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.

### Circuit/System Description

The content theft deterrent (CTD) system is a software based system in which the body control module (BCM) actively monitors certain inputs to determine if unauthorized vehicle access is being attempted. Based on inputs such as the door ajar switches, the rear compartment ajar switch, and the hood ajar switch, the BCM determines whether a CTD alarm is warranted. If unauthorized access is being detected, the BCM will pulse the vehicle horn and flash the turn signals as a means of theft deterrence.

### 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

1. Individually open and close each vehicle door while observing the door ajar indicator/message. The indicator/message should accurately transition between the door ajar and door closed state when each door is opened and closed.

⇒ | If the door ajar indicator/message does not properly transition when each door is opened and closed, refer to Door Ajar Indicator Malfunction.

2. Completely lower the driver door window and close all vehicle doors.
3. Ignition OFF, arm the CTD system using the keyless entry system by pressing the transmitter LOCK button twice. Verify the scan tool CTD Status parameter displays Armed.

⇒ | If not the specified value, refer to Keyless Entry System Malfunction.

4. Without disarming the system, reach in through the open driver window, unlock and open the driver door. Verify the scan tool Content Theft Mode parameter displays False.

⇒ | If not the specified value, replace the BCM.

5. With the door open, verify the vehicle horn is pulsing and the exterior lamps are flashing.

⇒ | If the horn is not pulsing, refer to Horns Malfunction.

⇒ | If the exterior lights are not flashing, refer to Turn Signal Lamps and/or Indicators Malfunction.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup and programming