GM Service Manual Online
For 1990-2009 cars only

The CTD system (when armed) 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 is opened without being unlocked by using the key to unlock either of the front doors or the UNLOCK command from a keyless entry transmitter.
    • Opening the rear compartment prior to disarming the CTD system.

The components of the system are:

    • Door jamb switches.
    • Body Control Module (BCM))
    • Front door lock switch.
    • Rear compartment courtesy lamp switch.

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 transmitter must be used to arm the CTD system.

  5. Lock the doors with any 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 arm within approximately 30 seconds from the time that the last door is closed. This delay is shown by the SECURITY indicator ON STEADY. When the indicator transitions to OFF, the system is armed.

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 been requested by the power door lock switch or the transmitter, 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.

    • To disarm the CTD system in standby mode (SECURITY indicator on or flashing and door(s) open):
       - Press either power door unlock switch.
       - Use the key to unlock either front door.
       - Press the UNLOCK button on the transmitter.
    • To disarm the CTD system in the armed mode:
       - Use the key to unlock driver front door.
       - Press the UNLOCK button on the transmitter.
    • To disarm the CTD system when activated (alarming mode).
       - Use the key to unlock driver front door.
       - Press the UNLOCK button on the transmitter.

Personalization

Refer to Personalization Description and Operation in Personalization.

CTD Circuit Description

The following is a description of each component used in the CTD system:

Door Jamb Switches

The CTD system uses the door jamb switches in the door lock assembly as one method to activate the alarm. The body control module (BCM) monitors all door jamb switches via a discrete input. The alarm mode activates when both of the following conditions are met:

    • The BCM detects any door is open.
    • The CTD system is in the armed mode.

Body Control Module (BCM)

The body control module (BCM) controls all the CTD system functions. When the BCM detects an unauthorized entry, the BCM applies ground to the following components:

    • The horn relay.
    • The park lamp relay.
    • the low beam relay.

The BCM applies ground once per second for approximately 3 minutes, or until a valid input to disarm the system is received by the BCM. The BCM may also arm and disarm the CTD system. When the BCM receives a door lock/unlock signal from the key fob transmitter. The BCM perform the appropriate door lock/unlock command. The BCM performs one of the following functions:

    • Locks the doors and enters the armed mode.
    • Unlocks the doors and enters the standby mode.

Front Door Lock Switch

The drivers front door lock cylinders is equipped with a switch in order to disarm the CTD system. When the lock cylinder is turned to the unlock position the switch grounds the disarm input to the BCM .

Rear Compartment Courtesy Lamp Switch

When the rear compartment lid is opened the rear compartment courtesy lamp switch grounds the descrete input to the BCM. If the rear compartment lid is opened without disarming the CTD system, the system will consider this a theft attempt and activate the alarm mode.

Important

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

Inputs

The Body Control Module (BCM) monitors the following inputs:

    • Door jamb switches.
    • Driver and passenger power door lock/unlock switches.
    • Front drivers door lock switch.
    • Rear compartment courtesy lamp switch.
    • Transmitter LOCK/UNLOCK buttons.

Outputs

The Body Control Module (BCM) commands the following:

    • The horn relay.
    • The low beam relay.
    • The park lamp relay.

Security Indicator Operation

The Content Theft Deterrent (CTD) System can command the instrument cluster to flash or illuminate the SECURITY indicator only when the ignition is in the OFF position. The security indicator is a status indicator for the CTD system. Under the following conditions the security indicator may be commanded to flash or illuminate on steady.

Security Indicator Flashes

The CTD system is in the standby mode, gear selector is in the park position, ignition key is turned to the off position and any door is open.

Security Indicator Illuminated ON Steady

The CTD system is in the arm pending mode, the standby mode criteria has been met, the power door lock command or keyless entry command has been received by the body control module (BCM).

Security Indicator Transitions to OFF

The CTD system is in the armed mode, the arm pending mode criteria has been met, all doors are closed. The security indicator will transition to OFF approximately 30 seconds after the last door is closed.