I have the same issue with my 2015 Tahoe. I actually just drooped it off this afternoon for them to look at it. It cost $200 just to do a diagnostic?. I had other recalls so i had to bring it in anyway.. this has been going on for over a month. I guess i should have googled it and tried the battery trick. I’m not paying $1000 if that’s what it is. I’ll report back tomorrow when they tell me