Battery Back Up Sounder (BBUS)

WARNING: This page is about a different car, the 2018 Jaguar XE and 2017 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If a BBUS is fitted, it is also armed with the perimeter mode lock request. However, the tilt functionality is not enabled in perimeter mode.

On receipt of the arming signals, the BBUS and the tilt sensor respond with a status message. If the BCM/GWM does not receive the status signals within a period of time, the BCM/GWM assumes there is a fault and responds with a disarm signal to either the sounder and/or the tilt sensor and stores a related fault code. If the sounder is disarmed when the active anti-theft system is armed and the system is subsequently triggered, the CJB still energizes the horn relay and uses the vehicle horns to sound the audible warning in place of the sounder.

When the sounder is armed, the BCM/GWM sends a periodic (heartbeat) signal to the sounder which prompts the sounder to monitor the vehicle battery supply and the LIN bus link with the BCM/GWM. The sounder will operate if:

It receives an alarm signal from the BCM/GWM or the tilt sensor.
The power supply or the LIN bus link to the BCM/GWM is disrupted.

The tilt sensor measures the longitudinal and lateral angle of the vehicle over a range of ±16 degrees from the horizontal. When the active anti-theft system is armed in volumetric mode, the tilt sensor stores the current vehicle angles in its memory and monitors the tilt sensor readings. If the vehicle angle changes in either direction by more than the alarm limit threshold, the tilt sensor communicates to the BCM/GWM in order to activate the alarm sounder.

If the alarm system is active and the battery or the BBUS is disconnected, the BBUS will continue to sound without the visual indication of the turn signal indicators flashing.