Beware, these GM radios have a security IC chip programmed with the VIN number as a theft deterrent. If you just plug it in the screen will show locked. There are You Tube videos on what it takes to program it. I was able to unsolder the IC chip from the broken radio and resolder it to the replacement unit. It worked but it's a small surface mount IC so it's not easy. The unit was in good condition and worked great once I transferred the IC chip.