61 13... Inline plugs, 3-, 6-pin, System Elo-Power 2.8
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2016 BMW 328i xDrive, 2016 BMW 328d xDrive, 2015 BMW 328i xDrive, 2015 BMW 328d xDrive, and 2014 BMW 328i xDrive. However, it is still accessible from the selected car via links, so may be relevant.
Press locking hook (1) in direction of arrow and disengage. Then unlock locking hook (2) and remove lock.
Press down retaining hook with screwdriver (1) and pull out cable with contact towards rear.