I've bought a 23 Sierra 1500 Denali in February of 24. Everything was great until April when the weather started getting warmer. Suddenly everyday my truck would sit in the parking lot at work in the sun and get hot I would come out to leave in the afternoon and have no remote start, no air conditioning, no power tailgate function and no rear sliding window power. The first time it happened there was a check engine light and message on the dash to service the 4wd system and another message about the inner tailgate being opened which is was not. Once the sun went down in the evening everything would work fine as if it never happened. We didn't have many warm days in April so it happened a few times more. Brought it to the dealership in May and it had been happening more and more. Service rep only had it for a day and said they think it might be the main fuse block under the hood so they are ordering one. Fast forward to June. It now happens every single day and no word on when the part will be in. I've tried some testing of my own and found that if the cab stays cooler like under 85 degrees it doesn't happen. This leads me to believe it is an issue inside the cab like a body control module or something that's disabling certain circuits and allowing them to be enabled once the temperature cools down almost like load shedding. Has anyone heard of anything like this? At this point I'm waiting months for a part that I'm almost certain isn't the issue and I'm just about ready to go get a Toyota instead.
