I'm really confused... I have no sound when I put the car in reverse...

I also have the scosche in my camaro and the swc is weird. I can toggle up/down presets but nothing works with volume and the mute button does nothing. If I press the ONSTAR button on the wheel it mutes the radio..

Ugh

I dont think it makes a sound when it goes in reverse. Mines just goes right into the reverse mode with chime or anything but i can hear the audio of the source in the background.

I mean my radio mutes -

Feature... so that you are not distracted when backing up?  Just a guess.