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.

The system consists of the following components:

    • The dash integration module (DIM)
    • The door lock actuators
    • The door modules
    • The instrument panel cluster (IPC)
    • The rear integration module (RIM)
    • Remote control door lock receiver (RCDLR)
    • Security indicator.

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

  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 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, since the rear integration module (RIM) stores the CTD mode status in memory.

    • 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 the driver front door.
       - Press the UNLOCK button on the transmitter.
       - Insert a valid PASS-KEY®III key into the ignition and switch to ON position.
    • To disarm the CTD system in the armed mode:
       - Use the key to unlock the driver front door.
       - Press the UNLOCK button on the transmitter.
       - Insert a valid PASS-KEY®III key into the ignition and switch to ON position
    • To disarm the CTD system when activated (alarming mode).
       - Use the key to unlock the driver front door.
       - Press the UNLOCK button on the transmitter.
       - Insert a valid PASS-KEY®III key into the ignition and switch to ON position.

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:

Dash Integration Module (DIM)

The dash integration module (DIM) controls the exterior lighting and the horn activation. When the RIM detects an unauthorized entry, the RIM sends a message via the serial data circuit to the DIM to activate the horns and exterior lamps. The DIM then grounds the appropriate relays to control the exterior lighting and horns.

Door Lock Actuators

The CTD system uses the door jamb switches that are internal to the door lock actuators as one method to activate the alarm. The door modules monitor the door jamb switch via a discrete input to the appropriate door module. When the door is open the door jamb switch grounds the door open input to the door module. The CTD system uses the door lock cylinder disarm switch that is internal to the driver door lock actuator to disarm an armed system. When the lock cylinder is turned to the unlock position the switch grounds the disarm input to the driver door module.

Door Modules

The drivers door module (DDM) communicates with the other door modules via the power door serial data circuit. The DDM sends a class 2 message to the RIM in order to perform the appropriate function.

Remote Control Door Lock Receiver (RCDLR)

The keyless entry system is an internal function of the remote control door lock receiver (RCDLR). The keyless entry system can arm and disarm the CTD system. When the RCDLR receives a door lock or unlock signal from the transmitter, the RCDLR sends a class 2 message to the rear integration module (RIM) in order to perform the appropriate arm/disarm functions.

Rear Integration Module (RIM)

The CTD system is an internal function of the rear integration module (RIM) which utilizes class 2 serial data circuit and various switch input information to perform CTD functions. When RIM detects an unauthorized entry, the RIM sends a message via the serial data circuit to the DIM to activate the horns and exterior lamps. The RIM has 5 basic modes (disarmed, standby, delayed, armed, and alarm) for operating the CTD system. The 5 modes transition from one step to the next in the following order:

  1. When in the disarmed mode, ignition is OFF and any door is open the RIM commands the instrument cluster to flash the SECURITY indicator via the class 2 serial data circuit. The RIM has the CTD system in a disarmed mode until the following conditions are detected:
  2. • Ignition key turned to the OFF position
    • Any door open
    • Doors locked by either the power door lock switch or the LOCK button on the transmitter
  3. The RIM enters the standby mode when the above conditions are detected. In standby mode the RIM commands the instrument cluster to illuminate the SECURITY indicator via the class 2 serial data circuit. If all the doors are closed and the LOCK button on the transmitter is used, the RIM enters the delayed mode.
  4. When the last door is closed, the RIM enters the delayed mode for 30 seconds. In delayed mode the RIM commands the instrument cluster to illuminate the SECURITY indicator via the class 2 serial data circuit.
  5. Important: The CTD system can be armed with the windows or sunroof open.

  6. After 30 seconds, the RIM enters the armed mode. In armed mode the RIM commands the instrument cluster to turn off the SECURITY indicator via the class 2 serial data circuit. Any forced entry activates the alarm mode.
  7. When the RIM detects a forced entry, the RIM enters the alarm mode. The RIM commands the DIM to activate the horn and exterior lamps for 30 seconds, via a class 2 message. This is followed by a 3 minute time-out of the horns, during the time-out period the horns are no longer active. If no new intrusions are detected during 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.

Security Indicator

The content theft deterrent (CTD) system uses the security indicator as a status indicator. The rear integration module (RIM) commands the instrument panel cluster (IPC) to illuminated the security indicator on steady or to flash the security indicator only when the ignition switch is in the off position via the class 2 serial data circuit. The security indicator will be requested to flash or to be illuminated on steady under the following conditions:

    • The RIM will command the IPC to flash the security indicator when either front door is open.
    • The RIM will command the IPC to illuminated the security indicator on steady when either front door is open and the doors are locked by the power door lock switch or a lock command from the keyless entry system.

Inputs

The RIM monitors the following inputs:

    • The door jamb switches, class 2 message from the driver door module (DDM).
    • The power door lock/unlock switches, class 2 message from the driver door module (DDM).
    • Driver door lock cylinder disarm switch, class 2 message from the driver door module (DDM).
    • Transmitter LOCK/UNLOCK buttons, class 2 message from the remote control door lock receiver (RCDLR).

Outputs

The RIM commands the DIM to control the following via a class 2 message:

    • The horn relay
    • The daytime running lamps
    • The park lamp relay