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.

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