Passlock™ Theft Deterrent
The Passlock™ is a vehicle theft deterrent system. The Passlock™
theft deterrent system contains a Passlock™ sensor. The Passlock™
sensor is part of the ignition lock cylinder assembly. The body control
module (BCM) provides power and ground to the Passlock™ sensor. The
Passlock™ sensor interfaces with the BCM through the Passlock™
detection circuit 1836.
When turning the ignition switch to the start position with the proper
key, the Passlock™ sensor generates an analog voltage signal. This signal
is sent through the Passlock™ detecting circuit. This analog voltage
signal is of a specific value to the vehicle, and varies from vehicle to
vehicle. When attempting to start the engine, the BCM compares a preset
stored analog voltage value with the signal coming from the sensor. Because
both values match, the BCM sends a fuel enable password via the Class 2
serial data link to the powertrain control module (PCM). As a result, the
PCM enables the crank relay, and allows fuel delivery to the engine.
When attempting to start the engine by means other than using the proper
key in the ignition switch, the Passlock™ sensor sends a analog voltage
signal of a different value. The BCM compares the preset stored analog
voltage value with the signal coming from the Passlock™ sensor. Because
both values do not match, the BCM sends a fuel disable password via the
Class 2 serial data link to the powertrain control module (PCM).
As a result, the PCM disables the crank relay, and does not allow fuel delivery
to the engine.
Refer to
Body Control System Operation
in Body Control Module for more information regarding the
BCM.
BCM Inputs
The following components provide direct input to the BCM, plus other
systems can use this input information in order to carry out Passlock™
theft deterrent functions:
• | BCM Ground: Provides ground for BCM operation. |
• | BCM Power: Provides voltage for BCM operation. |
• | Crank Signal: Determines when the ignition switch is in the start
position. |
• | Ignition 0 Signal: Determines when the ignition switch is in accessory,
on, and start positions. |
• | Ignition 1 Signal: Determines when the ignition switch is in the
on, bulb test, and start positions. |
• | Passlock™ Sensor Data: Reads the Passlock™ sensor
security code. |
• | Serial Data: Provides an interface with the PCM through the Class 2
serial data link. |
BCM Outputs
The BCM directly controls these outputs for Passlock™ theft deterrent
functions:
• | Passlock™ Sensor Power: Provides B+ for Passlock™ sensor
operation. |
• | Passlock™ Sensor Ground: Provides ground to the Passlock™
sensor. |
• | Serial Data: Provides an interface with the PCM and the instrument
cluster through the Class 2 serial data link. |
Theft Deterrent Re-Learn
Perform the Theft Deterrent Re-Learn procedure when:
• | The BCM has been replaced in the vehicle and the Setup New BCM
procedure has been successfully completed. |
• | The ignition key cylinder assembly has been replaced. |
Refer to
Body Control Module (BCM) Programming/RPO Configuration
in Body Control System for the Theft Deterrent Re-Learn
and the Setup New BCM service procedures.