Hi all, this is my first post on your forum. I bought a new 2021 Sierra 2500HD today. The truck had 31 miles on it when I purchased it. On my way home the truck now has 50 miles and a check engine light came on that won't go off. The dealer told me to open and close the door and try to restart truck a few times. This effort did not work. I will take the truck back to the dealer tomorrow. If any of you have any new information or how I can reset or fix without taking back to dealer I would appreciate it greatly. We love this truck and are hoping this is just something overlooked during the dealer prep.