B2781

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
When an ignition key is inserted in the ignition switch, the terminals located in the steering column lock cylinder contact the resistor pellet in the key. The IPC measures the resistance of the key pellet and then determines if the measured value matches the value stored in the IPCs memory. If a failure occurs in the wiring or the key pellet after the vehicle has been started, the vehicle enters fail-enable mode and allows the vehicle to be restarted on future attempts.

CONDITIONS FOR SETTING THE DTC
^ The IPC determines that one of the 15 valid key pellets was detected, and matches the resistance of the one stored in the IPCs memory.
^ The IPC class 2 vehicle security password report message was sent and acknowledged.
^ The IPC then determines that one of the 15 valid key pellets was detected, but now the key pellet does not match the resistance of the one stored in the IPCs memory.

ACTION TAKEN WHEN THE DTC SETS
The IPC displays the THEFT SYSTEM PROBLEM, CAR MAY NOT RESTART message on the driver message center.

DIAGNOSTIC AIDS
Before attempting to diagnose a wiring problem, try to start the vehicle with every available ignition key for the vehicle. If one key starts the vehicle and another key does not, replace the malfunctioning key with another key of the same code value as the key that starts the vehicle.