DTMF suffix dialing
DTMF suffix dialing can be used for gaining access to network services or for controlling devices, e.g., to make a remote inquiry of an answering machine. The DTMF code is needed for this purpose.
1. "Telephone".
2. Select the contact from a list or "Dial number".
3. 
"Keypad dialing".
4. Enter the DTMF code via iDrive.
See also:
Opening/closing the glass sunroof
When the sliding visor is open, proceed as described
under Sliding visor. ...
Adjusting the volume
Turn the knob until the desired volume is selected.
The setting is stored for the remote control
currently in use.
The vehicle automatically adjusts the volume of
the microphone on the telephone ...
Switching off
The system can be deactivated as follows:
▷ Press the button.
▷ Switch off the ignition. ...