GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Eldorado 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 Content Theft Deterrent (CTD) Operation

Content Theft Deterrent (CTD) System

When the content theft deterrent (CTD) system is armed, the system is designed in order to deter vehicle theft by pulsing the horns and the exterior lamps when an unauthorized vehicle entry is detected. The following list includes examples of an unauthorized entry:

    • Forced entry into the rear compartment
    • When any door is opened.

The body control module (PZM) controls all of the alarm functions. When the PZM has detected an authorized entry, the PZM applies ground to the following components:

    • The horn relays
    • The park lamp relays
    • The headlamp relays

The PZM applies ground once per second for approximately 3 minutes, or until a valid input to disarm is received.

The PZM has the following 5 basic modes for operating the CTD system:

  1. Disarmed
  2. Standby
  3. Delayed
  4. Armed
  5. Alarm

The different modes are described below.

The PZM has the CTD system in a disarmed mode until the following conditions are detected:

    • The ignition key is turned to the LOCK position.
    • Any door is opened.
    • The doors are locked by either the power door lock switch or the keyless entry transmitter (key fob).

The PZM detects these conditions and enters the standby mode. The PZM sends a class 2 message requesting the instrument cluster (IPC) to flash the security indicator. If all of the doors are closed and the key fob is used in order to lock the doors, the PZM goes directly to the delayed mode.

When the last door is closed, the PZM enters the delayed mode for 30 seconds. The time period may be substantially lower for vehicles with under 20 miles on the odometer. The PZM sends a class 2 message requesting the IPC to illuminate (stop flashing) the security indicator.

After 30 seconds, the PZM enters the armed mode. The PZM sends a class 2 message requesting the IPC to turn off the security indicator.

The PZM is now in the armed mode. Any forced entry activates the alarm mode.

If a door unlock request is received by the PZM during the arming sequence, the PZM will not arm the system. The PZM then sends a class 2 message requesting the IPC to turn off the security indicator. In order to arm the system at this point, repeat the arming sequence.

Security Indicator Operation

The PZM sends class 2 messages requesting the IPC to illuminate the SECURITY indicator. The IPC acknowledges these messages and then controls the indicator to the desired state.

Arming the System

Perform the following procedure in order to arm the system:

  1. Close all of the windows.
  2. Place the shift lever in the P (PARK) position.
  3. Turn the ignition switch to the LOCK position.
  4. Remove the key.
  5. Open any door.
  6. Lock the doors with the power door lock switch or the door lock button on the key fob.
  7. Close all of the doors.

    8. The system is now armed.

Locking the Vehicle Without Arming the System

Use one of the following procedures in order to lock the vehicle without arming the system:

Procedure A

  1. Lock the vehicle using the manual door lock knobs.
  2. Close all of the doors.

Procedure B

  1. Close all of the doors.
  2. Use the key in order to lock the door or the power door lock switch. Ensure that the doors are closed prior to locking.

Disarming the System

In the standby mode, the following conditions exist:

    • The security indicator flashes.
    • The doors are open.

In order to disarm a system in the standby mode, perform one of the following steps:

    • Press the power door lock switch to the UNLOCK position.
    • Press the door unlock button on the key fob.

In order to disarm a system in the delayed or armed mode, perform one of the following steps:

    • Use the key in order to unlock the left front door or the right front door.
    • Press the door unlock button on the key fob.

Deactivating the Alarm

In the alarm mode, the following conditions exist:

    • The horns sound intermittently.
    • The headlights flash.

In order to deactivate a system in the alarm mode, perform one of the following steps:

    • Use the key in order to unlock the left front door or the right front door.
    • Press the door unlock button on the key fob.

Alarm Mode Activation

Perform the following procedure in order to verify that the system activates the alarm mode:

  1. Turn off the following components:
    2. • The headlamps
    • The parking lamps
  2. Open a window.

    3. This action ensures that you will be able to open the door from the inside using the manual door lock knob.

  3. Place the system in the armed mode.
  4. Reach through the window and unlock the door using the manual door lock knob.
  5. Open the door.

The system enters the alarm mode. The following actions occur for approximately 3 minutes:

    • The horns sound intermittently.
    • The exterior lamps flash.

After 3 minutes, the system automatically shuts down.

Return System to Standby Mode

Perform the following procedure in order to verify that the system returns to the standby mode:

  1. Place the system in the armed mode.
  2. Use the key in order to unlock the door.
  3. Open the door.

The system does not enter the alarm mode. The security indicator flashes. This condition indicates that the system has entered the standby mode.

Ignition Disarm Function

Perform the following procedure in order to verify that the ignition disarm function operates:

  1. Place the system in the armed mode.
  2. Wait for the SECURITY indicator to turn off.

    3. This condition indicates that the system is armed.

  3. Cycle the ignition switch from OFF to ON, then back to OFF.
  4. Open the door.

The system does not enter the alarm mode. The SECURITY indicator flashes. This condition indicates that the system has entered the standby mode.