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:

    • When any door or the liftgate is opened without first being unlocked using the keyless entry transmitter
    • When the driver door is opened without being first unlocked using the driver door key cylinder
    • When the hood is opened, if equipped with remote vehicle start
    • After a battery reconnect, if the battery was disconnected with the CTD system armed

The components of the system are:

    • Rear electrical center (REC) module
    • Security indicator (if equipped)
    • Door ajar switches
    • Liftgate ajar switch
    • Driver door key cylinder switch
    • Hood ajar switch (if equipped)

Arming the CTD System

Important: The system is not armed if the doors are locked manually. The keyless entry transmitter must be used to arm the CTD system.

Use the following procedure in order to arm the system:

  1. Place the shift lever in PARK.
  2. Turn OFF the ignition.
  3. Exit the vehicle.
  4. Lock the doors using the LOCK button on the transmitter. The system is in standby mode and will not start the arming timer until all doors are closed.
  5. The system will begin the arm sequence immediately after the last door is closed. If the keyless entry transmitter is used to arm the system after the vehicle doors are closed, the arm sequence will begin as soon as the LOCK command has been sent.

Locking the Vehicle Without Arming the CTD System

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

Disarming an Armed System/Silencing an Alarm

If system arming has occurred, it must be disarmed.

Important: Using the power door unlock switch or manually unlocking the doors does not disable the CTD arm mode. Also, disconnecting the battery or pulling fuses does not disable the arm mode, since the REC stores the CTD mode status in memory.

To disarm the CTD system, perform one of the following:

    • 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 turn to the ON position.

CTD Component Description

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

REC Module

The CTD system is an internal function of the REC which utilizes serial data and various switch inputs to perform CTD functions. When the REC detects an unauthorized entry, it activates the horns and exterior lamps for 30 seconds. The system will re-arm immediately following an alarm event.

Security Indicator (if equipped)

The security indicator is illuminated by the instrument panel cluster (IPC) based on information, via serial data, from the REC for CTD or from the theft deterrent module for immobilizer. The CTD system uses the security indicator to inform the driver of system status prior to arming.

    • The CTD system controls the security indicator only when the ignition is OFF. The CTD system uses the indicator to identify system status.
    • The immobilizer system commands the IPC to control the security indicator only when the ignition switch is ON as a malfunction indicator. Refer to Immobilizer Description and Operation for more information on the immobilizer system.

Door Ajar Switches

The CTD system uses the door ajar switches as a status indicator to activate the alarm. The REC receives the status of the front door ajar switches based on a discrete input from each front door ajar switch. If the REC receives a discrete signal indicating a door is opened when the CTD system is armed, the REC activates the alarm.

Liftgate Ajar Switch (if equipped)

The liftgate ajar switch is located in the liftgate latch assembly and is a discrete input to the REC. The REC utilizes this input as a means to active the alarm if the liftgate is opened while the CTD system is armed.

Driver Door Cylinder Switch

The CTD system uses the driver door cylinder switch as a means to disarm the CTD system. When the driver door key cylinder is rotated the CTD system will immediately disarm.

Hood Ajar Switch (if equipped)

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

Inputs

The REC monitors the following inputs:

    • Door ajar switches
    • Driver door cylinder switch
    • Keyless entry transmitter LOCK/UNLOCK buttons
    • Immobilizer status--The REC uses the immobilizer status for disarming the system or silencing an alarm when the correct vehicle key is used to start the vehicle
    • Liftgate ajar switch
    • Hood ajar switch (if equipped)

Outputs

The REC controls the following :

    • The horn relay
    • The exterior lamps