See also:

Activating HDC
Press the button; the LED above the button lights up. ...

Fuel quality
Fuels that are marked on the gas pump as containing metal must not be used. Refuel only with unleaded gasoline without metallic additives. Do not refuel with any leaded gasoline or gasoline ...

Steering wheel heating
Switching on/off Switching on/off Press the button. ▷ On: the LED lights up. ▷ Off: the LED goes out. ...