Operation CHARM: Car repair manuals for everyone.

B2960

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 combinations. The BCM will only recognize the last learned valid code.

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

CONDITIONS FOR SETTING THE DTC
^ The BCM will inspect for a valid code when the ignition is rotated from ON to CRANK and will continue to monitor the signal during the engine running period.
^ The BCM is reading a valid but different code value than previously learned from the Passlock sensor.

ACTION TAKEN WHEN DTC SETS
^ If the DTC sets during cranking, the car will not start or will start with the theft indicators illuminated.
^ If the DTC sets while the engine is running, the car will start on future attempts and the theft indicators is illuminated.
^ The SERVICE VEHICLE SOON indicators 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
^ This DTC will not set if the BCM is in learn mode.
^ Inspect for a poor connection at the Passlock sensor and BCM.
^ If the DTC is a history DTC, the problem may be intermittent. Perform the tests 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:
6. Tests for the proper operation of the circuit in the normal voltage range.