CITROËN DS4 Owner's Handbook Manual page 111

Anti-intrusion security
This system allows automatic simultaneous locking of the doors and boot as soon as the speed of the vehicle exceeds 6 mph (10 km/h).
Operation
If one of the doors or the boot is open,
the automatic central locking does not take
place.
This is signalled by the sound of the
locks rebounding, accompanied by
illumination of this warning lamp in
the instrument panel, an audible signal
and the display of an alert message.
Carrying long and voluminous
objects
If you want to drive with the boot open,
you should press the central locking
button to lock the the doors. Otherwise,
every time the speed of the vehicle
exceeds 6 mph (10 km/h), the locks
will rebound and the alerts mentioned
above will appear.
Pressing the central locking button unlocks
the vehicle.
Above 6 mph (10 km/h), this locking is
temporary.
Activation/Deactivation
You can activate or deactivate this function
permanently.
With the ignition on, press this button
until an audible signal starts and a
corresponding message is displayed.
The state of the system stays in memory when
switching off the ignition.
In the event of a serious impact with
deployment of an airbag, the vehicle's
doors unlock automatically to allow
the exit of occupants and access for
the security services.
109
Access