Switching the split screen on and off
1. 
Press the button.
2. "Split screen"
See also:
Initialization after a power failure
After a power failure, it is only possible to raise
the roof, if necessary.
Have the system initialized by your service center. ...
Enabling operation in the rear
Only possible via the iDrive in the front.
1. "Settings"
2. "Allow rear control"
3. Select the desired priority.
...
xDrive*
xDrive is the all-wheel-drive system of your vehicle.
Concerted action by the xDrive and DSC
further optimize traction and driving dynamics.
The xDrive all-wheel-drive system variably distribute ...