B2948

Circuit Description
The Body control module (BCM) supplies power to the Passlock sensor on CKT 812.

When the Passlock sensor is powered and the ignition switch is rotated to the CRANK position, the hall effect security sensor will latch and provide a code to the BCM. The BCM will then compare this code to the code in the previous ignition cycle. If the latched value is the same as the last ignition cycle value, the test has passed. When the ignition switch is switched to the OFF position, the sensor is no longer powered and resets the sensor latch circuit.

In the next ignition cycle, the Passlock sensor waits for an ignition switch crank input and verifies the sensor code and compares the sensor code to the last stored valid code.

Conditions for Setting the DTC
- The ignition switch is in the OFF position.
- The BCM turns the sensor power OFF for approximately 0.1 seconds when the ignition switch is turned OFF.
- During the 0.1 second shut down of voltage, if the BCM senses battery voltage the DTC will set.
- The sensor power will turn OFF after the 20 minute BCM shut down period.

Action Taken When the DTC Sets
The vehicle will continue to start and run with the security indicator ON.

Conditions for Clearing the DTC
- The DTC clears once an ignition cycle occurs without the fault recurring.
- The BCM history codes will clear after 100 concurrent ignition cycles occur without the fault recurring.
- Use a scan tool in order to clear history and current DTCs.

Diagnostic Aids
- When replacing the Passlock sensor, all of the following components are included as a replacement part and must be replaced:
- The lock
- The sensor
- The filter
- The harness
- Use a scan tool in order to inspect the Passlock data voltage and the Passlock code.
- Perform a visual inspection of the wiring and the connectors.
- Inspect the Passlock sensor harness for an intermittent or a short to battery. Refer to Intermittents and Poor Connections in Overall Vehicle Information/Testing and Inspection.

Steps 1 - 4:

Step 5:

Steps 6 - 7:

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step isolates the short to battery between the BCM and the harness.
3. This step isolates the short to battery between the Passlock sensor and the harness.