Hi, I have a 2017 chevy impala with 75k miles on it. The transmission has a delayed shift between 2nd and 3rd gear. It gets worse the more the cars driven 0-30 min don't really feel it 30 min-1 hr starts to happen after 1 hr happens 75 percent of the time. It gets a lot worse after you slow from highway speeds then accelerate. Transmission fluid level is full. The transmission valve body was replaced but didn't fix it. What could it be.
it needs to be diagnosed by a good transmission shop scan tools that can monitor clutch applications, line pressures etvc.
Has the car been scanned with a dealer-level scan tool for any codes related to the transmission?
I've given it to the dealer 3 times but they keep saying they can't find anything wrong. I'm going to go to an independent shop.