Tailgate lock
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 BMW X3, 2016 BMW X3, 2015 BMW X3, 2014 BMW X3, and 2013 BMW X3. However, it is still accessible from the selected car via links, so may be relevant.
The tailgate lock is electrically unlocked (hotel setting not engaged) via the operating points (e.g. ID transmitter, interior tailgate button, exterior tailgate button). The rear electronic module (REM) operates the DC motor of the release drive in the tailgate lock, thereby unlocking the tailgate lock.
The front electronic module (FEM) is the master control unit. In other words, the front electronic module issues the enable for unlocking the tailgate lock.