Personal Automotive Security System (PASS-Key II) Operation
PERSONAL AUTOMOTIVE SECURITY SYSTEM (PASS-Key II) OPERATION
PASS-Key II is a registered trademark of Delco Electronics Corporation.
When a key is inserted in the ignition, contacts located in the ignition cylinder contact a resistor pellet located in the key. The Instrument Panel Cluster (IPC) measures the resistance of the key pellet and then compares this value to a value stored in the IPC's memory. The IPC, then performs one of the following functions:
* If the values match, the IPC performs the following (system enable) functions:
^ Provides a ground for the Starter Enable Relay, enabling the starter to operate.
^ Sends a Class 2 message to the Powertrain Control Module (PCM), the PCM then enables the fuel system to operate.
* If the values do not match, the IPC performs the following (system disable) functions for approximately three minutes:
^ No ground provided to the Starter Enable Relay, disabling the starter.
^ No system enable Class 2 message is sent to the PCM, the PCM does not enable the fuel system for approximately three minutes
If the ignition switch is turned to the RUN position anytime during the system disable interval, the IPC disregards the key pellet value until the three minute system disable interval is complete (even if the correct key pellet value was used).
After approximately three minutes, the IPC measures the key pellet resistance and compares it to the one stored in the IPC's memory. If the values match, the IPC performs the system enable function (see above). If the values do not match, the IPC performs the system disable functions again (see above).
If the IPC is unable to measure the key pellet resistance (due to a damaged or missing pellet), the IPC does not perform system disable functions (a readable key with the correct resistance value can be used to start the vehicle).
WARNING MESSAGES
For additional message information and diagnostics, refer to Instrument Panel Cluster Diagnosis. Testing and Inspection
STARTING DISABLED DUE TO THEFT SYSTEM REMOVE IGNITION KEY
If the PCM does not receive the fuel enable message, the PCM sends a message to the IPC to display the STARTING DISABLED DUE TO THEFT SYSTEM REMOVE IGNITION KEY message on the Driver Information Center, via the Class 2 serial data line. This informs the driver why the engine is not starting and starts a three minute interval, with messages, before attempting a vehicle restart.
WAIT 3 MINUTES, WAIT 2 MINUTES, WAIT 1 MINUTE, and START CAR
When the ignition switch is returned to the OFF position, the IPC starts a timer and at one minute intervals displays the following messages: WAIT 3 MINUTES, WAIT 2 MINUTES, WAIT 1 MINUTE, and START CAR. These messages inform the driver to wait for the PASS-Key II system to reset, before attempting to restart the vehicle.
REMOVE KEY
Following the WAIT 3 MINUTES, WAIT 2 MINUTES, WAIT 1 MINUTE, and START CAR messages, alternating every three seconds, the IPC displays the REMOVE KEY message. This informs the driver that the key should be removed, before attempting to restart the vehicle.
THEFT SYSTEM PROBLEM CAR MAY NOT RESTART
The THEFT SYSTEM PROBLEM CAR MAY NOT RESTART message is displayed, when the engine is running and the IPC has detected a PASS-Key II system malfunction. The vehicle continues to run, but if the error is present when the vehicle is turned off, the vehicle may not restart.
SECURITY INDICATOR OPERATION
When the ignition switch is turned to the ON position, the security indicator illuminates for approximately five seconds, indicating to the driver that the system is operating correctly.
The four bulb control modes for the PASS-Key�II system are listed below.
Bulb Stays Illuminated and Engine Starts
If the security indicator stays illuminated after the engine starts, this is an indication that one of the following conditions has occurred:
The IPC is not properly programmed, more than one key code value can be used to start the vehicle. The improperly programmed IPC condition usually occurs on a vehicle where the IPC has been recently replaced. Refer to Programming the Instrument Panel Cluster in Instrument Panel Cluster Diagnosis. Programming and Relearning
^ The IPC detected a malfunction in the PASS-Key II system while the engine was last running. Verify that the IPC connections are secure and that a good ignition key is being used. For further diagnosis, refer to Instrument Panel Cluster Diagnostic System Check in Instrument Panel Cluster Diagnosis. Initial Inspection and Diagnostic Overview
Bulb Stays Illuminated and Engine Does Not Start
If the security indicator stays illuminated while attempting to start the engine and the engine does not start, the IPC has detected an incorrect key pellet resistance (key code) value and activated the system disable functions. The following actions should be taken:
1. Remove the key from the ignition
2. Verify that the correct key code (key pellet) is being used to start the vehicle. Using J 35628-A, measure each key pellet for the vehicle, all the key codes should match.
3. Wait approximately 3 minutes for the system disable timer to expire, attempt to restart the engine using a known good key with the correct key code.
4. If the engine still won't start, refer to Theft Deterrent System Check. Testing and Inspection
Bulb Flashes and Engine Does Not Start
If the security indicator flashes and the engine does not start, the IPC has detected an open or short in the ignition key resistor input circuit. During this mode of operation the IPC will not start the system disable timer. Refer to Theft Deterrent System Check. Testing and Inspection
SYSTEM COMPONENTS
IGNITION KEY
The ignition key for vehicles equipped with the PASS-Key II system, consist of a typical square ignition key blank and a resistor pellet. The PASS-Key II ignition key has the same mechanical key cuts of a non PASS-Key II ignition key. The key blank and resistor pellet can not serviced separately. There are 15 different ignition key assemblies, each with a different key pellet resistance value.
STEERING COLUMN LOCK CYLINDER
The steering column lock cylinder used with the PASS-Key II system contains a set of electrical terminals used to contact the resistor in the ignition key. The wire routing for the contacts inside the steering column is very critical. When servicing the lock cylinder, be certain to maintain proper wire routing. When replacing a steering column lock cylinder, it will be necessary to make new keys which match the PASS-Key II key code of the PASS-Key II system and the mechanical cut of the new lock cylinder.
INSTRUMENT PANEL CLUSTER (IPC)
The IPC contains the software for controlling the PASS-Key II system. The IPC monitor the key-in-ignition input (CKT 80, LT GRN) and the ignition key resistor input (CKT 1O73, WHT/BLK). The IPC controls the starter enable output (CKT 625,YEL/BLK). The IPC also sends a fuel enable message to the PCM, via the class 2 serial data line.
Key-In-Ignition Input
The key-in-ignition input (CKT 80, LT GRN) is used to wake up the IPC, when a key is inserted into the steering column lock cylinder (ignition switch). When the IPC wakes up, the IPC measures the key pellet resistance value on the ignition key resistor input (CKT 1O73, WHT/BLK ).
Ignition Key Resistor Input
The ignition key resistor input (CKT 1O73, WHT/BLK) is used by the IPC to measure the key pellet resistance.
Starter Enable Output
The starter enable output (CKT 625, YEL/BLK) is used by the IPC to control the starter enable relay.
STARTER ENABLE RELAY
The starter enable relay is controlled by the IPC, via the starter enable output (CKT 625, YEL/BLK). If the IPC measures the correct key pellet resistance value, the IPC switches the starter enable output (CKT 625, YEL/BLK) to ground. The relay is energized if the ignition switch is in the START position and the gear selector is in the PARK or NEUTRAL positions.
POWERTRAIN CONTROL MODULE (PCM)
The PCM monitors the Class 2 serial data line for the fuel enable message from the IPC. If the fuel enable message is not present, the PCM does not enable the fuel system during engine crank. If the message is present, the PCM enables the fuel system, which allows the engine to start during engine crank.