GM Service Manual Online
For 1990-2009 cars only

The content theft deterrent system is designed to deter vehicle vandalism and theft. The content theft deterrent system is optional equipment (RPO UA6).

The content theft deterrent system performs these functions:

  1. Flashes the headlamps
  2. Sounds the horn
  3. Disables fuel delivery to the engine

The content theft deterrent system is not susceptible to disarming by removing power or ground feeds to the Body Control Module (BCM). Refer to Content Theft Deterrent (CTD) Description

System Components

The main component of the content theft deterrent system are:

    • Body Control Module (BCM) type 4.
    • Door lock switches.
    • Key cylinder lock switches.
    • Keyless entry system.
    • Power door lock switches.
    • Powertrain Control Module (PCM).
    • Rear compartment courtesy lamp switch.
    • Rear compartment lock cylinder switch.
    • Security indicator lamp.
    • Shock sensor.
    • Theft deterrent relay.

Body Control Module (BCM)

The Body Control Module (BCM) type 4 controls the content theft deterrent system. The BCM monitors the status of the doors, lock cylinders, rear compartment lid, shock sensor, power door locks, and the keyless entry system.

The BCM operates the headlamps, horn, and the security indicator lamp according to the mode of operation the system is in. The BCM also communicates a fuel enable signal to the Powertrain Control Module (PCM) when the system is disarmed.

Checking for Correct BCM Type

Perform the procedure when checking the BCM type installed in the vehicle.

  1. Turn the ignition switch to the OFF position.
  2. Remove the Mall PGM fuse.
  3. Turn the ignition switch to the ACC position.

The seat belt indicator flashes and the chime sounds, 2, 3 or times  indicating the BCM type that is installed in the vehicle.

Verify that a BCM type 4 is installed on a vehicle with RPO UA6. Refer to the Service Parts Identification Label and the RPO Code list in the General Information for details.

If the vehicles has RPO but does not have a BCM type 4, then replace and install a BCM type 4, then refer to Body Control Module Diagnostic Information in Body Control System for more information.

Key Cylinder Lock Switch

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

Powertrain Control Module (PCM)

The Body Control Module (BCM) interfaces with the Powertrain Control Module (PCM) to either enable or disable fuel delivery to the engine When the content theft deterrent system is armed, the Powertrain Control Module (PCM) disables the fuel injectors. This action causes a crank no start condition when attempting to start the engine with the system armed.

When the content theft deterrent system is disarmed, the BCM sends a fuel enable signal to the Powertrain Control Module (PCM) through the fuel enable circuit. The PCM then enables fuel delivery to the engine, allowing the engine start.

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 BCM may be on, off, flashing slow or fast the security indicator lamp based on the current system operating mode.

Shock Sensor

The shock sensor sends a tamper signal to the BCM if an impact to the vehicle occurs considered to be a vehicle tamper condition, or glass breakage.

Theft Deterrent Relay

The BCM controls the theft deterrent relay, causing to turn on the headlamps during certain modes of operation.