GM Service Manual Online
For 1990-2009 cars only

Theft Deterrent Diagnostic Information

Symptom

Procedure

Multiple indicators light continuously.

Inspect for serial data loss. Refer to data link connector (DLC) Cell 50 in Data Link Communications.

The Scan Tool cannot communicate with the body control module (BCM).

Diagnose and repair the serial data loss. Refer to Scan Tool Does Not Communicate w/ BCM in Data Link Communications.

The security indicator does not light under any circumstances.

The LED indicators are not replaceable. Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

    • The security indicator is continually ON.
    • The BCM has been replaced.
    • The engine starts.

Reprogram the powertrain control module (PCM) in order to relearn the theft deterrent system password. Refer to Password Learn in Engine Controls.

    • The security indicator flashes.
    • No DTCs are set.

Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.