Description And Operation: Anti-Theft: 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).

NOTE: The convertible top (if equipped), the luggage compartment lid, and all doors must be closed for the interior motion sensing feature to activate.

NOTE: The perimeter alarm system includes a motion detection system that monitors the vehicle interior and a vehicle inclination sensor that detects changes in vehicle inclination.

NOTE: The inclination sensing feature must be disarmed before raising the vehicle on a hoist to prevent false alarms.

The perimeter alarm system consists of:

Anti-theft hood switch (located in the right front corner of the engine compartment)
Convertible top ajar switch (if equipped) (located behind the RH side of the rear seat)
Door ajar switches (part of the door latch)
Door disarm switch (driver door only) (part of the door latch)
Door lock control switch
Intrusion and inclination sensor (located in the overhead console)
Luggage compartment lid ajar switch (part of the luggage compartment lid latch)
Remote Keyless Entry (RKE) transmitter
Traffic horn
Body Control Module B (BCM-B)
SJB

The anti-theft perimeter alarm feature is controlled by the SJB. The perimeter alarm system is designed to warn the driver in the event of an unauthorized entry to the vehicle and is also designed to help prevent the unwanted towing of the vehicle. When the vehicle is locked and armed, the perimeter alarm system monitors the following:

Doors
Hood
Luggage compartment lid
Movement inside the vehicle
Variations in vehicle inclination/tilt

If an unauthorized activation of the above inputs occurs (an activation occurring with the system armed), the system flashes the turn signals and sounds the traffic horn.

The interior motion detection and vehicle inclination sensing systems operate only when the vehicle is locked using the RKE transmitter or when using the door lock control switch with the accompanying door open and both doors are then closed. For vehicles with a convertible top, the top must be fully closed and latched for the interior motion sensing system to arm. If the vehicle is locked using the key in the driver door lock cylinder, the system monitors the doors, the luggage compartment lid and the hood, but the interior motion and the vehicle inclination sensing does not arm. If necessary, the vehicle inclination sensing and the interior motion sensing features will not arm if both doors are locked using the manual push buttons, then closing the door, or using the manual push button on the passenger door and then locking the driver door with the key in the door lock cylinder. The former step will not cause any part of the perimeter alarm to be armed, while the latter step arms the perimeter alarm, but not the interior motion and vehicle inclination sensing features. For correct operation of the interior motion detection system, all the windows must be closed prior to arming the system. This prevents accidental alarm activation due to external influences and makes sure that correct interior motion detection occurs. The interior motion sensing system does not arm if either door is ajar.

The BCM-B sends a message over the local interconnect network to the intrusion and inclination sensor to disarm if the SJB is commanded to open the luggage compartment lid, or open a window or unlock the door locks. If any of these events occurs, the SJB sends a message over the Medium Speed Controller Area Network (MS-CAN) to the BCM-B, which signals the intrusion and inclination sensor to disarm.