on my 2020 denali, the only problem i have ever had is ebrake related. a few times ( 2-3 times and many months apart) have had all the messages: service this, service that...each time after deploying the ebrake and then trying to drive a short time later, within 5 mins. each time i disconnected the neg battery and everything cleared up and was back to normal. I belive its related to the automatic release of the ebrake when hitting gas. i now always release manually before driving, although i dont actually use the ebrake very often.