We are having the same issue with code P1089. It’s been to the dealer 5 times now for this same issue. I am beyond mad!! We were told by the dealership that a GMC engineer was going to be out to them to fix the truck. Instead they just had a call with them and chased another non issue. We picked it back up today after it being at the dealership for 6 weeks. Within 5 miles, the code came back on. Has anyone had those problem resolved? GMC is putting such a bad taste in my mouth over this. We’ve had to cancel trips since we need our truck and this has been going on for about 6 months on a truck we are still paying for.
