CITROEN DS3 Handbook page 151

Horn
Audible warning to alert other road users to an
imminent danger.
F Press one of the spokes of the steering
wheel.
Emergency or
assistance call
This system allows you to make an emergency
or assistance call to the emergency services
or to the dedicated service (operated by
CITROËN Assistance).
For more information on the use of this
function, refer to the "Audio and telematics"
section.
149
Safety