CITROËN DS5 Owner's Handbook Manual page 142

Reversing camera
A reversing camera is activated automatically
when reverse gear is engaged.
The colour image is provided in the navigation
screen.
This system is a driving aid that does not
replace the vigilance or the responsibility of the
driver, who must remain in control of the vehicle
at all times.
The green lines represent the general direction
of the vehicle.
The red lines represent around 30 cm beyond
the limit of your vehicle's rear bumper. The
audible signal becomes continuous from this
limit.
The blue lines represent the maximum turning
circle.
Clean the reversing camera regularly
using a sponge and a soft cloth.
When cleaning the vehicle with a high
pressure jet wash, keep the end of the
lance at least 30 cm from the camera.