System Operation Check

NOTE: Vehicles equipped with the Vehicle Theft Security System are also equipped with Illuminated Entry. Therefore, when in diagnostic mode, it is recommended that the Illumination Entry Module be removed, otherwise it is necessary to wait for the 30 second delay after each door opening or closure.

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

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

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

Beginning with all the doors closed, open then close each door. The horn will sound when the door ajar switch closes, and then again when the switch opens. There must be a one second delay between closing and opening the switch.
Open, then close the hood. The horn will sound when the hood is opened, and again when it is closed.
Activate the power door locks in both the Lock and Unlock directions. The horn will sound after each activation.
Rotate the key in each of the door lock cylinders to the unlock position. The horn will sound as the switch closes, and again when it opens. There must be a 1 second delay between changing switch states, or the horn will not sound.
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.

During 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, the lack of that input to the Vehicle Theft Security System module, or a failure internal to the module. Check for continuity at the switch. If the switch is good, check for an open or shorted wire between the switch and alarm module. Also, check if the engine controller has been replaced recently. For the first 20 engine starts with a new SBEC, the Vehicle Theft Security System will function normally except it will not prevent the engine from starting and running.

NOTE: A functional engine controller that has been used in a vehicle equipped with Vehicle Theft Security System cannot be used in another vehicle that is not equipped with the Vehicle Theft Security System. If the Security Lamp comes on after ignition switch is turned to ON position and stays on, the CCD bus communication with the engine controller has been lost.