Pass-Key (R) II Theft Deterrent

The Personal Automotive Security System (PASS-key (R) II) is a vehicle theft deterrent system. The PASS-key� II is designed in order to prevent vehicle theft by disabling the engine from starting unless an ignition key with a specific resistor pellet code is used in the ignition lock cylinder.

The ignition lock cylinder contains the resistor sensing contacts. These contacts touch the resistor pellet embedded in the ignition key. When the ignition key is inserted in the ignition lock cylinder, the resistor pellet completes the key detection circuit (CKT 1073 and CKT 1074).

When the ignition switch is turned from the OFF to the RUN position, the BCM applies a 5 V reference voltage to CKT 1073. The BCM reads the resistor pellet code and compares the stored resistor pellet code against the ignition key resistor pellet code for a correct match.

Upon detecting a correct match, the BCM sends a fuel enable password to the PCM through the Class 2 serial data link. As a result, the PCM enables the theft deterrent relay. This action allows fuel delivery to the engine.

If the key resistor pellet is incorrect, the PCM performs the following actions:
^ Disables the theft deterrent relay
^ Stops fuel delivery to the engine

This vehicle disable period state lasts approximately 3 minutes. The SECURITY indicator flashes when the ignition switch is turned to the RUN position. Disconnecting the battery will not clear the timer sequence. The timer sequence resumes when the battery power is restored. If a proper key is inserted during the vehicle disable period, the vehicle will not start until the 3 minute time period elapses. After the 3 minute time period, the SECURITY indicator changes from a flashing state to a solid ON state. At this time, the BCM enters the theft deterrent re-learn mode. The engine will start if the correct ignition key resistor pellet is used.

Refer to Content Theft Deterrent (CTD) Circuit Description in Theft Deterrent for more information.