See also:

Malfunction
A Check Control message is displayed. The parking assistant failed. Have the system checked. ...

Switching on automatically
With the engine running or the ignition switched on, shift the selector lever into position R. The image of the rear view camera is displayed when the system has been switched on using iDrive. ...

Deleting the button assignments
1. Press buttons 1 and 8 simultaneously for approx. five seconds. 2. "OK" ...