See also:

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

Observe the following when refueling
The fuel tank is full when the filler nozzle clicks off the first time. Handling fuels Obey safety regulations posted at the gas station.◀ ...

Switching on/off
Press the button. ...