For 1990-2009 cars

### 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

Ignition ON, command the security LED output control ON and OFF with a scan tool. The security indicator should turn ON and OFF when changing between the commanded states.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the IPC.
2. Connect a test lamp between the control circuit terminal 14 and B+.
3. Command the security LED output control ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

4. If all circuits test normal, replace the IPC.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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