B2958

CIRCUIT DESCRIPTION
The Passlock(TM) system is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate or the ignition switch is operated while separated from the ignition lock cylinder case. The body control module (BCM) provides security system sensor power and low reference for the Passlock(TM) sensor. The BCM also measures the security system sensor voltage.

When the correct key is used to start the vehicle, a magnet on the lock cylinder passes close to the Passlock(TM) sensor within the ignition lock cylinder case. The magnet activates the security hall effect sensor in the Passlock(TM) sensor which completes a circuit from the security sensor signal circuit through a resistor to the security sensor low reference circuit. The resistance value will vary from vehicle to vehicle. The BCM will measure the voltage on the security sensor signal circuit and compare this voltage to a previously learned voltage. If the voltage measured is within the valid range, the BCM will send a class 2 message to the powertrain control module (PCM) to enable vehicle starting. If the voltage measured is not within the valid range, a class 2 message will be sent to the PCM to disable starting of the vehicle.

CONDITIONS FOR SETTING THE DTC
- The ignition switch is ON.
- The BCM signal input is greater than 4.9 volts for 1 second after turning the ignition switch to the CRANK position.

ACTION TAKEN WHEN THE DTC SETS
- The DTC will set only when the engine is running
- The BCM will be in the fail enable mode allowing the vehicle to start and run.
- The security indicator will be ON.

CONDITIONS FOR CLEARING THE DTC
- The current DTC will clear once an ignition cycle has occurred without the fault recurring.
- After 100 concurrent ignition cycles occur without the fault recurring, a history DTC clears.
- Using a scan tool.

DIAGNOSTIC AIDS
- Use a scan tool in order to inspect the Passlock(TM) data voltage and the Passlock(TM) code.
- Inspect the Passlock(TM) sensor harness for an intermittent or a short to battery. Refer to Diagnostic Aids for Circuit Testing and Wiring Repair procedures.
- You may be directed to this table from the VTD Diagnostic System Check without a DTC B2958 being set. If you were directed to this table, follow all of the steps in this diagnostic table.
- When directed to this table, DTC B2958 may have a history status.

TEST DESCRIPTION

Steps 1-3:

Steps 4-8:

Steps 9-14:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for proper operation of the circuit in the high voltage range.
4. Tests for proper operation of the circuit in the low voltage range.
5. Tests for high resistance or an open in the 12V reference circuit.
7. Tests for a short to voltage, a high resistance, or an open in the signal circuit.
8. Tests for high resistance or an open in the ground circuit.