Principles of Operation
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The perimeter anti-theft feature provides an audible and visual alarm when unauthorized access to the vehicle is detected. When an intrusion is detected by any door ajar, liftgate ajar, hood or luggage compartment switches, it sends a signal to the smart junction box (SJB). When the SJB receives a signal indicating intrusion into the vehicle, the SJB supplies a signal to the horn control relay and the parking lamps relay. The relays close, supplying the voltage which activates the horn and the parking lamps. The perimeter anti-theft feature does not arm until 20 seconds elapse after locking the vehicle. The perimeter anti-theft device disarms only when:
- unlock is pressed on the remote keyless entry (RKE) transmitter.
- the RKE keypad code is entered.
- the driver door lock cylinder is turned to unlock.
- the ignition switch position changes to RUN or START.