GM Service Manual Online
For 1990-2009 cars only

Important: The following steps must be completed before using the symptom tables.

Perform Diagnostic System Check - Theft Deterrent before using the Symptom Tables in order to verify that all of the following are true:

    • There are no DTCs set.
    • The control module(s) is operating properly.

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the Theft Deterrent System. Refer to Checking Aftermarket Accessories in Wiring Systems.
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

SECURITY Indicator Always On or Flashing

SECURITY Message Inoperative