Last week I had the dealership do the software update recall on my 2021 3.0 Duramax Silverado with 62k+ miles. I told them that for the couple of weeks prior, it would downshift really hard from 2nd to 1st. Also, going up a hill out of my neighborhood, the truck would act as if I was on and off the accelerator in 3rd and 4th. They had me come in this past Monday and I fully expected they wouldn't be able to replicate the issues and I'd be stuck with a $199 diagnostic. Wednesday they called saying it needs a new valve body. I was told a week for the part to come in, and then they'd replace it. Reading all of these posts, I have doubts about the week estimate is accurate. I was also told no loaners available and that they couldn't get me a rental because "Hertz is out of vehicles". There goes the weekend camping trip. Only a week into dealing with it and I'm already thinking about other trucks. Unfortunately, it seems like most vehicles these days suck in one way or another.
