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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Impala 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 Content Theft Deterrent (CTD) Description

Theft Deterrent System

The theft deterrent system on this vehicle is comprised of the Vehicle Theft Deterrent (VTD) system and the optional Content Theft Deterrent (CTD) system. VTD may be thought of as the vehicle's immobilizer system, preventing drive away theft by keeping the vehicle from starting. CTD is the vehicle alarm system which discourages unauthorized entry into the vehicle. These system are described and diagnosed separately within this section. For VTD description and operation, refer to Vehicle Theft Deterrent (VTD) Description and Vehicle Theft Deterrent (VTD) Operation .

SECURITY Indicator

The yellow indicator SECURITY in the instrument cluster message center is controlled by both the VTD system and the CTD system.

    • The VTD system commands the instrument cluster to control the indicator only when the ignition switch is ON. The VTD System uses the indicator as a malfunction indicator. If a DTC is present in the VTD system when the Ignition is ON, the indicator will be illuminated.
    • The CTD system commands the instrument cluster to control the indicator only when the ignition switch is OFF. The CTD System uses the indicator in order to identify system status.
       - Indicator FLASHING -- The system is in standby mode, the system is not ready to arm (a door is open).
       - Indicator ON STEADY -- The system is in delay mode, the system is ready to arm and is executing a time delay of 30 seconds before turning the lamp OFF and transitioning to the armed mode
       - Indicator OFF -- The system may or may not be armed.

Another indicator, on the face of the radio, is activated when the ignition is OFF and the theft deterrent system is ready for arming or is armed. This indicator serves a dual purpose as both a radio indicator and the theft deterrent armed indicator.

    • Indicator On -- Ignition Off, Door Locks On, Door Open ready for individuals to exit
    • Indicator Flashing -- System Armed, Door Closed and Locked

The content theft deterrent (CTD) system consists of the following components:

    • The body control module (BCM) 
    • The door lock cylinders
    • The rear compartment lock cylinder
    • The security indicator lamp
    • Security armed indicator lamp in radio
    • The door lock switches
    • The key cylinder lock switches
    • The keyless entry system
    • The power door lock switches
    • The rear compartment courtesy lamp switch
    • The rear compartment lock cylinder switch

Body Control Module (BCM)

The body control module (BCM) controls the CTD. The BCM monitors the status of the following components:

    • The vehicle doors
    • The lock cylinders
    • The keyless entry system

The BCM operates the following components, according to the chosen mode of operation:

    • The park lamps
    • The horn
    • The status security indicator lamps

The BCM also communicates a fuel enable signal to the powertrain control module (PCM).

Key Cylinder Lock Switch

The door key cylinder locks have integral switches that signal the BCM to disarm the system theft deterrent system.

Rear Compartment Lock Cylinder

The rear compartment lock cylinder has an integral switch that sends a signal to the BCM when the rear compartment lock cylinder is removed from the rear compartment lid.

Security Indicator Lamp

The BCM controls the operation of the security indicator lamp. The security indicator lamp may be in one of the following modes:

  1. On
  2. Off
  3. Flashing slow
  4. Flashing fast

The security indicator lamp mode depends on the content theft deterrent (CTD) system mode.