Theft Deterrent System Class 2 Communications

In order to operate, the Passlock(TM) system requires communication of various functions between the VCM and the Passlock(TM) module. These functions transmit over the Class 2 serial data line, or CKT 1807 (PPL). For an explanation of the Class 2 serial data operation, refer to Computer System Diagnosis. Testing and Inspection

Scan Tool Diagnosis
Refer to the Scan Tool Owner's manual for information about the scan tool and the various modes.

Data List
The scan tool may list the Passlock(TM)/EVO module data list. This list shows the status of the hardwire connections to the Passlock(TM) module. The data list is very useful in diagnosing the Passlock(TM) system.

Auto Learn Timer Status
The auto learn timer is part of the interactive procedure which allows learning of the Passlock(TM) data in service in a period of approximately 30 minutes.

Lockout Timer Status
The Lockout Timer is the period of 10 minutes the Passlock(TM) module waits through in the event of a Tamper Mode, even if the ignition switch is in the OFF position.

Password
The password is a coded message sent by the Passlock(TM) module to the VCM when the engine starts. The VCM then compares the data receive with the stored data. If the data matches, the VCM keeps the vehicle operating. Otherwise, the VCM immediately stops the engine.

Passlock(TM) Data Voltage
The Passlock(TM) signal is an analog input voltage generated by a voltage divider network. The Passlock(TM) module determines whether this voltage value is valid.

Passlock(TM) Power
The Passlock(TM) module supplies the Passlock(TM) power signal to the Passlock(TM) sensor.

SECURITY Indicator State
The SECURITY indicator state indicates whether the Passlock(TM) module passes the Passlock(TM) data. the Passlock(TM) module supplies a ground to the security lamp driver circuit illuminating the SECURITY indicator at the instrument cluster. The SECURITY indicator illuminates when any DTC sets, or if the SECURITY indicator lamp driver circuit shorts to ground. The Passlock(TM) module flashes when a tamper condition exists, or when the fuel enable lockout bit sets during the last status message received from the VCM.