GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Envoy - 4WD 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 Content Theft Deterrent (CTD) Circuit Description

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.

    3. Ensure that the doors are closed prior to locking the doors.

Disarming the System

In the arm initiated mode, the following conditions are true:

    • The security indicator is ON.
    • The doors are open.

In order to disarm a system in the arm initiated 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 arm delay or the 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 are true:

    • The horns sound intermittently.
    • The headlights and the parklamps flash ON and OFF.

In order to deactivate a system in the alarm mode, one of the following actions must occur:

    • The key is used in order to unlock the left front door or the right front door.
    • The door unlock button on the key fob is pressed.
    • The vehicle control module (VCM)/powertrain control module (PCM) receives a valid Passlock ignition key rotation.

Alarm State Activation

Perform the following procedures in order to verify that the system activates the alarm state:

  1. Open a window.

    2. Opening the window ensures that you will be able to open the door from the inside using the manual door lock knob.

  2. Place the system in the armed state.
  3. Reach through the widow in order to unlock the door using the manual door lock knob.
  4. Open the door.

The system enters the alarm state. The following actions occur for approximately 2 minutes:

    • The horns sound intermittently.
    • The exterior lamps flash ON and OFF.
    • After 2 minutes, the system automatically returns to the armed state.

Return System to Arm Initiated State

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

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

    4. The system does not enter the alarm mode. The system indicator flashes ON and OFF. The flashing indicator indicates that the system has entered the ready-to-arm state.

  4. Press the power door lock switch to the LOCK position or the key fob LOCK button.

Ignition Switch Disarm Function

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

  1. Remain inside the vehicle.
  2. Place the system in the armed state.
  3. Wait for the SECURITY indicator to turn OFF. The system is armed when the SECURITY indicator turns OFF.
  4. Cycle the ignition switch from the LOCK (OFF) position to the RUN position. Return the ignition switch to the LOCK (OFF) position.
  5. Open any door.

The system does not enter the alarm mode. The SECURITY indicator flashes. The flashing indicator indicates that the system has entered the ready-to-arm state.