See also:

Malfunction
A message is displayed in the instrument cluster. HDC is not available, e.g., due to elevated brake temperatures. ...

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

For better control
The indicator lamp flashes: DSC controls the drive forces and brake forces. The indicator lamp lights up: DSC and DTC has failed. DSC deactivated: The indicator lamp lights up and DSC O ...