System Self-Test

SYSTEM SELF-TESTS

A diagnostics mode is available in the system to verify operation of all monitored switches or circuits. To enter diagnostics, cycle the ignition key to the accessory position 3 times, leaving the key in this position.

Upon entering diagnostics, the park and tail lamps will begin flashing to verify their operation. In addition, the horn will sound twice to indicate its proper operation. Returning the ignition to the OFF position will stop the lamps from flashing while keeping the system in diagnostics.

While in diagnostics mode, a horn pulse should occur at each of the following events indicating proper operation:

(1) Beginning with both doors closed, open then close each door. The horn will sound when each door opens and again when closed. There must be a 1 second delay between closing and opening the switch. The door signal comes from the door latch/passive restraint mechanism.

(2) Using the headlamp switch, turn interior lamps ON. The horn will sound when turned ON and when turned OFF. There must be a 1 second delay between turning ON and OFF the switch.

(3) Cycle the key to the ignition RUN position. A single horn pulse will indicate proper operation of the ignition input. This will also take the module out of the diagnostics mode. For any of these tests, if the switch does not remain open or closed for at least 1 second, the horn will only sound once.

The lack of a horn pulse, during any operation, indicates a switch failure. Check for continuity at the switch, if this is good, check for an open or shorted wire between the switch and security module. Also, check if a new powertrain control module has been installed recently. Vehicle Theft Security System will not function until ignition switch is turned to the start (crank engine) position 20 times.

Whenever a Vehicle Theft Security System malfunction occurs, first verify that the wire harness is properly connected to all connectors before starting normal diagnosis and repair procedures.