Seems like the head unit might be on its way out. From time to time my radio will adjust volume on its own going from high to low and vice versa. From my research and knowledge, some of the factory head units are problematic. I can't help you with your issue but would suggest upgrading with a nice aftermarket unit. You don't have to dig deep into your pockets to purchase a decent head unit. It all depends on how long youre willing to deal with the issue. Good luck!