I am having the same issue. I have a 2021 AT4 with 600 miles on it. The dealership told me that the SD card needed to be replaced. So they are ordering me one in. At the same time I had a check engine light come on and on star told me it was throwing a P00C7 code. I had a 2019 AT4 and had nothing but trouble with it. The dealership told me that it was uncommon to have this many problems with this truck, that’s why I traded for a new one. Now I’m having problems with the new one already. I’m starting to loose confidence in GM.
