I have an 06 CTS, and I had to change the battery, when a battery is disconnected or there is power loss to the vehicle, once you have a new battery in it, the radio has no power. I was told that it has to be reset by holding down or pushes some buttons on the stock radio.. Does anyone know how to do this, or what I have to press to reset the radio and get it powered back on?

 

I believe you need a security code but some of the shop manuals tell you the procedure. Can I be so bold as to suggest calling a radio shop if you want to stay clear of the dealer.