GM Service Manual Online
For 1990-2009 cars only

When armed, the content theft deterrent (CTD) 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 CTD system does not affect engine starting.

An unauthorized entry can be any of the following with the CTD system armed:

    • Unauthorized entry into the underhood area (if equipped).
    • 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.

The components of the system are:

    • Keyless entry module (remote control door lock receiver)
    • Door ajar switches
    • Body control module (BCM)
    • Driver door lock cylinder switch
    • Power door lock switches
    • Rear compartment lid ajar switch
    • Hood ajar switch (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 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.

Locking the Vehicle Without Arming the CTD System

Locking the vehicle may be accomplished without arming the content theft deterrent (CTD) system. Use of the manual door locks with the door closed will lock the vehicle, but will not arm the CTD system.

Disarming an Armed System/Silencing an Alarm

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

Important: Using the power door unlock switch does not disable the content theft deterrent (CTD) arm mode. Also, 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 CTD 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.
    • To disarm the CTD 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 (CTD) system:

Keyless Entry Module (Remote Control Door Lock Receiver)

The keyless entry system can arm and disarm the CTD 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 BCM via serial data to perform the appropriate arm/disarm functions.

Door Ajar Switches

The CTD system uses the door ajar switches in the door latch assemblies as one method to activate the alarm. The BCM monitors all door ajar switches via a discrete input from each door ajar switch. If the BCM receives a signal from a door ajar switch when the CTD system is armed, the BCM activates the alarm.

Body Control Module (BCM)

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

  1. The BCM has the CTD 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 BCM 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 BCM enters the armed mode. After this delay, any forced entry activates the alarm mode.
  5. When the BCM detects a forced entry, the BCM enters the alarm mode. The BCM 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.

Front Door Lock Cylinder Switch

The door lock cylinder switch located in the driver door and is a discrete input to the BCM. The BCM utilizes this input to disarm the CTD system. Inserting a key and turning to the unlock position will disarm the CTD system.

Power Door Lock Switches

The power door lock switches are used to either arm the CTD system at any time, or disarm the system if it is still in standby (not during an event). Pressing the lock position will cause the CTD to arm after all doors are closed, while pressing unlock will disarm the CTD if is in standby.

Hood Ajar Switch

The hood ajar switch (if equipped) is located in the hood latch assembly and is a discrete input to the BCM. The BCM utilizes this input as a means to active the alarm if the vehicle hood is opened while CTD is armed.

Rear Compartment Lid Ajar Switch

The rear compartment lid ajar switch is located in the rear compartment lid latch assembly and is a discrete input to the BCM. The BCM utilizes this input as a means to active the alarm if the rear compartment is opened while CTD is armed.

Important: The CTD system can be armed with the windows or sunroof open.

Inputs

The BCM monitors the following inputs:

    • Driver and passenger door ajar switches
    • Driver and passenger power door lock/unlock switches
    • Front door lock cylinder disarm switch
    • Hood ajar switch (if equipped)
    • Rear compartment lid ajar switch
    • Transmitter LOCK/UNLOCK buttons, a serial data from the remote keyless entry (RKE) module.

Outputs

The BCM controls the following:

    • The horn relay
    • The exterior lights.