CITROËN DS4 Owner's Handbook Manual page 217

Blind spot sensors
This driving assistance system warns the driver
of the presence of another vehicle in the blind
spot angle of their vehicle (areas masked from
the driver's field of vision), as soon as this
presents a potential danger.
This system is designed to improve safety when driving and is in no circumstances a
substitute for the use of the interior rear view mirror and door mirrors. It is the driver's
responsibility to constantly check the traffic, to asses the distances and relative speeds of
other vehicles and to predict their movements before deciding whether to change lane.
The blind spot sensor system can never replace the vigilance and responsibility of the
driver.
A warning lamp appears in the door mirror on
the side in question:
- immediately, when being overtaken,
- after a delay of about one second,
when overtaking a vehicle slowly.
Operation
On switching on the ignition, or engine
running, press this button to activate the
function; the warning lamp comes on.
Sensors fitted in the front and rear bumpers
monitor the blind spots.
215
Driving