Pass-Key(R) II System: Notes

WARNING: This page is about a different car, the 2001 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.

Personal Automotive Security System (PASS-Key(R)) is standard equipment on vehicle. System is designed to prevent vehicle theft by disabling engine unless an ignition key with a specific electrical resistance is used in ignition cylinder. There are 15 different ignition key resistance values. Of 15 different resistance values, or key codes available, only one will work with Instrument Panel Cluster (IPC). Once key code is programmed into IPC, code is stored in non-volatile memory.

PASS-Key(R) system prevents engine from starting by controlling theft deterrent relay and Powertrain Control Module (PCM) fuel enable input. If PCM does not sense proper fuel enable signal, fuel will not be provided to engine. If wrong resistance value is sensed when ignition switch is in RUN position, PCM will not ground theft deterrent relay control circuit and will not enable fuel system for approximately 3 minutes. Engine is prevented from starting and discourages a thief from trying key codes or resistance values at random.

If correct resistance value is sensed when ignition switch is in RUN position, PCM will ground theft deterrent relay control circuit and enable fuel delivery. Engine will start normally.

If PASS-Key(R) system detects an open or short to ground when ignition switch is in RUN position, IPC will default to fail enable mode. Fail enable occurs when proper key resistance is sensed before short to ground occurs. Fail enable will illuminate SECURITY indicator massage and allow operator to stop and start vehicle until problem is corrected. PASS-Key(R) system includes the following components:

Ignition Key.
Ignition Cylinder.
Instrument Panel Cluster (IPC).
Theft Deterrent Relay.
Powertrain Control Module (PCM).
SECURITY Indicator.