See also:

Active seat
Active adjustment of the seat cushion's contours reduces muscular tension and fatigue to help prevent lower back pain. Press the button. The LED lights up. ...

Functional readiness of the airbag system
When the ignition is switch on, the warning lamp in the instrument cluster lights up briefly and thereby indicates the operational readiness of the entire airbag system and the belt tensione ...

Deactivating HDC
Press the button again and the LED goes out. HDC is automatically deactivated above approx. 37 mph/60 km/h. ...