values and rechecking the next morning. If the problem remained, it's likely a problem inside the transmission itself, in which case transmission replacement would be called for.
Technical Service Bulletin 08-AT-003 describes how to diagnose this issue. If the shift time is more than a predetermined amount, it indicates the transmission control module should be replaced and the vehicle should be rechecked. I've never once seen a harsh shift issue repaired by replacing the control module; once this point was reached, the problem was always in the transmission itself, requiring replacement of the transmission.
