GM Service Manual Online
For 1990-2009 cars only

Important Preliminary Checks Before Starting

  1. Perform Diagnostic System Check - Theft Deterrent before using the Symptom Tables in order to verify that all of the following are true:
  2. • There are no DTCs set.
    • The control module(s) can communicate via the serial data link.
  3. Review the vehicle theft deterrent description and operation in order to familiarize yourself with the system functions. Refer to the following:
  4. •  Theft Systems Description and Operation
    •  Vehicle Theft Deterrent (VTD) Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the VTD 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 Security Indicator Inoperative in order to diagnose a SECURITY indicator malfunction.