THEFTLOCK® is designed to discourage theft of your vehicle's radio. It works by using a secret code to disable all radio functions whenever battery power is removed and the radio is placed in a different vehicle. This feature requires no user input to be activated. The radio is automatically armed when it is put into the vehicle for the first time.

When the ignition is turned off, the blinking red light indicates that THEFTLOCK® is armed.

If THEFTLOCK® is activated, the radio will not operate if stolen. The radio will display LOCKED and a red LED indicator light will come on above the key symbol to indicate a locked condition. If this occurs, the radio will need to be returned to your GM dealer.