B2957

DTC B2957

CIRCUIT DESCRIPTION




The Passlock(TM) system is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock(TM) controller reads the coded Passlock(TM) data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock(TM) assembly and the Passlock(TM) 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 over the class 2 bus to indicate that starter engagement should be allowed. The Passlock(TM) controller also interfaces with the driver displays subsystem to indicate, via a Security telltale, the Passlock(TM) subsystem's status and acute subsystem failures.

CONDITIONS FOR SETTING THE DTC
- The ignition switch is ON.
- The body control module (BCM) signal input is less than 0.4 volts for 1 second after turning the ignition switch to the CRANK position.

ACTION TAKEN WHEN THE DTC SETS
- The vehicle will not start if the fault occurs before you start the vehicle. The security indicator will flash for 10 minutes then turn ON steady.
- If the vehicle is running when the fault occurs, 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 DTC will clear once the ignition cycle has occurred without the fault recurring.
- The BCM history codes will clear once 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(TM) data voltage and the Passlock(TM) code.
- Inspect the Passlock(TM) sensor harness for an intermittent or a short to ground. refer to Diagnostic Aids for Circuit Testing and Wiring Repair procedures.
- Following a repair the tamper timer needs 10 minutes in order to expire.

TEST DESCRIPTION

Steps 1-10:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for proper operation of the circuit in the high voltage range.
4. Tests for a short to ground in the Passlock(TM) sensor signal circuit.