GM Service Manual Online
For 1990-2009 cars only

Theft-Deterrent Feature Non-RDS Radios

THEFTLOCK® is designed to discourage theft of your vehicle's radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). If the radio is moved to a different vehicle, it does not operate and LOC displays.

With THEFTLOCK® activated, the radio does not operate if stolen.

Theft-Deterrent Feature RDS Radios

THEFTLOCK® is designed to discourage theft of your vehicle's radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). If the radio is moved to a different vehicle, it will not operate and LOCKED will appear on the display.

When the radio and vehicle are turned off and RAP is not active, the blinking red light indicates that THEFTLOCK® is armed.

With THEFTLOCK® activated, the radio will not operate if stolen.