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 components of the system are:

    • Dash integration module (DIM)
    • Door lock actuators
    • Door modules
    • Door lock cylinder disarm switch
    • Instrument panel cluster (IPC)
    • Rear integration module (RIM)
    • Remote Control Door Lock Receiver (RCDLR)
    • Rear compartment ajar 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 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 remote function actuator module 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 front door.
       - Press the UNLOCK button on the transmitter.
       - Insert a valid Pass Key III key into the ignition and switch to run position.
    • To disarm the CTD system in the armed mode:
       - Use the key to unlock the front door.
       - Press the UNLOCK button on the transmitter.
       - Insert a valid Pass Key III key into the ignition and switch to run position
    • To disarm the CTD system when activated (alarming mode).
       - Use the key to unlock the front door.
       - Press the UNLOCK button on the transmitter.
       - Insert a valid Pass Key III key into the ignition and switch to run 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 in the door lock assembly as one method to activate the alarm. The driver door module (DDM) monitors all door jamb switches via a discrete input or the simple bus interface (SBI) from the other three door modules. If the rear integration module (RIM) receives a class 2 message from the DDM that a door is open and the CTD system is armed, the RIM activates the alarm.

Door Lock Cylinder Disarm Switch

The CTD system uses the door lock cylinder disarm switch in the door lock assembly in order to disarm the CTD system. When the door lock cylinder is turned to the unlock position the switch grounds the disarm input to the door module.

Remote Control Door Lock Receiver (RCDLR)

The remote keyless entry (RKE) system is an internal function of the RCDLR. The RKE 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 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 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 five basic modes (disarmed, standby, delayed, armed, and alarm) for operating the CTD system. The different modes are described below.

  1. 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 line. (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 line.
  5. 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 line. Any forced entry activates the alarm mode.
  6. 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 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.

Rear Compartment Lid Ajar Switch

The CTD system uses the rear compartment lid ajar switch in the rear compartment lid latch assembly as one method to activate the alarm. The RIM monitors the rear compartment lid ajar switch via a discrete input. When the rear compartment lid is opened the ajar switch grounds the input to the RIM. When the CTD system is in the armed mode, the RIM activates the alarm.

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

Inputs

The RIM monitors the following inputs:

    • Driver and passenger door jamb switches, class 2 message from the Driver Door Module.
    • Driver and passenger power door lock/unlock switches, class 2 message from the Driver Door Module.
    • Door lock cylinder disarm switch, class 2 message from the Driver Door Module.
    • Transmitter LOCK/UNLOCK buttons, class 2 message from the Remote Control Door Lock Receiver (RCDLR)
    • Rear compartment lid ajar switch.

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