System Operation

SYSTEM OPERATION

The Personal Automotive Security System (PASS-Key II) is designed to prevent the engine from starting if the proper resistance is not sensed from the ignition key assembly. Of the 15 key codes (resistance values) available, only one will work with each theft deterrent module assembly.

The PASS-Key II system prevents the engine from starting by controlling the theft deterrent relay assembly and the Engine Control Module (ECM) fuel enable input. If the ECM does not sense the proper pulse width modulate (PWM) signal on the fuel enable input, it will not provide fuel to the engine.

If the wrong resistance value is sensed when the ignition switch is in the "RUN" position, the theft deterrent module assembly will not ground the starter enable circuit and will not output the fuel enable PWM signal for approximately three minutes. This prevents the engine from starting and discourages the thief from trying key codes (resistance values) at random.

If the correct resistance value is sensed when the ignition switch is in the "RUN" position, the theft deterrent module assembly will ground the starter enable circuit and output the fuel enable PWM signal. This will allow the engine to start normally.