Vehicle Theft Deterrent (VTD)Circuit Description. Buick GL7 (Export) 2000

For 1990-2009 cars

### (VTD) Theft Deterrent System Components

#### Ignition Key (Transponder)

The ignition key for the (VTD) theft deterrent system is a typical ignition key with a transponder pellet located in the plastic end of the key. The ignition key transponder value is used to determine if a valid ignition key is being used to start the vehicle, there are approximately three trillion different transponder values available. This vehicle has one type of ignition key.

Master key (black plastic end) which can start the vehicle and lock/unlock all door locks and all storage compartments.

Important: The transponder values are not readable and can not be serviced separately.

#### Theft Deterrent Module

The theft deterrent module contains the software for controlling the VTD System. The theft deterrent module uses the following inputs and outputs to control the VTD system.

#### Inputs

• | Battery voltage from the fuse block.

• | Ignition voltage from the ignition switch.

• | Ground circuit.

#### Outputs

Password exchange with the PCM (fuel enable), class 2 serial data circuit .

#### Powertrain Control Module (PCM)

The PCM verifies that the passwords received from the theft deterrent module via the class 2 serial data line are valid. If a password is invalid the PCM disables the fuel delivery system. If the password is valid the PCM enables the fuel delivery system.