Circuit Description
The Passlock 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 Passlock module provides security system sensor power and low reference for the Passlock sensor. the Passlock module 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 sensor within the ignition lock cylinder case. The magnet activates the security hall effect sensor in the Passlock 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 Passlock module 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 Passlock module 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 in the OFF position. |
| • | The Passlock module turns the sensor power OFF when the ignition switch is turned OFF. |
| • | During the 0.1 second shut down of voltage, if the Passlock module senses battery voltage the DTC will set. |
Action Taken When the DTC Sets
| • | The vehicle will continue to start and run with the security indicator ON. |
| • | The Passlock module stores DTC B2948 in memory. |
The vehicle will continue to start and run with the security indicator ON.
Conditions for Clearing the DTC
| • | The DTC changes from current to history once an ignition cycle occurs without the fault recurring. |
| • | The Passlock module 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
| • | Use a scan tool in order to inspect the Passlock™ module data voltage and the Passlock™ module code. |
| • | Inspect the Passlock module sensor harness for an intermittent or a short to battery. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests for the proper operation of the Passlock battery voltage circuit.
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This step tests for a short to voltage in the Passlock battery voltage circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Theft Deterrent System Schematics | ||||
1 | Did you perform the Theft Deterrent (VTD) Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool display DTC B2948 as a current DTC? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
|
Important: The use of DMM J 39200 is crucial in this step because voltage may be interrupted for 10 milliseconds only.
Does the voltage measure near the specified value? | 0 V | Go to Step 7 | Go to Step 4 | |
Test the 12 V reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 5 | |
5 | Inspect for poor connections at the Passlock module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 |
6 | Inspect for poor connections at the Passlock™ sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 |
7 | Replace the Passlock™ module. Refer to Theft Deterrent Module Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
8 | Replace the Passlock™ sensor in the electronic column lock module assembly. Refer to Electronic Column Lock Module - Disassemble - Off Vehicle or Electronic Column Lock Module - Assemble - Off Vehicle in Steering Wheel and Column. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 | Perform the Programming Theft Deterrent System Components procedure. Is the repair complete? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
