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 body control module (BCM) provides security system sensor power and low reference for the Passlock™ 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™ 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 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.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2958 Security System Sensor Data Circuit High
Conditions for Setting the DTC
| • | The ignition switch is ON. |
| • | The BCM signal input is greater than 4.9 volts for one 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™ data voltage and the Passlock™ code. |
| • | Inspect the Passlock™ sensor harness for an intermittent or a short to battery. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | When directed to this table, DTC B2958 may have a history status. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests for proper operation of the circuit in the high voltage range.
-
This step tests for proper operation of the circuit in the low voltage range.
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This step tests for high resistance or an open in the 12-volt reference circuit.
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This step tests for a short to voltage, a high resistance, or an open in the signal circuit.
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This step tests for high resistance or an open in the ground circuit.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Immobilizer Schematics Connector End View Reference: Immobilizer Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the Passlock™ Data Voltage is within the specified range? | 0.4-4.9 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
Does the scan tool indicate that the Passlock™ Data Voltage is greater than the specified value? | 4.9 V | Go to Step 4 | Go to Step 9 | |
Does the scan tool indicate that the Passlock™ Data Voltage is less than the specified value? | 0.4 V | Go to Step 5 | Go to Step 7 | |
Does the voltage measure less than the specified value? | 12 V | Go to Step 6 | Go to Step 11 | |
6 | Test the 12-volt reference circuit of the Passlock™ sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9 |
Test the signal circuit of the Passlock™ sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 | |
Test the ground circuit of the Passlock™ sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9 | |
9 | Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
10 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
11 | Inspect for poor connections at the Passlock™ sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
12 | Replace the Passlock™ sensor in the ignition lock cylinder case. Refer to Ignition Lock Cylinder Case Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
13 | Perform the Programming Theft Deterrent System Components procedure. Is the repair complete? | -- | Go to Step 14 | -- |
14 |
Does the DTC reset? | -- | Go to Step 3 | Go to Step 15 |
15 | Attempt to start the vehicle. Does the engine start and run? | -- | System OK | Go to Step 3 |
