For 1990-2009 cars

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 Diagnosis 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 reprogramming procedure in Engine Controls.

• | The security indicator flashes.

• | No DTCs are set.

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