The personal automotive security system (PASS-Key®) is standard equipment on the vehicle. The system is designed to prevent vehicle theft by disabling the engine unless an ignition key with a specific electrical resistance is used in the ignition cylinder.

There are 15 different ignition key resistance values. Of the 15 different resistance values, or key codes available, only 1 will work with each body control module (BCM). Once the key code is programmed into the BCM, the code is stored in non-volatile memory.

The PASS-Key® 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 fuel enable signal, fuel will not be provided to the engine.

If the wrong resistance value is sensed when the ignition switch is in the ON position, the BCM will not ground the starter relay control circuit and will not provide the fuel enable signal for approximately 3 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 ON position, the BCM will ground the starter relay control circuit and will send a fuel enable signal to the PCM. The engine will start normally.

If the PASS-Key® system detects an open or short to ground when the ignition switch is in the ON position, the BCM will default to fail enable mode. Fail enable occurs when the proper key resistance is sensed before the open or short to ground occurs. Fail enable will illuminate the security indicator lamp and allow the operator to start the vehicle until the problem is corrected. There is no VTD protection in fail enable mode. The PASS-Key® system includes the following components:

The ignition key is a typical square ignition key blank with an imbedded resistor. The key blank and resistor are not serviceable separately. There are 15 different resistance values. The ignition key also has mechanical cuts similar to non-PASS-Key® ignition keys.

The ignition cylinder contains a set of electrical contacts used to measure the resistor in the ignition key. When the ignition key is inserted into the lock cylinder, the resistor in the key makes contact with the electrical contacts inside the ignition cylinder.

The body control module (BCM) contains the theft deterrent system logic. The BCM reads the key code from the ignition cylinder when the ignition is turned to the START position. If the code is correct, the BCM will enable the starter relay and will send a fuel enable signal to the PCM.

If the BCM receives the wrong code, the BCM will immediately go into tamper mode. The tamper mode will lock-out the vehicle starter and fuel injectors for 3 minutes. The SECURITY indicator will flash while the BCM is in tamper mode.

The starter relay is used to prevent the engine from cranking if the correct resistance is not sensed at the ignition key. It prevents the engine from cranking by opening the ground circuit to the starter solenoid.

The PCM communicates with the BCM through the class 2 serial data circuit. When the BCM enters tamper mode, it sends a message to the PCM in order to disable the fuel injection system. If the BCM receives the expected ignition code, the BCM sends a message to the PCM in order to enable the fuel injection system. The PCM then allows the vehicle to start.

The SECURITY indicator is located on the instrument cluster. The SECURITY indicator is controlled by the BCM. The SECURITY indicator will illuminate on IPC system prove out, when an incorrect key is used to attempt to start the vehicle, or when fail enable mode is active.