General Information

The personal automotive security system (PASS-Key(R)) system is designed to prevent the engine from starting if the proper resistance is not sensed from the ignition key. Of the 15 different key codes or resistance values available, only one will work with each Body Control Module (BCM). Once the key code is programmed into the BCM, the resistance value is stored in a non-volatile memory.

The PASS-Key(R) system prevents the engine from starting by controlling the starter relay and the powertrain control module (PCM) fuel enable input. If the PCM does not sense the proper frequency signal on the fuel enable input, fuel will not be provided to the engine.

If the wrong resistance value is sensed when the ignition switch is in the RUN position, the BCM will not ground the starter enable circuit and will not output the fuel enable signal for approximately three minutes. The engine is prevented from starting and discourages a thief from trying key codes or resistance values at random.

If the correct resistance value is sensed when the ignition switch is in the RUN position, the BCM will ground the starter enable circuit and output the fuel enable signal. The engine will start normally. If the PASS-Key(R) system detects an open or short to ground when the ignition switch is in the RUN position, the BCM will default to fail enable. Fail enable occurs when the proper key resistance is sensed before the open short to ground occurs. This has to occur for 1 minute before the fail enable is engaged. Fail enable will illuminate the security indicator lamp and allow the operator to stop and start the vehicle until the problem is corrected.