Circuit Description
The Passlock™ system is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock™ controller reads the coded Passlock™ data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock™ assembly and the Passlock™ controller. If the data is correct , indicating rotation of the lock cylinder with the proper mechanically cut key, then the Passlock™ controller sends a password to the Powertrain controller via serial data to indicate that engine starting should be allowed. The Passlock™ controller also interfaces with the driver displays subsystem to indicate, via the security indicator, the Passlock™ subsystems status and acute subsystem failures.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2928 Security System Sensor Data Circuit High
Conditions for Setting the DTC
| • | The ignition switch is ON. |
| • | The body control module (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™ 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 . |
| • | 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
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for a short to voltage on the 5-volt reference circuit from the BCM.
-
This step tests for a short to voltage on the off/run/crank voltage circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Immobilizer Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Is the 5-volt reference circuit voltage greater than the specified value? | 5 V | Go to Step 4 | Go to Step 3 | |
Important: Do not start the vehicle. Is the voltage measured at the off/run/crank voltage circuit near the specified value? | 5 V | Go to Step 5 | Go to Step 6 | |
4 | Inspect the 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6 |
5 | Inspect the off/run/crank voltage circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7 |
6 | 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 11 | Go to Step 8 |
7 | Inspect for poor connections at the ignition switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9 |
8 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
9 | Replace the ignition switch. Refer to Ignition and Start Switch Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Perform the Immobilizer System Component Programming procedure. Is the repair complete? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
