See also:

Horn
Audible warning system to alert other road users to an imminent danger. Press the central part of the multifunction steering wheel. Use the horn moderately and only in the following circumstances: ...

Seat backrest angle
Push the control rearwards. ...

Operating fault
In the event of a malfunction of the system, when reverse gear is engaged this warning lamp is displayed in the instrument panel and/or a message appears in the screen, accompanied by an audible ...