See also:

Cleaning the brake discs
Coatings of dirt and water on the brake discs may result in delayed brake function. This delay is minimized by cleaning the brake linings. Cleaning the brake pads is advisable in wet weather, prior ...

Low battery voltage
If the battery voltage is too low, the parking brake cannot be applied or released. Connect an auxiliary battery if the battery voltage is too low, see page 114. ...

Disconnecting the cell phone
The cell phone is automatically disconnected from the infotainment system if it is moved out of range. The cell phone can be manually disconnected from the hands-free system by pressing and holdi ...