2021 MERCEDES-BENZ C-CLASS CABRIOLET sensor

minutes af
ter cleaning before parking it. The
brake disks and brakepads warm up and dry
out.
Wi ndo ws
R Clean the windo wsinside and outside with a
damp clo thand with a cleaning agent recom‐
mended for Mercedes-Benz.
R Do not use dry clo ths or abrasive or sol vent-
based cleaning agents toclean the inside of
windo ws.
% Remo veextern al fogging or dirt on the wind‐
screen in front of the multifunction camera.
Otherwise, driving sy stems and driving
saf ety sy stems may be impaired or not avail‐
able (/ page168).
Wi per blades
R Movethe wiper arms into there placement
position (/ page128).
R With th e wiper arms folded out, clean the
wiper blades with a damp clo th.
R Do not clean the wiper blades too of ten. Ex
terior lighting
R Clean the lenses with a wet sponge and mild
cleaning agent, e.g. car sha mpoo.
R Only use cleaning agents or cleaning clo ths
th at are suitable for plast ic lenses.
Sensors
R Clean the sensors in the front and rear
bumpers with a soft clo thand car shampoo
(/ page 168).
R When using a high-pressu recleane r,maintain
a minimum dis tance of 30 cm.
Re versing camera and 360° Camera
R Open the camera co ver with the multimedia
sy stem (/ page 209).
R Use clean water and a soft clo thtoclean the
came ralens.
R Do not use a high-pressure cleaner.
Ta ilpipes
R Clean with a cleaning agent recommended
fo r Mercedes-Benz, especial lyin the winter
and af terwa shing theve hicle.
R Do not use acidic cleaning agents. Tr
ailer hitch
R Obse rveth e no tes on care in the trailer hitch
manufacturer's operating instructions.
R Do not clean the ball neck with a high-pres‐
sure cleaner or solvent.
R Remo vetraces of rust on the ball, forex am‐
ple, with a wire brush.
R Remo vedirt with a lint-free clo th.
R After cleaning, lightly oil or grease the ball
head.
% Before using trailers with anti- torsional cou‐
pling, obser vethe manufacturer's operating
instructions. Note
s on care of the interior &
WARNING Risk of inju ryfrom pla stic
parts breaking off af terth e use of sol‐
ve nt-based care products
Ca reand cleaning products con taining sol‐
ve nts can cause su rfaces in the cockpit to
become porous. When the airbags are
deplo yed, plastic parts may break away. Maintenance and care
369

If
th e preceding tyre sizes are complemented by
th e+ symbol, the tyre pressure information
fo llowing sho wsalternative tyre pressures. Fuel
consum ption may then increase slightl y.
The load conditions "partially laden" and "fully
laden" are defined in theta ble for dif fere nt num‐
be rs of passengers and amounts of luggage. The
actual number of seats may dif fer from this. Ty
re pressure moni toring sy stem Fu
nction of the ty repressure moni toring sys‐
tem
The sy stem checks the tyre pressure and the
tyre temp erature of the tyres fitted totheve hicle
by means of a tyre pressu resensor.
The tyre pressure and the tyre temp erature
appear in the on-board computer (/ page 398).
If th ere is a subs tantial pressure loss or if the
tyre temp erature is excessive, you will be
wa rned with display messages (/ page475) or
th eh warning lamp in the instrument clus ter
( / page 498). The tyre pressure monitoring sy
stem is only an
aid. It is the driver's responsibility toset the tyre
pressure tothere commended cold tyre pressure
suitable forth e operating situation.
In most cases, the tyre pressure monitoring sys‐
te m will auto matically update the new refere nce
va lues af teryo u ha vechanged the tyre pressure.
Yo u can, ho wever,also update there fere nce val‐
ues byrestarting the tyre pressure monitoring
sy stem manually (/ page 399).
Sy stem limits
The sy stem may be impaired or may not function
particularly in thefo llowing situations:
R the tyre pressure has been set incor rectly
R sudden pressure loss caused byafo re ign
object penetrating the tyre, forex ample
R there is a malfunction caused byano ther
ra dio signal source
Checking the ty repressure with the tyre
pressure moni toring sy stem
Requ irements:
R The ignition is switched on. On-board computer:
4 Service 5
Tyres
One of thefo llowing displa ysappears:
R Cur rent tyre pressure and tyre temp erature
of the individual wheels: R
Tyre pressures will be displayed after a few
minutes of driving
R Tyre pressure monitor active: thete ach-in
process of the sy stem is not yet compl ete.
The tyre pressures are already being moni‐
to re d. #
Compare the tyre pressure with there com‐
mended tyre pressure forth e cur rent operat‐ 398
Wheels and tyres

R
Furthermore, the use of cer tain tyre types in
cer tain regions and areas of operation can
be highly beneficial.
R Only use tyres and wheels of the same type
(summer tyres, winter tyres, MOEx tended
tyres) and the same make.
R Only fit wheels of the same size on one axle
(left and right).
It is only permissible tofit a di fferent wheel
size in theeve nt of a flat tyre in order to
drive tothe specialist workshop.
R Do not make any modifications tothe brake
sy stem, the wheels or the tyres.
The use of shims or brake dust shields is not
permitted and may in validate theve hicle's
ge neral operating pe rmit.
R Vehicles with a tyre pressure monitoring
sy stem: allfitted wheels mu stbe equipped
with functioning sensors forth e tyre pres‐
sure monitoring sy stem.
R Attemp eratures below 7 °C use winter tyres
or all-season tyres mar kedi M+Sfor all
wheels. Wi
nter tyres pr ovide the best possible grip in
wintry road conditions.
R For M+S tyres, only use tyres with the same
tread.
R Obser vethe maximum permissible speed for
th e M+S tyres fitted.
If th e tyre's maximum speed is below that of
th eve hicle, this must be indicated byan
appropriate label in the driver's field of
vision.
R Run in new tyres at moderate speeds forthe
fi rs t10 0 km.
R Replace the tyres af ter six years at the latest,
re ga rdless of wear.
R When replacing with tyres that do not
fe ature run-flat characteristics: vehicles
with MOExtended tyres are not equipped
with a TIREFIT kit at thefa ctor y.Equip the
ve hicle with a TIREFIT kit af terre placing with
tyres that do not feature run-flat characteris‐
tics, e.g. winter tyres. %
You can permanently limit the maximum
ve hicle speed for driving with winter tyres
(/ page 179).
Fo r more information on wheels and tyres, con‐
ta ct a qualified specialist workshop.
Be sure toalso obse rveth efo llowing fur ther
re lated subjects:
R Notes on tyre pressure (/ page 396)
R Tyre pressure table (/ page 397)
R Notes on the emer gency spa rewheel
(/ page 410) Note
s on inter changing wheels &
WARNING Risk of inju rythro ugh dif fer‐
ent wheel sizes
Inter changing the front and rear wheels can
se verely impair the driving characteristics.
The disk brakes or wheel suspension compo‐
nents may also be damaged. Wheels and tyres
403

*
NO
TEOverheating at high outside tem‐
peratures If an inapp
ropriate coolant is used, the
engine cooling sy stem is not suf ficiently pro‐
te cted against overheating and cor rosion at
high outside temp eratures. #
Alw ays use coolant appr ovedby
Mercedes-Benz. #
Obser vethe instructions in the
Mercedes-Benz Specifications for Oper‐
ating Fluids 310.1. Ha
ve the coolant regularly replaced at a qualified
specialist workshop.
Proportion of antifreeze concentrate in the
engine cooling sy stem:
R a minimum of 50% (antifreeze pr otection
down toappr oximately -37°C)
R a maximum of 55% (antifreeze pr otection
down to-45°C) Note
s on windscreen washer fluid Obser
vethe no tes on operating fluids
(/ page 416). &
WARNING ‑ Risk of fire and injury due to
windscreen washer concentrate
Wi ndsc reen washer concentrate is highly
fl ammable. It could ignite if it comes into
con tact wi thhot engine component parts or
th eex haust sy stem. #
Make sure that no windsc reen washer
concentrate spills out next tothefiller
opening. *
NO
TEDama getotheex terior lighting
due tounsuitable windsc reen washer
fl uid Uns
uitable windsc reen washer fluids may
damage the plastic sur face of theex terior
lighting. #
Only use windscreen washer fluids
which are also suitable for use on plas‐ tic sur
faces, e.g. MB SummerFit or MB
Wi nterFit. *
NO
TEBlocked spr aynozzles caused by
mixing windscreen washer fluids #
Do not mix MB SummerFit and MB Win‐
te rFit with other windscreen washer flu‐
ids. Do not use distilled or de-ionised
water.Other‐
wise, thefill le vel sensor may be triggered er ro‐
neously.
Re commended windscreen washer fluid:
R abo vefreezing point: e.g. MB SummerFit
R below freezing point: e.g. MB WinterFit
Fo rth e cor rect mixing ratio, referto the informa‐
tion on the antif reeze conta iner.
Mix washer fluid with windsc reen washer fluid all
ye ar round. Te
ch nical da ta425

Lights
Display messages
Possible causes/consequences and M
MSolutions
: Left dipped beam (examp le) *T
he cor responding light source is defective. #
Drive on carefully. #
Consult a qualified specialist workshop immediatel y.
% LED light sources: the display message forth e cor responding light appears only when allthe light-emitting
diodes in the light are faulty.
: Malfunction See Owner's
Manual *T
heexterior lighting is malfunctioning. #
Consult a qualified specialist workshop.
* Ve hicles with a trailer hitch: a fuse may haveblown. #
Stop theve hicle in accordance with the tra ffic conditions. #
Check the fuses and replace them if necessary (/ page 391).
:
Automatic driving lights
inoperative *T
he light sensor for auto matic driving lights is malfunctioning. #
Consult a qualified specialist workshop. 438
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions #
Ifth e display message does not disappear, stop theve hicle in accordance with the tra ffic conditions and restart
th e engine. #
If necessar y,clean there ar bumper. If the bumper is especially dirty, the sensors in the bumper may be mal‐
functioning.
Blind Spot Assist inopera-
tive *B
lind Spot Assist is malfunctioning. #
Consult a qualified specialist workshop.
Blind Spot Assist not availa-
ble when towing a trailer
See Owner's Manual *W
hen you es tablish the electrical connection tothe trailer, Blind Spot Assist will be una vailable. #
Press the left-hand Touch Control and ackn owledge the display message.
Active Blind Spot Assist
currently unavailable See
Owner's Manual *A
ctive Blind Spot Assi stistemp orarily una vailable.
The sy stem limits ha vebeen reached (/ page195).
Once the cause of the problem is no longer present, the sy stem will be available again. #
Drive on.
or #
Ifth e display message does not disappear, stop theve hicle in accordance with the tra ffic conditions and restart
th e engine.
Active Blind Spot Assist
inoperative *A
ctive Blind Spot Assi stis malfunctioning. #
Consult a qualified specialist workshop. 462
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
É Vehicle rising *Y
our vehicle is adjusting tothe le velyo u ha veselected.
É Vehicle rising Please wait *T
hevehicle le vel is too lo w.The vehicle will be raised tothe selected vehicle le vel. #
Wait until the display message disappears before pulling away.
É Please reduce speed *Y
ou are driving toofast forth e selected vehicle le vel. #
Toadjust theve hicle le vel,yo u must not drive at speeds greaterth an 60 km/h. #
Toadjust theve hicle le vel during trailer operation, you must not drive at speeds greaterth an 30 km/h.
Parking Assist Manoeu-
vring assistance limited
See Owner's Manual *T
heParking Assist manoeuvring assis tant is temp orarily una vailable or only partially available. #
Clean all sensors of the parking and camera sy stem (/ page 368). #
Ifth e display message still appears, consult a qualified specialist workshop.
Parking Assist and
PARKTRONIC inoperative
See Owner's Manual *
Ve hicles with Active Parking Assis t:Ac tive Parking Assist and Parking Assist PARKTRONIC are malfunctioning.
Ve hicles without Active Parking Assis t:Pa rking Assist PARKTRONIC is malfunctioning. #
Stop theve hicle in accordance with the tra ffic conditions and restart the engine. 466
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
Active Brake Assist Func-
tions limited See Owner's
Manual *F
orvehicles with the Driving Assis tance Package, thefo llowing functions may be temp orarily una vailable or limited:
R Active Brake Assi stwith cross-traf fic function
R Evasi veSteering Assist
R PRE‑SAFE ®
PLUS
Ve hicles without the Driving Assistance Package: Active Brake Assi stistemp orarily una vailable or only partially
av ailable. #
Consult a qualified specialist workshop.
Radar sensors dirty See
Owner's Manual *T
heradar sensor sy stem is malfunctioning. Possible causes:
R Dirt on the sensors
R Heavy rain or snow
R Extended country driving wi thout other traf fic, e.g. in the desert
Driving sy stems and driving saf ety sy stems may be malfunctioning or temp orarily una vailable.
Once the cause of the problem is no longer present, the driving sy stems and driving saf ety sy stems will be available
again.
If th e display message does not disappear: #
Stop theve hicle in accordance with the tra ffic conditions. #
Clean all sensors (/ page 368). #
Restart the engine. Display messages and
warning/indicator lamps 471