2021 CITROEN C4 AIRCROSS sensor

81
In order for these systems to be fully effective, follow the operation and maintenance
guidelines below:
F
T
o obtain an even air distribution, take care not to obstruct the exterior air intake grilles
located at the base of the windscreen, the nozzles, the vents and the air outlets, as well
as the air extractor located in the boot.
F

D
o not cover the sunshine sensor, located on the dashboard; this is used for regulation
of the air conditioning system.
F

O
perate the air conditioning system for at least 5 to 10 minutes, once or twice a month
to keep it in per fect working order.
F

E
nsure that the passenger compartment filter is in good condition and have the filter
elements replaced regularly.
W

e recommend the use of a combined passenger compartment filter. Thanks to its
special active additive, it contributes to the purification of the air breathed by the
occupants and the cleanliness of the passenger compartment (reduction of allergic
symptoms, bad odours and greasy deposits).
F

T
o ensure correct operation of the air conditioning system, you are also advised to have
it checked regularly as recommended in the maintenance and warranty guide.
F

I
f the system does not produce cold air, switch it off and contact a CITROËN dealer or a
qualified workshop.
Recommendations for ventilation and air conditioning
If after an extended stop in sunshine,
the interior temperature is very high, first
ventilate the passenger compartment for
a few moments.
Put the air flow control at a setting high
enough to quickly change the air in the
passenger compartment.
The air conditioning system does not
contain chlorine and does not present
any danger to the ozone layer.
The condensation created by the air
conditioning results in a discharge
of water under the vehicle which is
per fectly normal.
When towing the maximum load on a steep gradient in high temperatures, switching off the
air conditioning increases the available engine power and so improves the towing ability.
3
C

114
The tyre under-inflation detection
system is an aid to driving which does
not replace the need for vigilance on
the part of the driver.
Under-inflation detection
System which continuously and automatically checks the pressures of the four tyres after switching on the ignition.
A pressure sensor is located in the valve of each tyre (except the spare wheel).
The system triggers an alert if a drop in pressure is detected in one or more tyres, compared to the reference pressure registered in the system.
This reference pressure must be reinitialised every time the tyre pressures are adjusted or a wheel changed.
The system operates on condition that sensor identifiers have first been memorised in the system by a CITROËN dealer or a qualified workshop.
You can memorise two sets of tyres (for example: wheels with "standard" tyres and wheels with "winter" tyres).
Driving with under-inflated tyres
increases fuel consumption.This system does not avoid the need
to check the tyre pressures regularly
(including the spare wheel) and before
a long journey.
Driving with under-inflated tyres
adversely affects road holding,
extends braking distances and causes
premature tyre wear, particularly under
arduous conditions (vehicle loaded,
high speed, long journey).
The tyre pressures for your vehicle can
be found on the tyre pressure label (see
the "Identification markings" section).
The tyre pressures must be checked
when the tyres cold (vehicle stopped
for 1 hour or after driving for less then
6 miles (10 km) at moderate speed).
Other wise, add 0.3 bar to the values
indicated on the label.
driving

115
Under-inflation alert
The alert is given by the fixed
illumination of this warning lamp and
the display of a message.
F

R

educe speed, avoid sudden steering
movements or harsh brake applications.
F

S

top as soon as it is safe to do so. The loss of pressure detected does not
always lead to visible deformation of the
tyre. Do not rely on just a visual check. The alert is maintained until the
reference pressure is reinitialised after
the inflation, repair or replacement of
the tyres concerned. In the event of
the repair or replacement of tyres, the
sensor identifiers must be registered in
the system by a CITROËN dealer or a
qualified workshop.
The spare wheel does not have
a sensor, so there is no need to
reinitialise the the system for running
with the spare wheel fitted.
F
I f you have a compressor (the one in the
temporary puncture repair kit for example),
check the four tyre pressures when cold.
I

f it is not possible to check the tyre
pressures at the time, drive carefully at
reduced speed.


or
F

I
n the event of a puncture, use the
temporary puncture repair kit or the spare
wheel (according to equipment).
Reinitialising the reference
pressure
Before reinitialising the system, ensure
that the pressures in the four tyres are
suitable for the conditions of use of the
vehicle and as specified on the tyre
pressure label.
The under-inflation detection system
cannot warn of an incorrect pressure at
the time of reinitialisation.
The system must be reinitialised after any
adjustment of tyre pressures and after
changing one or more wheels.
4
Driving

116
The reinitialisation instruction is entered in
the screen menu, with the ignition on and the
vehicle stationary.
F Press repeatedly on the INFO button
to select "REINITIALISE" (located in
menu
2/3 or 3/3 depending on the
instrument panel) .
F

P
ress and hold the INFO button for at least
3 seconds to reinitialise the under-inflation
detection system.
Reinitialisation of the system is confirmed
by the flashing of the warning lamp in the
instrument panel. The under-inflation alert is only reliable
if the system has been reinitialised
with the four tyre pressures correctly
adjusted.
Operating fault
The flashing and then fixed illumination of the
under-inflation warning lamp accompanied by
the display of a message indicates a fault with
the system.
In this case, monitoring of the tyre pressures is
not assured.
This alert is also displayed if:
-

o
ne or more wheels is not fitted with a
sensor (spare wheel in use),
-

a w
ireless device operating on the same
frequency is close to the vehicle,
-

t
here are accumulations of snow or ice in
the wings or wheels,
-

t
he state of charge of the tyre pressure
monitoring system battery is too low,
-

t
he wheel sensor identifiers have not been
memorised in the system by a CITROËN
dealer or a qualified workshop. Any tyre repair or replacement on a
wheel fitted with this system must be
carried out by a CITROËN dealer or a
qualified workshop.
If you fit the second set of tyres
memorised in the system, a fault will
be signalled until the second set is
selected in the configuration menu. Go to a CITROËN dealer or a qualified
workshop
to have the system checked
or, following the repair of a puncture, to
have the original wheel, equipped with a
sensor, refitted.
Driving

123
Parking sensors
This function cannot, in any
circumstances, take the place of the
vigilance and responsibility of the driver.
Rear parking sensors
This system indicates the proximity of an
obstacle (person, vehicle, tree, gate, etc.)
which comes within the field of detection of
sensors located in the bumper.
Certain types of obstacle (stake, roadworks
cone, etc.) detected initially will no longer be
detected at the end of the manoeuvre due to
the presence of blind spots.
Audible assistance
The proximity information is given by an
intermittent audible signal, the frequency of
which increases as the vehicle approaches the
obstacle.
When the distance between the vehicle and
the obstacle becomes less than approximately
thirty centimetres, the audible signal becomes
continuous.
The system is switched on by engaging reverse
gear. This is accompanied by an audible signal.
The indicator lamp in the button comes on to
confirm that the system is active.
The system is deactivated when you come out
of reverse gear.
4
driving

125
Visual assistance
Front parking sensors
Deactivation / Activation of the
front and rear parking sensors
The function is deactivated by pressing this
button. The indicator lamp in the button
goes off.
Pressing this button again reactivates the
function. The indicator lamp in the button
comes on.
Operating fault
The front parking sensors are triggered when
an obstacle is detected in front, a gear is
engaged (position D for vehicles with a CVT
gearbox) and the speed of the vehicle remains
below 6 mph (10 km/h).
The front parking sensors are interrupted if
the vehicle stops for more than five seconds
in for ward gear, if no further obstacles are
detected or when the speed of the vehicle
exceeds 6 mph (10 km/h). Remember to deactivate the system if
towing a trailer or caravan.In bad weather or in winter, ensure that
the sensors are not covered with mud,
ice or snow.
When the vehicle is moving at a speed
below 6 mph (10 km/h), certain sound
sources (motorcycle, lorry, pneumatic
drill, etc.) may trigger the audible
signals of the parking sensor system.
In the event of an problem, when reverse gear
is engaged this lamp in the button flashes,
accompanied by an audible signal.
This supplements the audible
signal by displaying bars in the
screen, in front of or behind
the vehicle.
If one of the sensors is faulty, it
flashes in the instrument panel
screen.
Contact a CITROËN dealer or a qualified
workshop.
These bars flash at the start of the manoeuvre
then become fixed from a certain distance
between the vehicle and the obstacle.
4
Driving

126
Reversing camera
Linked with the navigation option, the reversing
camera complements the parking sensor
system and is activated automatically when
reverse gear is engaged.The image from the camera is displayed in the
navigation screen.
The zone (A)


represents the upper part of the
rear bumper.
The red line represents the distance of 50 cm
from the edge of the rear bumper.
The green lines represent the width of the
vehicle increased by 20 cm on each side.
The marks on the green lines correspond to the
edges of the rear bumper (B), then the distance
of 1 metre from the edge of the rear bumper (C)
and 2 metres (D) . In no circumstances can the reversing
camera replace the need for vigilance
on the part of the driver.
Clean the reversing camera from time
to time using a soft dry cloth.
High pressure jet wash
When washing your vehicle, do not
direct the lance to within 30 cm of the
camera lens.
driving

130
In foggy weather or in snow, the
sunshine sensor may detect sufficient
light. The lighting will not come on
automatically.
do n
ot cover the sunshine sensor, the
associated functions will no longer be
controlled.
Automatic switching off
When the lighting control stalk is at "dipped or
main beam headlamps", if the ignition switch
is at "LOCK" or "ACC" or if the key has been
removed from the ignition switch, the lamps
switch off automatically when the driver's
door is opened .
Daytime running lamps
Daytime lighting which comes on automatically
when the engine is started making the vehicle
more visible to other users.
This function is assured by special lamps.
The lighting control stalk must be placed in
position "0" or "AUTO" (day mode).
Automatic illumination of headlamps
The sidelamps and the dipped beam headlamps
come on automatically, without any action on the
part of the driver, if a low level of exterior light is
detected or if the wipers are switched on.
When the light returns to a sufficient level or the
wipers are switched off, the lighting is switched off
automatically.
The sensor is located at the base of the windscreen.
Contact a CITROËN dealer or a qualified workshop
to adjust the sensitivity of the sensor.
Visibility