So my 2012 Grand Sport worked flawlessly with the pin and USB hookup. Never missed a beat except when it heated up in the console. So we figured the 2015 would work the same…. wrong. All the problems you have listed here have happened.
I called GM and really go nowhere except to try different cables and different USB hookups. They advised a service appointment. So I looked up supported music formats and found that some of my files were not in a supported format many where Apple Lossless and I assume that when the player hits those it is shutting down.
So I started the car, plugged in the iPod and waited until the music indexed. After that it all seemed to work OK so far.
