Principles of Operation: Notes

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

When the perimeter alarm is armed, the SJB monitors the door ajar switches, the hood switch, the luggage compartment lid ajar switch, and the Body Control Module B (BCM-B) sends a message over the local interconnect network to arm the intrusion and inclination sensor.

If any intrusion is detected without the alarm being deactivated, the SJB activates the perimeter alarm and sounds the horn and flashes the turn signals in regular intervals.

The system arms when:

the driver door is locked with the key in the door lock cylinder (which does not activate the intrusion or inclination systems)
the doors are locked with the Remote Keyless Entry (RKE) transmitter (this arms the entire system)
the doors are locked with the door lock control switch (with the door open) and then the accompanying door is closed (this also arms the entire system)
If the doors are locked using the manual push buttons, no part of the perimeter alarm is armed. The SJB monitors the status of all entry points. If any entry point is open, the alarm arms everything except for the open entry point. The SJB adds the entry point to the protected status when the closure of the open entry point is detected. Note that only when the system is armed by locking the door using the key in the door lock cylinder is there no intrusion/inclination protection. Arming the system (locking the doors) using the RKE transmitter or using the door lock control switch allows the intrusion/inclination protection to also arm.

NOTE: The intrusion sensing feature is not activated if either door or the convertible top (if equipped) is open when the vehicle is armed.

The SJB inhibits the intrusion and inclination sensor and the luggage compartment lid ajar inputs if the luggage compartment lid is opened with the RKE transmitter. Once the luggage compartment lid is closed, the intrusion and inclination sensor and the luggage compartment lid ajar switch are monitored by the SJB.