Well, yesterday after driving my 2015 Sierra here and there most of the day I parked to take the dog for her walk. 30 min later I started it up to cool it off and the radio was full blast, fortunately the dog was still outside. Turned down the volume and it would go right back up again. Radio continued to work with the key out and the door open, I pushed every button at least twice. Not sure what I did but finally got it off. Now with the dog in the truck all the time I'm afraid to turn the radio on at all. Who knows where/when it will happen again. I called the dealer and he wants to look to see if any codes are present. Other than that ?. My appointment is Friday I'll report back what the dealer did. Never in 35 years of driving have I ever witnessed something like this. Is this a 1 time thing, or has this happened to others multiple times. I'm mostly concerned for my dog..