sensor CITROEN C5 2021 User Guide
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6Towing
Driving with a trailer places greater 
demands on the towing vehicle and 
particular care must be taken.
Do not exceed the maximum towable 
weights.
At altitude: reduce the maximum load by 
10% per 1,000 metres of altitude; the lower 
air density at high altitudes decreases engine 
performance.
New vehicle: do not tow a trailer until the 
vehicle has driven at least 620 miles 
(1,000 kilometres).
If the outside temperature is high, let the 
engine idle for 1 to 2 minutes after the 
vehicle comes to a stop, to help it to cool.
Before setting off
Nose weight
► Distribute the load in the trailer so that the 
heaviest items are as close as possible to the 
axle and the nose weight (at the point where it 
joins your vehicle) approaches the maximum 
permitted without exceeding it.
Tyres
► Check the tyre pressures of the towing 
vehicle and of the trailer , observing the 
recommended pressures.
Lighting
► Check the electrical signalling on the trailer 
and the headlamp beam height of your vehicle.
If a genuine CITROËN towing device is 
used, the rear parking sensors will be 
deactivated automatically to avoid the audible 
signal.
When driving
Cooling
Towing a trailer uphill causes the coolant 
temperature to increase. The maximum towable 
load depends on the gradient and the exterior 
temperature. The fan’s cooling capacity does not 
increase with engine speed.
►
 
Reduce speed and lower the engine speed to 
limit the amount of heating produced.
►
 
Pay constant attention to the coolant 
temperature.
If this warning lamp and the STOP 
warning lamp come on, stop the 
vehicle and switch off the engine as soon as 
possible.
Brakes
Using the engine brake is recommended to limit 
the overheating of the brakes. Braking distances 
are increased when towing a trailer.
Side wind
Bear in mind that the vehicle will be more 
susceptible to wind when towing.
Anti-theft protection
Electronic immobiliser
The keys contain a code, which must be 
recognised by the vehicle before starting is 
possible.
If the system malfunctions, indicated by the 
display of a message, the engine will not start.
Contact a CITROËN dealer.
Starting/Switching off the 
engine with Keyless Entry 
and Starting
The electronic key must be present in the  passenger compartment.
If the electronic key is not detected, a 
message is displayed.
Move the electronic key so that the engine 
can be started or switched off.    
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coming out of reverse gear or turning the 
steering wheel.
Restarting the engine (START mode)
The engine automatically restarts as soon as the 
driver indicates the intention of moving off again:
– 
With the selector in mode 
 D or M: with the 
brake pedal released.
–
 
With the selector in mode 
 N and the brake 
pedal released: when you place the gear 
selector in mode  D or M.
–
 
With the selector in mode 
 P and the brake 
pedal depressed: when you place the gear 
selector in mode  R, N, D or M.
–
 
With reverse gear engaged.
Special cases
The engine will restart automatically if the 
conditions for operation are met again and in the 
following case:
– 
Automatic gearbox in mode  N
, vehicle speed 
exceeds 0.6 mph (1 km/h).
In this case, this indicator lamp flashes for 
a few seconds, then goes off.
Malfunctions
In the event of a fault with the system, this 
warning lamp flashes for a few moments 
on the instrument panel, then remains on, 
accompanied by the display of a message.
Have it checked by a CITROËN dealer or a 
qualified workshop.
The vehicle stalls in STOP mode
All of the instrument panel warning lamps come 
on if there is a fault.
►
 
Switch off the ignition then start the engine 
again with the " ST
ART/STOP" button.
12 V battery
The Stop & Start system requires a 
12 V battery of specific technology and 
specification.
All work must be carried out only by a 
CITROËN dealer or a qualified workshop
Tyre under-inflation  detection
This system alerts the driver when one or more 
tyres have a drop in pressure.
The alert is raised when the vehicle is moving, 
not when stationary.
It compares the information given by the wheel 
speed sensors with  reference values, which 
must be reinitialised every time the tyre 
pressures are adjusted or a wheel changed.
It takes the last values 
  
stored during 
the
  reinitialisation   request into account. It is 
therefore essential that the tyre pressure is 
correct during the operation. This operation is 
the driver’s responsibility.
The tyre under-inflation detection cannot,  in any circumstances, replace the need 
for vigilance on the part of the driver.
This system does not avoid the need to 
regularly check the tyre pressures (including 
the spare wheel), especially before a long 
journey.
Driving with under-inflated tyres, particularly 
in adverse conditions (heavy load, high 
speed, long journey):
–
 
worsens road-holding.
–
 
lengthens braking distances.
–
 
causes premature wear of the tyres.
–
 
increases energy consumption.
The inflation pressures defined for the  vehicle can be found on the tyre pressure 
label.
For more information on the  Identification 
markings, refer to the corresponding section.
Checking tyre pressures
This check should be done monthly 
when the tyres are "cold" (vehicle stopped for 
1 hour or after a journey of less than 6 miles 
(10
 
km) at moderate speeds).
Otherwise, add 0.3 bar to the pressures 
shown on the label.   
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6Snow chains
The system does not have to be 
reinitialised after fitting or removing snow 
chains.
Under-inflation alert
This is signalled by the fixed illumination  of this warning lamp, accompanied by an 
audible signal and, depending on equipment, the 
display of a message.
►
 
Reduce speed immediately
 , avoid excessive 
steering movements and avoid sudden braking.
►
 
Stop the vehicle as soon as it is safe to do 
so.
The loss of pressure detected may not  always cause visible deformation of the 
tyre.
Do not rely on just a visual check.
►
 
Using a compressor
 , such as the one in 
the temporary puncture repair kit, check the 
pressures of all four tyres when cold.
►
 
If it is not possible to carry out this check 
immediately
, drive carefully at reduced speed.
►
 
In the event of a puncture, use the 
temporary puncture repair kit or the spare wheel 
(depending on equipment).
Driving too slowly may not ensure 
optimum monitoring.
The alert is not immediately triggered in the 
event of a sudden loss of pressure or tyre 
blow-out. This is because analysis of the 
values read by the wheel's speed sensors 
can take several minutes.
The alert may be delayed at speeds below 
25 mph (40 km/h), or when adopting a sporty 
driving mode.
The alert is kept active until the system is  reinitialised.
Reinitialisation
► The system must be reinitialised after any 
adjustment to the pressure of one or more tyres, 
and after changing one or more wheels.
Before reinitialising the system, make 
sure that the pressures of the four tyres 
are correct for the conditions of use of the 
vehicle and conform to the values written on 
the tyre pressure label.
Check the pressures of the four tyres before 
performing the reinitialisation.
The system does not advise if a pressure is 
incorrect at the time of reinitialisation.
With the vehicle stationary, the system 
can be reinitialised in the 
Settings>Vehicle touch screen application.
►
 
Then select 
 Safety>Under-inflation 
reinitialisation .
►
 
Press 
 YES to confirm.
The
 
reinitialisation   is confirmed by the display of 
a message and an audible signal.
Malfunction
In the event of a malfunction, 
these warning lamps light up on 
the instrument panel.
A message appears, accompanied by an audible 
signal.
In this case, the tyre under-inflation monitoring 
function is no longer performed.
Have it checked by a CITROËN dealer or a 
qualified workshop.
"Space-saver" type spare wheel
The use of this type of spare wheel may 
suspend tyre pressure monitoring.
In this case, the malfunction warning lamp 
comes on and disappears once the wheel 
has been replaced by one of uniform size (the 
same as the others), the pressure readjusted 
and the
  reinitialisation   carried out.
Driving and manoeuvring 
aids - General 
recommendations
Driving and manoeuvring aids cannot, in 
any circumstances, replace the need for 
vigilance on the part of the driver.
The driver must comply with the Highway 
Code, must remain in control of the vehicle in 
all circumstances and must be able to retake 
control of it at all times. The driver must adapt    
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the speed to climatic conditions, traffic and 
the state of the road.
It is the driver's responsibility to constantly 
monitor traffic conditions, assess the distance 
and relative speed of other vehicles, and 
anticipate their manoeuvres before using the 
direction indicator and changing lanes.
These systems do not make it possible to 
exceed the laws of physics.
Driving aids
You should hold the steering wheel with 
both hands, always use the door and interior 
mirrors, always leave your feet close to the 
pedals and take a break every 2 hours.
Manoeuvring aids
The driver must always check the 
surroundings of the vehicle before and during 
the whole manoeuvre, in particular using the 
mirrors.
Radar(s)
The operation of the radar(s), along with 
any associated functions, may be affected 
by the accumulation of dirt (e.g.
  mud, ice), 
in poor weather conditions (e.g.
  heavy rain, 
snow), or if the bumpers are damaged.
If the front bumper is to be repainted, contact 
a CITROËN dealer or a qualified workshop; 
certain types of paint could interfere with the 
operation of the radar(s).
 
 
Driving aids camera
This camera and its associated functions 
may be impaired or not work if the windscreen 
area in front of the camera is dirty, misty, 
frosty, covered with snow, damaged or 
masked by a sticker.
In humid and cold weather, demist the 
windscreen regularly.
Poor visibility (inadequate street lighting, 
heavy rain, thick fog, snowfall), dazzle 
(headlamps of an oncoming vehicle, low sun, 
reflections on a damp road, leaving a tunnel, 
alternating shade and light) can also impair 
detection performance.
In the event of a windscreen replacement, 
contact a CITROËN dealer or a qualified 
workshop to recalibrate the camera; 
otherwise, the operation of the associated 
driving aids may be disrupted.
Other cameras
The images from the camera(s) 
displayed on the touch screen or on the 
instrument panel may be distorted by the 
terrain.
In the presence of areas in shade, or in 
conditions of bright sunlight or inadequate 
lighting, the image may be darkened and with 
lower contrast.
Obstacles may appear further away than they 
actually are.
Sensors
The operation of the sensors, as well as 
any associated functions, may be disrupted 
by noise pollution such as that emitted by 
noisy vehicles and machinery (e.g. lorries, 
pneumatic drills), by the accumulation of 
snow or dead leaves on the road or in the 
event of damaged bumpers and mirrors.
When reverse gear is engaged, an audible 
signal (long beep) indicates that the sensors 
may be dirty.
A front or rear impact to the vehicle can 
upset the sensors’ settings, which is not 
always detected by the system: distance 
measurements may be distorted.
The sensors do not systematically detect 
obstacles that are too low (pavements, studs) 
or too thin (trees, posts, wire fences).
Certain obstacles located in the sensors’ blind 
spots may not be detected or may no longer 
be detected during the manoeuvre.
Certain materials (fabrics) absorb sound 
waves: pedestrians may not be detected.   
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6Maintenance
Clean the bumpers and door mirrors and 
the field of vision of the cameras regularly.
When washing your vehicle at high pressure, 
direct the spray from at least 30
  cm away 
from the radar, sensors and cameras.
Mats / Pedals covers
The use of mats or pedals covers not 
approved by CITROËN may interfere with 
the operation of the speed limiter or cruise 
control.
T
o avoid any risk of jamming the pedals:
–
 
Ensure that the mat is secured correctly
 .
–
 
Never fit one mat on top of another
 .
Units of speed
Ensure that the units of speed displayed 
in the instrument panel (mph or km/h) are 
those for the country you are driving in.
If this is not the case, when the vehicle is 
stationary, set the display to the required 
units of speed so that it complies with what is 
authorised locally.
In case of doubt, contact a CITROËN dealer 
or a qualified workshop.
Steering wheel with 
hands-on detection
(with Highway Driver Assist 2.0)
For more information, refer to the 
General recommendations on the use 
of driving and manoeuvring aids .
The steering wheel is equipped with a hands-on 
detection system to avoid distraction on the part 
of the driver.
It is prohibited to cover or attach anything to the 
steering wheel.
The driver must always check the  surroundings of the vehicle and 
supervise the whole manoeuvre.
Any use of a system built into
  Highway Driver 
Assist 2.0
  must remain under the driver’s 
vigilance.
The system also detects the presence of 
hands when using the Lane Positioning assist 
system with Highway Driver Assist.
The system may suffer interference or  not work correctly if:
–
 
the steering wheel is covered by some 
protection.
–
 
the driver wears thick gloves (e.g.
   ski 
gloves).
In the event of improper detection of hands on 
the steering wheel, Highway Driver Assist 2.0 
is not activated or is deactivated after a few 
seconds.
Installation of mechanical anti-theft 
devices on the steering wheel is 
prohibited - risk of damage!
Shortcuts for driving aids
Driving aids can be accessed directly to quickly 
activate/deactivate them.
By default, driving aids are already stored in the 
system (e.g. Stop & Start,
 
Active lane departure 
warning system).
Other driving aids can be added or deleted from 
the page.
It is configured in the ADAS>Functions 
touch screen application.
► Press the button corresponding to the 
driving assistance concerned: 
•
 
Full symbol: the function is added to the 
shortcuts.
•
 
Empty symbol: the function is deleted from 
the shortcuts.
►
 
Check the modification in the  Shortcuts
 tab.   
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► Press this button; the content is identical to 
that of the  Shortcuts tab.
Road signs recognition
For more information, refer to the 
General recommendations on the use 
of driving and manoeuvring aids .
 
 
This system displays the maximum speed 
authorised locally on the instrument panel, using:
–
 
Speed limit signs detected by the camera.
–
 
Speed limit information from the navigation 
system’
s mapping. –
 
Signs indicating a shared traffic zone detected 
by the camera.
Sign detected Suggested speed  (calculated)
Entry into a shared  traffic zoneExample:
 
 
Without MyCitroën 
Drive Plus
10 mph or 20
  km/h 
(depending on 
the units on the 
instrument panel) With MyCitroën  Drive Plus
Display of the speed 
in force in the country  you are driving in.
–
 
Some supplementary traffic signs detected by 
the camera.
Supplementary 
traffic sign detected Display of 
the   speed 
associated with 
the supplementary  traffic sign
Speed limit when  raining
Examples:
 
 
If the wiper control  stalk is in the 
"intermittent wipe" 
or "automatic wipe"  position (in order 
to activate the rain  sensor):
68 mph (110
  km/h) 
(for example)
Speed limit when  towing
 
 
If an approved towing device is fixed to the  vehicle:
56 mph (90
  km/h) 
(for example)
Speed limit 
applicable over a  certain distance Example:
 
 
43 mph (70 km/h) 
(for example)   
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6Deactivation/Activation
By default, the system is automatically activated 
at every engine start.
It is configured in the ADAS touch screen 
application.
Deactivation of the system is signalled by 
the illumination of this warning lamp, 
accompanied by the display of a message.
Operating conditions and 
limits
Vehicle moving forward without trailer.
Brake system operational.
ASR / ESP system activated.
Seat belts fastened for all passengers.
Stabilised speed on roads with no or low 
curvature.
This warning lamp lights up on the  instrument panel without any additional 
message, to indicate that the “automatic braking 
system” is not available. This is a normal 
behavior indicating that a condition is not fulfilled 
and which does not request the support of a 
workshop. 
In any situations with ignition on where automatic 
braking presents a risk, deactivating the 
system via ADAS touch screen application is 
recommended, for instance:
–
 
T
owing a trailer (particularly a trailer without its 
own braking system).
–
 
Carrying long objects on roof bars.
–
 
Driving with snow chains.
– Using an automatic car wash.
–  Performing any maintenance (e.g. changing a 
wheel, working underhood).
–
 
Placing the vehicle on a rolling bench in a 
workshop.
–
 
T
 owing the vehicle.
–
 
Following a front bumper deformation (version 
with radar).
–
 
Following 
 an impact to the windscreen close to 
the detection camera.
The system is automatically deactivated  if:
–
 
A
 spare wheel with a too small diameter is 
detected.
–
 
A
 fault with the brake pedal switch or with 
the right or left brake lamp is detected.
–
 
A
 fault in the sensors, in the electronic or in 
the brake system is detected.
–
 
A
 trailer is detected by the equipped vehicle 
hitch (with an electrical connection plug).
The system diagnoses permanently its  capability and may inhibit itself without 
specific driver indication, if the system is 
outside of the regular operating conditions. 
Examples: sensor initialization, board voltage 
out of regular range, activation of stability 
system… 
Therefore the system may not be available 
just after starting the vehicle. 
It can be dangerous to drive if the brake 
lamps are not in perfect working order.
The driver must not load his vehicle  excessively (respect of MTAC values, 
MTRA values and loading height on roof 
bars).
Following an impact (e.g. a collision), the 
system is automatically deactivated.
Have it checked by a CITROËN dealer or a 
qualified workshop.
Collision Risk Alert
This function warns the driver if there is a risk 
of collision with the preceding vehicle, or with a 
pedestrian or cyclist.
Modifying the alert trigger threshold
The trigger threshold determines the sensitivity 
with which the function warns of the risk of 
collision.
It is configured in the ADAS touch screen 
application.
►
 
Select one of the 3 preset thresholds: “ Far
”, 
“Medium” or “Near”.
The selected threshold is memorised when the 
ignition is switched off.
Operation
Depending on the collision risk detected by the 
system and the alert trigger threshold chosen    
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6Operation
The system operates subject to the following 
conditions:
– 
The vehicle's speed does not exceed 50 
mph (80 km/h) when a pedestrian or a cyclist is 
detected.
–
 
The vehicle's speed does not exceed 50 mph 
(80 km/h) when a stationary vehicle is detected.
–
 
The vehicle's speed is between 6 mph and 
53 mph (10
  km/h and 85 km/h) (versions with 
camera only) or 87 mph (140 km/h) (versions 
with camera and radar) when a moving vehicle 
is detected.
This warning lamp flashes (for  approximately 10 seconds) as soon as 
the function applies the vehicle’s brakes. During 
the flashing time, the function is not available.
In the event of automatic emergency braking, 
keep the brake pedal depressed, also after a 
complete stop is reached, to prevent the vehicle 
from rolling away.
The driver can override the "automatic  emergency braking" at any time by firmly 
turning the steering wheel and/or firmly 
depressing the accelerator pedal.
The brake pedal may feel hard and  vibrate slightly while the function is 
operating.
If the vehicle comes to a complete stop, 
automatic braking is maintained for 1 to 2 
seconds.
Turning scenarios
Crossing road with another vehicle 
 
The system may operate when the vehicle is 
turning and detects another vehicle, on the 
adjacent lane, approaching from the opposite 
direction if:
–
 
The corresponding direction indicator is 
activated.
–
 
Then the vehicle is about to cross the path of 
another vehicle.
–
 
The vehicle speed is between 3 and 12
   mph 
(5 and 20
  km/h).
–
 
A
  collision on the side of the other vehicle is 
probable.
Crossing road with a pedestrian 
 
The system may operate when the vehicle 
is turning left or right and detects a crossing 
pedestrian if: 
–
 
The pedestrian is crossing in front of the 
vehicle.
–
 
The pedestrian can clearly be detected by the 
sensors.
–
 
The scenery is detectable by the sensors (e.g. 
brightness, contrast vs background).
–
 
The vehicle speed is between 3 and 15
   mph 
(5 and 25
  km/h).
Malfunction
This warning lamp lights up on the instrument panel with the message 
"Sensor blind" in certain cases. With the variant 
"camera only", the system is deactivated. With 
the variant "camera and radar", the system may 
continue to operate in a degraded mode. This 
may be caused by a reduced visibility (rain, fog, 
snow, blending by low sun…) or by a real sensor 
blockage. In this case, stop the vehicle and verify    
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Driving
 
A warning lamp appears in the door mirror on the 
side in question:
– 
fixed
 , immediately when another vehicle is in 
the blind spot or is approaching in an adjacent 
lane.
–
 
flashing , after about 1 second when the 
direction indicator is used.
Activation/Deactivation
It is configured in the ADAS touch screen 
application.
When starting the vehicle, the
  warning   lamp 
comes on in each mirror to indicate that the 
system is activated.
The status of the system is memorised when the 
ignition is switched off.
The system is automatically deactivated  when towing with a towing device 
approved by CITROËN.
Operating conditions
– All vehicles are moving in the same direction 
and in adjacent lanes.
–
 
When overtaking a vehicle, the speed 
difference is less than 9
  mph (15   km/h).
– Traffic is flowing normally.
– When overtaking a vehicle over a certain 
period of time, the vehicle being overtaken 
remains in the blind spot.
Operating limits
No alert is triggered in the following conditions:
–  presence of stationary objects (e.g.   parked 
vehicles, safety rails, lampposts, signs).
–
 
vehicles travelling in the opposite direction.
–
 
if the rear bumper is damaged.
It is possible that warnings are not given, 
are given too late or seem unjustified. 
This system does not replace the need for 
vigilance on the part of the driver. Always 
check in the mirrors and look over your 
shoulders before changing lanes to avoid an 
accident. 
If the rear bumper is to be repainted, contact 
a dealer or a qualified workshop; certain types 
of paint could interfere with the operation of 
the radars.
Malfunction
If the event of a malfunction, this warning 
lamp comes on in the instrument panel, 
accompanied by the display of a message.
Have it checked by a CITROËN dealer or a 
qualified workshop.
The system may be temporarily disturbed  by certain weather conditions (e.g.   heavy 
rain, hail or extreme temperature changes).
In particular, driving on a wet road or going 
from a dry to a wet area can cause false 
alerts (e.g.
  presence of a cloud of water 
droplets in the blind spot interpreted as a 
vehicle).
In bad or wintry weather, ensure that the 
sensors are not covered by mud, ice or snow.
Take care not to cover the warning zone in 
the door mirrors, or the detection zones on 
the rear bumper with adhesive labels or other 
objects; they may hamper correct operation of 
the system.
Parking sensors
For more information, refer to the 
General recommendations on the use 
of driving and manoeuvring aids .
 
    
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6This system detects and signals the proximity of 
obstacles (e.g.  pedestrian, vehicle, tree, barrier) 
using sensors located in the bumper.
Rear parking sensors
► Engage reverse gear to start  the system 
(confirmed by an audible signal).
The system is switched off when reverse gear is 
disengaged.
Audible assistance 
 
The system signals the presence of obstacles 
which are both within the sensors’ detection zone 
and in the vehicle path defined by the direction of 
the steering wheel.
 
 
Depending on version, in the example shown, 
only the obstacles present in the shaded area 
will be signalled by the 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 about thirty 
centimetres, the audible signal becomes 
continuous.
The sound emitted by the speaker (right or 
left) indicates the side on which the obstacle is 
located.
Adjusting the audible signalPressing this button in the touch 
screen opens the window for 
adjusting the volume of the audible signal.
Visual assistance 
 
This supplements the audible signal, without 
taking account of the vehicle's trajectory, by 
displaying bars on the screen that represent the 
distance between the obstacle and the vehicle 
(white: more distant, orange: close, red: very 
close).
When the obstacle is very close, the "Danger" 
symbol is displayed on the screen.
Front parking sensors
Supplementing the rear parking sensors, the 
front parking sensors are triggered when an 
obstacle is detected in front and the speed of the 
vehicle is below 6 mph (10
  km/h).
Front parking sensor operation is suspended if 
the vehicle stops for more than three seconds in 
forward gear, if an obstacle is no longer detected 
or the vehicle speed exceeds 6
  mph (10   km/h).
The sound emitted by the speaker (front or rear) locates the obstacle relative to 
the vehicle, whether in front of or behind it on 
its path.
Deactivation/Activation
It is configured in the ADAS touch screen 
application.
If the function is deactivated, this indicator 
lamp lights up on the instrument panel.
The system status is saved when the ignition is 
switched off.