Circuit Description
The Personal Automotive Security System (PASS-Key® II) is a vehicle theft deterrent system. The PASS-Key® II is designed in order to prevent vehicle theft by disabling the engine from starting unless an ignition key with a specific resistor pellet code is used in the ignition lock cylinder.
The ignition lock cylinder contains the resistor-sensing contacts. These contacts touch the resistor pellet that is embedded in the ignition key. When the ignition key is inserted in the ignition lock cylinder, the resistor pellet completes the key detection circuit (CKT 1073 and CKT 1074).
When the ignition switch is turned from the LOCK or the OFF position to the RUN position, the BCM applies a 5 V reference voltage to CKT 1073. The BCM reads the resistor pellet code and compares the stored resistor pellet code against the ignition key resistor pellet code for a correct match.
When the BCM detects a correct match, the BCM sends a fuel-enable password to the Powertrain Control Module (PCM) through the Class 2 serial data link. The PCM enables the theft deterrent relay. This action allows fuel delivery to the engine.
Conditions for Setting the DTC
| • | The voltage detected in CKT 1073 by the BCM is low. This condition indicates that a short to ground is present. |
| • | The condition is present during an engine start attempt. |
| • | The condition is present for 1 second anytime after the engine has started. |
Action Taken When the DTC Sets
| • | The BCM stores DTC B2957 in the memory. |
| • | The BCM sends a message to the IPC in order to turn on the SECURITY indicator through the Class 2 serial data link. |
| • | The BCM performs one of the two following actions: |
| - | If CKT 1073 is shorted to ground when attempting to start the engine, the BCM will NOT send a message to the PCM to enable the theft deterrent relay or to deliver fuel to the engine. The engine will exhibit an engine no-crank condition. |
| - | If CKT 1073 is shorted to ground after the engine has started, the BCM enters a fail-enable mode. Upon subsequent engine start attempts, the BCM sends a password message to the PCM via the Class 2 serial data link in order to enable theft deterrent relay and deliver fuel to the engine. The engine will start. |
Conditions for Clearing the MIL/DTC
| • | The BCM detects a valid PASS-Key® II resistance value on the PASS-Key® II input circuit (CKT 1073). |
| • | A history DTC clears after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
| • | Use a Scan Tool in order to clear the DTC. |
Diagnostic Aids
| • | Inspect for a short between CKT 1073 and CKT 1074. |
| • | Inspect for a short to ground in CKT 1073. |
| • | The following conditions may cause an intermittent malfunction to appear: |
| - | A shorted key resistor pellet |
| - | Shorted ignition key cylinder contacts |
| - | An intermittent short to ground in CKT 1073 |
| - | An intermittent short between CKT 1073 and CKT 1074 |
| - | The BCM interprets this condition as a short to ground. |
| • | If the DTC is a history DTC, the condition may be intermittent. Perform the tests shown while moving the wires and connectors. This action may often cause the malfunction to reappear. |
| • | The DTC P1626 sets in the Powertrain Control Module (PCM) when the ignition switch is in the RUN position and the BCM is disconnected. When BCM diagnostics and repairs are completed, refer to Engine Controls for additional information on PCM-related DTCs. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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This step inspects if the PASS-Key® II resistor pellet is within the allowable range.
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This step tests for a short to ground on the ignition lock cylinder and the pigtail circuit.
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This step tests for a short to a ground in CKT 1073.
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This step tests for a short between CKT 1073 and CKT 1074. The BCM interprets this condition as a short to ground.
-
This step determines if the malfunction is intermittent or if the BCM is faulty.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the BCM Diagnostic System Check performed? | -- | Go to Step 2 | |
Inspect the vehicle's key code number by inserting the ignition key into the J 35628-A . Does the J 35628-A indicate a valid key code in the specified range? | 1-15 | Go to Step 3 | Go to Step 11 | |
Does the resistance equal the specified value? | Infinite | Go to Step 4 | Go to Step 7 | |
Does the resistance equal the specified value? | Infinite | Go to Step 5 | Go to Step 9 | |
Using the J 39200 DMM, measure the resistance between the BCM harness connector C1 terminal D2 and terminal D3. Does the resistance equal the specified value? | Infinite | Go to Step 7 | Go to Step 10 | |
Does DTC B2957 reset as a current DTC? | -- | Go to Step 8 | Go to Step 12 | |
7 | Replace the ignition lock cylinder. Refer to Steering Column Lock Cylinder Set - Disassemble - Off Vehicle in Steering. Is the repair complete? | -- | Go to Step 6 | -- |
8 |
Is the repair complete? | -- | Go to Step 13 | -- |
9 | Repair the short to ground in CKT 1073. Is the repair complete? | -- | Go to Step 13 | -- |
10 | Repair the short between CKT 1073 and CKT 1074. Is the repair complete? | -- | Go to Step 13 | -- |
11 | Replace the ignition key. Refer to Programming Replacement Keys, Ignition Cylinder, or Powertrain Control Module in Theft Deterrent. Did you replace the key? | -- | Go to Step 13 | -- |
12 | A malfunction is not present at this time. Refer to Diagnostic Aids for additional information. Is the action complete? | -- | Go to Step 13 | -- |
13 |
Are any current BCM DTCs set? | -- | System OK |
