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Vehicle Theft Deterrent (VTD)

The red security indicator is a distributed function between the BCM and the instrument cluster. The BCM determines the status of the security indicator based on its internal Passlock(R) algorithm and what has been communicated to it from the PCM Passlock(R) algorithm. The BCM then forwards a status of either OFF, ON or FLASH to the instrument cluster over the Class 2 serial data bus. If the indicator status is FLASH, the instrument cluster actually controls the flash rate/timing.

The SECURITY indicator shows whether the Passlock(R) data has passed. The BCM sends a message to turn the SECURITY indicator on or off to the instrument panel cluster (IPC) via the Class 2 serial data bus.

The SECURITY indicator is on when the BCM is not in the auto-learn mode and either of the following conditions is true:
^ Any theft deterrent DTC is set
^ The PCM Vehicle Theft Deterrent Fail-Enable bit is true in the last vehicle security status message received.

The SECURITY indicator flashes when either of the following conditions is true:
^ The BCM detects a tamper
^ The PCM Fuel Disable Time-out bit is set in the last vehicle security status message received since the ignition switch was turned to the ON position

If the BCM is in a 10-minute tamper and the ignition switch is turned to the OFF position, the instrument cluster remains awake and flashes the SECURITY indicator until the BCM requests a status of OFF. The instrument cluster has a maximum wait time defined.