B2957

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The body control module (BCM) will read an analog voltage from the Passlock(TM) sensor. Based on an internal reference, the BCM will determine if the measured voltage is in one of the following conditions:
^ Open
^ Shorted to ground A valid code
^ A tamper code

There are 10 possible valid code combinations. The BCM will only recognize the last learned valid code.

CONDITIONS FOR SETTING THE DTC
^ The ignition switch is ON.
^ The 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 telltale 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 telltale 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
^ When replacing the Passlock(TM) sensor, all of the following components are included as a replacement part and must be replaced:
- The lock
- The sensor
- The filter
- The harness
^ 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 battery. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
^ Following a repair the tamper timer needs 10 minutes in order to expire.

TEST DESCRIPTION
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.