Power Door Locks (AU3)
Power door locks (RPO AU3) were optional on the Camaro beginning in 1975 and remained optional until 1981. It allowed you to lock or unlock the doors from a switch on either door.
Typical cost ranged from $56 (1975) to $93 (1980).
Wiring diagrams: 1973 | 1978
A solenoid is mounted to the bottom rear edge of the door. When this solenoid is energized it'll raise or lower the door lock.