Principles of Operation: Notes
WARNING: This page is about a different car, the 2013 Ford Fiesta. However, it is still accessible from the selected car via links, so may be relevant.
The Body Control Module (BCM) controls the operation of the perimeter alarm based on the following inputs:
- door ajar switches
- hood ajar
- driver door lock cylinder
- door lock control switch
- Passive Anti-Theft System (PATS) input
- and the Remote Keyless Entry (RKE) transmitters
On vehicles equipped with Intelligent Access (IA) the BCM receives the RKE transmitter and IA input from the Remote Function Actuator (RFA) module over the Medium Speed Controller Area Network (MS-CAN). If the perimeter alarm is armed, and the BCM receives an input indicating an unauthorized entry into the vehicle or the ignition is turned to the RUN position without a programmed PATS key, the BCM activates the perimeter alarm. When the perimeter alarm is activated, the anti-theft horn sounds and the turn signals flash in regular intervals. The traffic horn does not sound during a perimeter alarm event.