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 ON position. |
| • | The Passlock is unable to produce the 12 volts to the Passlock sensor. This may be due to a module, a wiring, or a sensor problem. |
Action Taken When the DTC Sets
| • | The vehicle does not start if the fault occurs before you start the vehicle. The security indicator will be ON. |
| • | If the vehicle is running when the fault occurs, the Passlock will be in the fail enable mode allowing the vehicle to start and to run. The security indicator will be ON. |
Conditions for Clearing the MIL/DTC
| • | The DTC will clear after an ignition cycle occurs without the fault recurring. |
| • | The Passlock history code clears after 100 concurrent ignition cycles occur without the fault recurring. |
| • | Using a scan tool. |
Diagnostic Aids
| • | Use a scan tool in order to inspect the Passlock™ data voltage and the Passlock™ code. |
| • | Inspect the Passlock™ sensor harness for an intermittent or a short to ground. 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.
-
This step verifies the existence of this current DTC.
-
This step tests for a short to ground in the Passlock™ sensor or the pigtail harness.
-
This step tests for a short to ground in the 12 V reference 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 | |
Does the scan tool display DTC B2947 as a current DTC? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
Does the voltage measure within the specified range? | B+ | Go to Step 6 | Go to Step 4 | |
Test the 12 V reference circuit for a short to ground. 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 7 |
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 |
