Circuit Description
The Passlock™ system is designed in order to prevent vehicle operation if the correct ignition key is not used in order to start the vehicle. The ignition key allows the lock cylinder to turn. Once the lock cylinder turns, the Passlock™ sensor (located inside the ignition switch assembly) sends an analog voltage code to the body control module (BCM). If the BCM receives the correct analog voltage code from the Passlock™ sensor, the BCM sends a class 2 serial data password to the vehicle control module (VCM). This action allows the vehicle to start.
Conditions for Setting the DTC
The Passlock™ power circuit remains low (shorted to ground) for 1 second when the ignition switch is in the RUN position.
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. |
| • | The vehicle will continue to start if the fault occurs after the vehicle is running. The following conditions will exist: |
| - | The vehicle will be in the Fail Enable mode. |
| - | The security indicator will be ON. |
Conditions for Clearing the MIL/DTC
| • | All current DTC (except B3031) clears after an ignition cycle occurs without the fault recurring. |
| • | A history DTC clears 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 the ignition switch is turned from the OFF position to the RUN position, the security indicator will turn ON STEADY and then turn OFF after 3 seconds. |
| • | Perform a visual inspection of the wiring. |
| • | Perform a visual inspection of the connectors. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Verifies the existence of this current DTC.
-
Tests for a short to ground in the Passlock™ sensor or the wiring harness.
-
Tests for a short to ground in the 12v reference circuit.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
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 | |||||
Does the voltage measure within the specified range? | B+ | Go to Step 7 | Go to Step 4 | |||||
Test the 12v 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 BCM. 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 |
Important: Perform the set up procedure for the body control module . Replace the body control module. Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | -- | Go to Step 10 | -- | ||||
7 | 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 | ||||
8 | Replace the Passlock™ sensor in the lock cylinder housing assembly.
Did you complete the replacement? | -- | Go to Step 9 | -- | ||||
9 | Perform one of the following Passlock™ learn procedures:
Is the repair complete? | -- | Go to Step 10 | -- | ||||
10 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
