GM Service Manual Online
For 1990-2009 cars only

When armed, the content theft deterrent system is designed to deter vehicle content theft by pulsing the horns and exterior lamps for approximately 30 seconds when an unauthorized vehicle entry is detected. However, the content theft deterrent system does not affect engine starting.

An unauthorized entry can be any of the following with the content theft deterrent system armed:

    • Unauthorized entry into the underhood area, if equipped with remote vehicle start.
    • Unauthorized entry into the rear compartment.
    • When any door is opened without first being unlocked using the vehicle key or using the UNLOCK command from a keyless entry transmitter.
    • After a battery reconnect, if the battery was disconnected with the content theft deterrent system armed.
    • If the battery is disconnected and a power sounder module is installed.
    • The vehicle is being lifted or jacked up.
    • A window being broken, a window is down, or someone reaching into the vehicle.

The components of the content theft deterrent system are:

    • Body Control Module
    • Remote Control Door Lock Receiver
    • Security Indicator
    • Door Ajar Switches
    • Driver Door Key Cylinder Switch
    • Rear Compartment Lid Ajar Switch
    • Hood Ajar Switch (if equipped)
    • Content Theft Sensor (if equipped)
    • Power Sounder Module or Alarm Siren (if equipped)
    • Glass Breakage Sensors (if equipped)

Arming the CTD System

Use the following procedure in order to arm the system:

  1. Place the shift lever in P (park).
  2. Turn OFF the ignition.
  3. Open any door.
  4. Important: The system is not armed if the doors are locked manually; the power door lock switch or remote keyless entry transmitter must be used to arm the content theft deterrent (CTD) system.

  5. Lock the doors with the power door lock switch or the LOCK button on the transmitter. The system is in standby mode and will not start the arming timer until all doors are closed.
  6. The system will begin the arm sequence immediately after the last door is closed. If the keyless entry transmitter is used the arm the system after the vehicle doors are closed, the arm sequence will begin as soon as the LOCK command is received by the transmitter.
  7. Double clicking the LOCK command on the keyless entry transmitter will bypass the delayed arming function and force the system to arm.
  8. If the vehicle is equipped with passive locks, the vehicle will start the arming sequence when a keyless entry transmitter is no longer detected.

Locking the Vehicle Without Arming the CTD System

Locking the vehicle may be accomplished without arming the content theft deterrent system. Use of the manual door locks or using the key to lock the doors will lock the vehicle, but will not arm the content theft deterrent system.

Disarming an Armed System/Silencing an Alarm

If system arming has been requested by the vehicle key, power door lock switch or the keyless entry transmitter, it must be disarmed.

Important: Disconnecting the battery or pulling fuses does not disable the arm mode, since the BCM stores the CTD mode status in memory.

    • To disarm the content theft deterrent system in standby mode, perform one of the following:
       - Press either power door unlock switch.
       - Use the vehicle key to unlock the driver door.
       - Press the UNLOCK button on the keyless entry transmitter.
       - Insert a valid key into the ignition and switch to the ON position.
       - If the vehicle is equipped with passive locks, the vehicle will disarm when a keyless entry transmitter is detected.
    • To disarm the content theft deterrent system in the armed mode (non-event) or when activated (during an alarm event):
       - Use the vehicle key to unlock the driver door.
       - Press the UNLOCK button on the keyless entry transmitter.
       - Insert a valid key into the ignition and switch to the ON position

CTD Circuit Description

The following is a description of each component used in the content theft deterrent system:

Body Control Module

The content theft deterrent system is an internal function of the body control module which utilizes serial data and various switch inputs information to perform content theft deterrent functions. When the body control module detects an unauthorized entry, it activates the horns and exterior lamps. The body control module has 4 basic modes (disarmed, standby, armed, and alarm) for operating the content theft deterrent system. The different modes are described below.

  1. The body control module has the content theft deterrent system in a disarmed mode until the following conditions are detected:
  2. • Ignition key turned to the OFF position.
    • Doors locked by either the power door lock switch or the LOCK button on the transmitter.
  3. The body control module enters the standby mode when the above conditions are detected. If a door was already opened when the arm mode was requested, the standby mode does not start the timer until the last door is closed.
  4. When the last door is closed, a 15 second timer is activated. Once the timer has expired, the body control module enters the armed mode. After this delay, any forced entry activates the alarm mode.
  5. When the body control module detects a forced entry, the body control module enters the alarm mode. The body control module activates the horns and exterior lamps for 30 seconds. This is followed by a three minute time-out with the horn no longer active. If no new intrusions are detected after the time-out, the horn is not active. The system must be disarmed or the intrusion condition removed after the time-out for the system to exit alarm mode.

Remote Control Door Lock Receiver

The keyless entry system can arm and disarm the content theft deterrent system. When the keyless entry module receives a door lock or unlock signal from the transmitter, the keyless entry module sends a message to the body control module via serial data to perform the appropriate arm/disarm functions.

Security Indicator

The security indicator is illuminated on the instrument panel cluster by the body control module for content theft deterrent, or theft deterrent module for immobilizer. The content theft deterrent system uses the security indicator to inform the driver of system status prior to arming. The security indicator on the instrument cluster is controlled by both the content theft deterrent system and the immobilizer system.

    • The content theft deterrent system, integral to the body control module, commands the instrument panel cluster to control the security indicator only when the ignition switch is OFF. The content theft deterrent system uses the indicator to identify system status.
    • The immobilizer system, integral to the theft deterrent module, commands the instrument panel cluster to control the security indicator only when the ignition switch is ON as a malfunction indicator. The immobilizer system is to deter vehicle theft. Refer to Immobilizer Description and Operation for more information on the immobilizer system.

Door Ajar Switches

The content theft deterrent system uses the door ajar switches as a status indicator to activate the alarm. The door ajar switches are monitored by the body control module via a discrete input from each door ajar switch. If the body control module receives a signal indicating a door is opened when the content theft deterrent system is armed, the body control module activates the alarm.

Driver Door Key Cylinder Switch

The content theft deterrent system uses the driver door cylinder switch as a means to disarm the content theft deterrent system. The body control module receives the status of the driver door cylinder switch based on a discrete input from the switch. When the driver door key cylinder is rotated the content theft deterrent system will immediately disarm.

Hood Ajar Switch

The content theft deterrent system uses the hood ajar switch as a status indicator to activate the alarm. The body control module monitors the hood ajar switch via a discrete input from the switch. If the body control module receives a signal indicating the hood has been opened when the content theft deterrent system is armed, the body control module activates the alarm.

Rear Compartment Lid Ajar Switch

The content theft deterrent system uses the rear compartment ajar switch as a status indicator to activate the alarm. The body control module monitors the rear compartment ajar switch via a discrete input from the switch. If the body control module receives a signal indicating the rear compartment has been opened when content theft deterrent system is armed, the body control module activates the alarm.

Content Theft Sensor (Intrusion/Inclination Sensor)

The content theft sensor is a dual sensor that incorporates the intrusion and inclination sensors. The intrusion/inclination sensor is monitored by the body control module. The intrusion sensor is a shock sensor which monitors forceful entry or movement within the vehicle. The inclination sensor monitors the parked angle of the vehicle. Instances where vehicle angle may change is during jacking up of the vehicle or towing of the vehicle. If the content theft deterrent is in the armed mode and vehicle intrusion or inclination is detected, content theft deterrent will enter the alarm mode.

Theft Deterrent Alarm Siren or Power Sounder

The theft deterrent alarm or power sounder alarm is used on some export vehicles. If the content theft deterrent System is in the alarm mode, the body control module will request the theft deterrent alarm ON.

Glass Breakage Sensor

The glass breakage sensors are shock sensors which monitors forceful entry or glass breaking through the rear side windows of the vehicle. If the content theft deterrent is in the armed mode and breakage of the rear side windows is detected, content theft deterrent will enter the alarm mode.

Inputs

The body control module monitors the following inputs for content theft deterrent:

    • The door ajar switches
    • Driver door cylinder switch
    • The keyless entry transmitter LOCK/UNLOCK buttons; a serial data message from the remote control door lock receiver
    • The immobilizer status--The body control module uses the immobilizer status for disarming the system or silencing an alarm when the correct vehicle key is used to start the vehicle
    • The rear compartment ajar switch
    • The hood ajar switch
    • The Inclination/Intrusion Sensor (if equipped)
    • The Glass Breakage Sensors (if equipped)

Outputs

The body control module controls the following for content theft deterrent:

    • The horn relay
    • The exterior lamps
    • The power sounder module (if equipped)
    • The alarm siren (if equipped)