CITROËN DS 5 Handbook page 136

Switching on
F Turn the wheel 1 to the "cRUISE" position
to select cruise control mode; the function
is paused.
F To start the cruise control and set a cruise
speed, once the vehicle has reached the
desired speed, press button 2 or 3: the
current speed of your vehicle becomes the
cruise speed setting.
You can release the accelerator pedal.
F Pressing button 4 interrupts operation of
the system (pause).
F Pressing button 4 again restores operation
of the cruise control (ON).
Adjusting the cruise speed
setting
The cruise control must be activated.
To modify the cruise speed setting using
memorised speeds and from your Audio
system:
F with the system first activated.
For more information on memorising speeds,
refer to the corresponding section.
F make a long press on button 2 or 3, the
system displays the memorised speed
closest to the actual speed of the vehicle;
this setting becomes the new cruise speed,
F to choose another memorised speed, make
another long press on button 2 or 3.
To modify the cruise speed setting using
memorised speeds and from the touch screen:
F press button 5 to display the six memorised
speed settings,
F press the button for the desired speed
setting.
This setting becomes the new cruise speed.
As a precaution, it is recommended
that the cruise speed chosen be close
to the current speed of your vehicle, so
as to avoid any sudden acceleration or
deceleration of the vehicle.
To modify the cruise speed setting from the
current speed of the vehicle:
F in steps of + or - 1 mph (km/h), make
repeated short presses on button 2 or 3,
F continuously, in steps of + or - 5 mph
(km/h), press and hold button 2 or 3.
Take care: pressing and holding
button 2 or 3 results in a rapid change
in the speed of your vehicle.