Petero

Have had 4 valve bodies on my 21 AT4. Last one an upgraded version. Had not had problem since but sold truck. It just did not feel the same. Wanted a 2026 but very worried of a repeat. Loved truck otherwise. Dealer made me pay for rental 2 out of 4 times. About 1500 bucks total. Contacted GMC. They said it’s a dealer decision.

I am not sure if this problem is related I had valve body failures 4 times before getting rid of truck. Each time the check engine light would come on. Sometimes staying on, most time going out within 50 miles. Sometimes I would get a loss of power, other times truck would not back up, another time it would not move. GMC is very dealer based and I could not talked to them directly. The 800 number person would say talk to dealer about warranty and suck. Dealer was not very good. In the end I was out 1500 dollars .