Just an idea... pick up a used radio from ebay or craigslist and then bring it to another dealer. I install stereos and remote starters and the dealers pull this nonsense all the time. I just picked up a 2013 Tahoe and asked the guy and he said as long as the wire harness is not cut or spliced into it will be fine. I would definately go to another dealer either way.
I had a 2002 trailblazer that did the same exact thing. Mirrors would never be where they were supposed to be. Asked the dealer about it and they said it was a software issue and for $80 they would fix it. Didn't want to give the stealership the $ so I dealt with it.
Another option would be call a dealer thats a few counties over and tell the service department what your truck is doing and see if they offer up any info like "yeah we've seen a couple vehicles do that before and we did "this" to fix it."
I had a 2002 trailblazer that did the same exact thing. Mirrors would never be where they were supposed to be. Asked the dealer about it and they said it was a software issue and for $80 they would fix it. Didn't want to give the stealership the $ so I dealt with it.
Another option would be call a dealer thats a few counties over and tell the service department what your truck is doing and see if they offer up any info like "yeah we've seen a couple vehicles do that before and we did "this" to fix it."
