See also:

Switching off automatically
The system switches off and the LED goes out: After approx. 160 ft/50 m when driving forward. Above approx. 22 mph/36 km/h when driving forward. Switch on the system again if necessary. ...

Switching on automatically
Select transmission position R with the engine running. ...

The concept
The system issues a two-phase warning of a danger of collision at speeds above approx. 10 mph/15 km/h. The collision warning is available even if cruise control has been deactivated. It resp ...