B2958

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The body control module (BCM) will read an analog voltage form the Passlock 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 combination. The BCM will only recognize the last learned valid code.

CONDITIONS FOR RUNNING THE DTC
The ignition switch is cycled to CRANK and released to ON.

CONDITIONS FOR SETTING THE DTC
^ The ignition switch is ON.
^ The 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
^ If the DTC sets during cranking, the car will not start and the theft indicator is on continuously.
^ If the DTC sets while the engine is running, the car will start on future attempts.
^ The SERVICE VEHICLE SOON indicator illuminates.

CONDITIONS FOR CLEARING THE DTC
^ Current DTCs will clear after one ignition cycle if the malfunction is no longer present.
^ All of the BCM history codes will be cleared after 100 ignition cycles (from OFF to ON) with no current codes active during the 100 ignition cycles.

DIAGNOSTIC AIDS
^ If the malfunction occurred during engine crank, this DTC may not set.
^ Inspect for a poor connection at the Passlock(R) sensor and BCM.
^ If the DTC is a history DTC, the problem may be intermittent. Perform the test shown while wiggling the wiring and connectors. This will cause the malfunction to appear.

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 sensor signal circuit.