GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Security Indicator Control

2

1

1

--

1. Security Indicator Inoperative

2. Security Indicator ON At All Times

Circuit/System Description

The security indicator is controlled by the body control module (BCM) based on commands from the immobilizer system or the content theft deterrent (CTD) system. With the ignition OFF, the security indicator is commanded by the CTD system. With the ignition ON, the security indicator is commanded by the immobilizer system.

The security indicator is located in the instrument panel cluster (IPC) and is supplied B+ at all times. When the immobilizer or CTD system requests the indicator be commanded ON, the BCM grounds the security indicator control circuit, illuminating the indicator.

Reference Information

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Content Theft Deterrent (CTD) Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Arm the CTD system. The security indicator should illuminate and/or flash during the arming sequence.

Circuit/System Testing

  1. Ignition OFF, disconnect the X3 harness connector at the BCM.
  2. Ignition ON, verify the security indicator is not illuminated.
  3. If the security indicator is illuminated, test the control circuit terminal 7 for a short to ground. If the circuit tests normal, replace the IPC.
  4. Install a 10A fused jumper wire between the control circuit terminal 7 and ground. Verify the security indicator is illuminated.
  5. If the security indicator is not illuminated, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.
  6. If all circuits test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or IPC replacement, setup, and programming