Theft Deterrent Diagnostic System Check

WARNING: This page is about a different car, the 1999 Pontiac Grand Am and 1999 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition on. Connect scan tool to Data Link Connector (DLC). Attempt to communicate with BCM. If scan tool communicates with BCM, go to step 3 . If scan tool does not communicate with BCM, go to next step.
Perform DATA LINK CONNECTIONS DIAGNOSTIC SYSTEM CHECK . Repair as necessary. If communication with BCM can now be established, go to next step.
Select BODY FUNCTIONS from scan tool menu. Observe BCM DTCs. If any DTCs for BCM exist, go to BCM DTC DEFINITIONS under SELF-DIAGNOSTIC SYSTEM. If DTCs for BCM do not exist, go to next step.
Remove scan tool from DLC. Turn ignition to cranking position. If SECURITY indicator turns on and then off, go to step 6 . If SECURITY indicator does not turn on and then off, go to next step.
If SECURITY indicator stays on or flashes, go to THEFT DETERRENT DIAGNOSTIC INFORMATION . If SECURITY indicator does not stay on or flash, go to next step.
If any history DTCs exist, go to next step. If no history DTCs exist, go to step 8 .
Go to BCM DTC DEFINITIONS under SELF-DIAGNOSTIC SYSTEM for diagnosis and repair of history DTC.
If vehicle will start and run, system is okay. If vehicle will not start and run, go to TROUBLE SHOOTING - NO CODES - CARS article in ENGINE PERFORMANCE

THEFT DETERRENT DIAGNOSTIC INFORMATION

Symptom	Procedure
Multiple indicators are always on.	Check for serial data loss.
Scan tool does not communicate with BCM.	See DTC U1064: LOSS OF COMMUNICATIONS WITH BCM under DIAGNOSTIC TESTS.
Security Indicator Inoperative.	Replace Instrument Panel Cluster (IPC).
Security indicator is always on, BCM has been replaced and the engine starts.	Reprogram PCM. See COMPUTER RELEARN PROCEDURES article GENERAL INFORMATION.
Security indicator flashes with no DTCs set.	Replace Instrument Panel Cluster (IPC).