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 B3033 Security System Indicates Tamper
Conditions for Setting the DTC
| • | The BCM will inspect for a tamper code when the ignition switch rotates from ON to CRANK and will continue to monitor the signal during the engine running period. |
| • | The BCM is reading a tamper code from the Passlock™ sensor for longer than 1 second. |
Action Taken When the DTC Sets
| • | The vehicle will not run. The SECURITY indicator will be flashing. |
| • | The Passlock™ state is tamper. |
Conditions for Clearing the DTC
| • | The DTC will clear once an ignition cycle occurs without the fault recurring. |
| • | The BCM history codes will clear after 100 ignition cycles occur without the fault recurring. |
| • | Use a scan tool |
Diagnostic Aids
| • | Prior to replacing a BCM, ensure that all of the diagnostics have been completed. Refer to Diagnostic Trouble Code (DTC) List - Vehicle . |
| • | Inspect the Passlock™ sensor harness for intermittent or poor connections. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | The vehicle theft deterrent (VTD) internal diagnostics are not run while the tamper timer is active. |
Test Description
The number below refers to the step number on the diagnostic table:
Step | Action | 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 |
Important: Do not start the vehicle. Does the scan tool display DTC B3033 as a current DTC? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections |
Inspect the area around the ignition lock cylinder for any device which could create a magnetic field audio speaker, magnet, etc. Is there a magnetic device near the ignition lock cylinder? | Go to Step 4 | Go to Step 5 | |
4 | Remove the device creating the magnetic force. Did you complete the repair? | Go to Step 8 | -- |
5 | 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 8 | Go to Step 6 |
6 | Replace the Passlock™ sensor in the electronic column lock module assembly. Refer to Ignition Lock Cylinder Case Replacement . Did you complete the replacement? | Go to Step 7 | -- |
7 | Perform the learn procedure. Refer to Immobilizer System Component Programming. Is the repair complete? | Go to Step 8 | -- |
8 |
Important: You may have to wait up to 10 minutes in order to reset the body control module (BCM) and synchronize all of the Passlock™ components.
Important: Do not start the vehicle. Does the DTC reset? | Go to Step 3 | System OK |
