CITROEN DS3 Handbook page 110

Parking brake
Applying
F Pull the parking brake lever fully up to
immobilise your vehicle.
Releasing
F Pull the parking brake lever gently, press
the release button then lower the lever
fully.
When the vehicle is being driven, if this
warning lamp and the STOP warning
lamp come on, accompanied by an
audible signal and a message in the multifunction
screen, this indicates that the parking brake is still
on or has not been properly released.
When parking on a slope, direct your
wheels against the pavement, apply the
parking brake and engage a gear.