See also:

For 520i and 528i: Check oil level
The concept The oil level is monitored electronically during driving and shown on the Control Display. If the oil level reaches the minimum level, a check control message is displayed. Displayi ...

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. ...

Tone control
You can alter various tone settings, e.g. treble and bass or the speed-dependent volume increase. The tone settings are applied to all audio sources. The settings are stored for the remote control ...