MERCEDES-BENZ C-CLASS CABRIOLET 2021 Owners Manual

#
Push handle 1ofthe bonn etcatch up wards
and lift the bonn etuntil it opens automati‐
call y.
Closing the bonnet #
Lowe rth e bonn etto a height of around
20 cm and then allow it tofall, applying a lit‐
tle forc e as you let it go. #
Ifth e bonn etcan still be lif ted slightl y,open
th e bonn etagain and close it with a little
more forc e until it engages cor rectly. Engine oil
Che
cking the engine oil le vel using the oil
dip stick &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. Re
quirements:
R The engine has an oil dipstic k.If not, the
engine oil le vel can be checked only with the
on-board computer (/ page 359) . Depending on
the engine, the oil dipstick may be
ins talled in the engine compartment in dif fere nt
locations.
The waiting time before checking the oil le vel
when the engine is at normal operating temp era‐
ture is five minutes. #
Park theve hicle on a le vel sur face. #
Pull oil dipstick 1out and wipe off. 358
Maintenance and care

#
Slowly slide oil dipstick 1into the guide
tube tothestop, and pull it out again af ter
about thre e seconds.
R Oil le vel is cor rect: oil le vel is between 2
and 3.
R Oil le velto o low: oil le vel is at 3or
belo w.
R Oil le velto o high: oil le vel is abo ve2 . #
Ifth e oil le vel is too lo w,top up with 1 litre of
engine oil. #
Ifth e oil le vel is too high, drain off excess
engine oil. Consult a qualified specialist
wo rkshop.
Checking the engine oil le vel using the on-
board compu ter
Re quirements:
R The engine has an oil le vel sensor. If not, the
engine oil le vel can be checked only with the
oil dipstick (/ page 358).
R The engine has been warmed up.
R The vehicle is par ked on a le vel sur face.
R The engine is running at idle speed. R
The bonnet is closed.
The engine oil le vel is de term ined during driving.
De term ining the engine oil le vel can take up to
30 minutes with a normal driving style and even
longer with an active driving style.
On-board computer: 4 Service 5
Engine oil level
One of thefo llowing messages will appear on
th e multifunction display:
R Engine oil level Measuring now : measure‐
ment of the oil le vel is not yet possible. #
Repeat there qu est af ter a maximum of
30 minutes' driving.
R Engine oil level OK andthe bar display for
indicating the oil le vel on the multifunction
display is green and is between "min" and
"max": the oil le vel is cor rect.
R Engine oil level Add 1.0 l andthe bar display
fo r indicating the oil le vel on the multifunc‐
tion display is orange and is below "min": #
Add 1 l of engine oil. R
Reduce engine oil level andthe bar display
fo r indicating the oil le vel on the multifunc‐
tion display is orange and is abo ve"max": #
Drain off any excess engine oil that has been
added. Todo so, consult a qualified specialist
wo rkshop.
R For engine oil level turn on ignition #
Switch on the ignition tocheck the engine oil
le ve l.
R Engine oil level System inoperative : The oil
le ve l sensor is defective or not connec ted. #
Consult a qualified specialist workshop.
R Engine oil level System currently unavail. #
Close the bonn et.
To pping up engine oil &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. Maintenance and care
359

#
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. &
WARNING Risk offire and injury from
engine oil
If engine oil comes into con tact wi thhot
component parts in the engine compart‐
ment, it may ignite. #
Make sure that no engine oil is spilled
next tothefiller opening. #
Allow the engine tocool off and thor‐
oughly clean the engine oil from compo‐
nent parts before starting theve hicle. *
NO
TEEngine dama gecaused byan
incor rect oil filter, incor rect oil or addi‐
tives #
Do not use engine oils or oil filters
which do not cor respond tothe specifi‐
cations explicitly prescribed forthe
service inter vals. #
Follow the instructions on the service
inter val display forch anging the engine
oil and obser vethe prescribed change
inter vals. #
Do not use additives. *
NO
TEDama gecaused bytopping up too
much engine oil To
o much engine oil can damage the engine
or the catalytic con verter. #
Have excess engine oil remo ved at a
qu alified specialist workshop. %
Depending on driving style, theve hicle con‐
sumes up to0.8 litr e of oil pe r10 00 km. The
oil consum ption may be higher than this
when theve hicle is new or if you frequently
drive at high engine speeds. #
Turn cap 1anti-clockwise and remo veit. #
Top up the engine oil. #
Replace cap 1and turn it clockwise until it
engages. #
Check the oil le vel again (/ page 358). 360
Maintenance and care

Checking
the coolant le vel &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. &
WARNING Risk of scalding from hot
coolant
If yo u open the cap, you could be scalded. #
Let the mo tor cool down before opening
th e cap. #
When opening the cap, wear pr otective
gl ove s and saf etygl asses. #
Open the cap slowly torelease pres‐
sure. #
Park theve hicle on a le vel sur face. #
Check the coolant temp erature display in the
instrument clus ter.
The coolant temp erature must be below
70°C. #
Slowly turn cap 1anti-clockwise torelease
ove rpressure. #
Continue turning cap 1anti-clockwise and
re mo veit.
The coolant le vel is cor rect in thefo llowing
cases:
R Ifth e engine is cold, the coolant is up to
mar ker bar 2.
R Ifth e engine is warm,th e coolant is up to
1. 5 cm overth e mar ker bar 2. #
If necessar y,top up with coolant that has
been appr ovedfo r Mercedes-Benz.
% Further information on coolant
(/ page 424) To
pping up the windsc reen washer sy stem &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. Maintenance and care
361

#
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. &
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. #
Remo vecap 1bytheta b. #
Top up thewa sher fluid.
% Further information about the windscreen
wa sher fluid (/ page 425) Ke
eping the air-water duct free #
Keep the area between the bonn etand the
windscreen free of deposits, e.g. ice, sn ow
and lea ves. Cleaning and care
Information on
washing theve hicle in a car
wa sh &
WARNING Risk of an accident due to
re duced braking po wer af terwa shing the
ve hicle
Braking ef ficiency is reduced af terwa shing
th eve hicle. #
Afterth eve hicle has been washed,
brake carefully while paying attention to
th e traf fic conditions until braking
po we r has been fully restored. 362
Maintenance and care

*
NO
TEDama gefrom auto matic braking If one of
thefo llowing functions is switched
on, theve hicle brakes automatically in cer‐
ta in situations:
R Active Brake Assi st
R Active Dis tance Assi stDISTRONIC
R HOLD function
R Active Parking Assist
To avo id damage totheve hicle, deactivate
th ese sy stems in thefo llowing or similar sit‐
uations: #
during towing #
in a car wash *
NO
TEDama gedue tounsuitable car
wa sh #
Before driving into a car wash make
sure that the car wash is suitable for
th eve hicle dimensions. #
Ensure there is suf ficient ground clear‐
ance between the underbody and the
guide rails of the car wash. #
Ensure that the clearance width of the
car wash, in particular the width of the
guide rails, is suf ficient. To
avo id damage to yourvehicle when using a
car wash, ensure thefo llowing beforehand:
R toavoid possible water ingress in theve hicle,
it is preferable touse car washes which allow
th e high-pressure pre-cleaning tobe deacti‐
va ted (specification forth e cabriolet pro‐
gram).
R avoid any hot-wax treatment.
R make sure that the wind deflector on the
windscreen has been retracted.
R Active Dis tance Assi stDISTRONIC is deacti‐
va ted.
R the HOLD function is switched off.
R the 360° Camera or there ve rsing camera is
switched off. R
the side windo wsand soft top are closed
comple tely.
R the blo werfo rth eve ntilation and heating is
switched off.
R the windscreen wiper switch is in position
g.
R theke y is at a minimum dis tance of 3 m
aw ay from theve hicle. Otherwise the boot lid
could open unintentionall y.
R for car washes with a con veyo r sy stem:
- neutral iis engaged.
- ifyo uwo uld like tolea vetheve hicle while
it is being washed, make sure theke y is
located in theve hicle. The park position
j isotherwise automatically engaged.
% If, af terth e car wash, youre mo vethewax
from the windscreen and wiper rubbers, this
will pr event smearing and reduce wiper
noise. Maintenance and care
363

Information on using a high-p
ressure cleaner &
WARNING Risk of an accident when
using high-pressure cleane rswith round-
spray nozzles
The wate r jet can cause extern ally invisible
damage.
Components damaged in this wa y may unex‐
pec tedly fail. #
Do not use a high-pressure cleaner with
round-spr aynozzles. #
Have damaged tyres or chassis parts
re placed immediatel y.To
avo id damage to yourvehicle, obser vethefo l‐
lowing when using a high-pressure cleaner:
R The key is at a minimum distance of 3 m
aw ay from theve hicle. Otherwise the boot lid
could open unintentionall y.
R Maintain a dis tance of at least 30 cm tothe
ve hicle.
R Vehicles with deco rative foil: Parts of your
ve hicle are co vered with a decorative foil. Maintain a dis
tance of at least 70 cm
between thefo il-c ove red parts of theve hicle
and the nozzle of the high-pressure cleaner.
Mo vethe high-pressure cleaner nozzle
around whilst cleaning. The waterte mp era‐
ture of the high-pressure cleaner must not
exc eed 60°C.
R Obser vethe information on the cor rect dis‐
ta nce in the equipment manufacturer's oper‐
ating instructions.
R Do not direct the nozzle of the high-pressure
cleaner directly at sensitive parts, such as
tyres, soft top, wind deflector net, gaps, elec‐
trical components, batteries, light sources
and ventilation slits. Wa
shing theve hicle byhand *
NO
TEEngine dama gedue towa ter
ing ress #
Take care not topoint thewate r jet
directly towa rdsth e air inlet grille below
th e bonn et. obser
vethe legal requ irements, e.g. in a number
of countries, washing byhand is only permitted
in specially designated wash ba ys. #
Use a mild cleaning agent, e.g. car shampoo. #
Washtheve hicle with luk ewarmwate r using
a soft car sponge. When doing so, do not
ex pose theve hicle todirect sunlight. #
Carefully hose theve hicle off with water and
dry using a chamois.
% Obse rveth e no tes on the care of car parts
(/ page 368). Note
s on paint work/matt finish paint work
care Obse
rveth e no tes on cleaning and care toavo id
damaging the paintwor k.
Pa int
R Insect remains: soak with insect remo ver and
ri nse off the treated areas af terw ards.
R Bird droppings: soak with water and rinse off
af te rw ards. 364
Maintenance and care

R
Tree resin, oils, fuels and greases: remo veby
ru bbing gently wi tha clo thsoaked in petro‐
leum ether or lighter fluid.
R Coolant and brake fluid: remo vewith a damp
clo thand clean water.
R Tarst ains: use tarre mo ver.
R Wax: use silicone remo ver.
R Do not attach sticke rs,fi lms or similar mate‐
ri als.
R Remo vedirt immediately, where possible.
Matt finish
R Only use care products appr ovedfor
Mercedes-Benz.
R Do not polish theve hicle and light-alloy
wheels.
R Only use car washes that cor respond tothe
latest engineering standards.
R Do not use car wash programmes with a final
hot wax treatment.
R Do not use paint cleane rs, buf fing or polish‐
ing products, gloss preser vers, e.g. wax. R
Alw ays ha vepaintwork repairs car ried out at
a qu alified specialist workshop. Note
s on cleaning decorative foils Obser
vethe no tes on matt finish care in the
ch ap ter "No tes on paintwork/matt finish paint‐
wo rkcare" (/ page 364). They also apply to
matt decorative foils.
Obser vethe no tes on cleaning decorative foils to
avo idvehicle damage.
Cleaning R For cleaning, use plenty of water and a mild
cleaning agent without additives or abrasive
subs tances, e.g. a car sha mpoo appr ovedfor
Mercedes-Benz.
R Remo vedirt immediatel y,where possible,
whilst avoiding rubbing too hard. There is
ot herwise a risk of damaging the decorative
fo il ir reparably.
R Ifth ere is dirt on thefinish or if the decora‐
tive foil is dull: use thePa int Cleaner recom‐
mended and appr ovedfo r Mercedes-Benz. R
Insect remains: soak with insect remo ver and
ri nse off the treated areas af terw ards.
R Bird droppings: soak with water and rinse off
af te rw ards.
R Topreve ntwate rst ains, dry a foil-wrapped
ve hicle with a soft, absorbent clo thafter
eve rycar wash.
Av oiding dama getothe decorative foil
R The service life and colouring of decorative
fo ils are impaired by:
- sunlight
- temp erature, e.g. hot air blo wer
- weather conditions
- stone chippings and dirt
- chemical cleaning agents
- oily products
R Do not use polish on matt decorative foil.
Po lishing will ha vethe ef fect of shining the
fo il-wrapped sur face.
R Do not treat matt or stru ctured deco rative
fo ils with wax.Pe rm anent stains may occur. Main
tenance and care 365

Scratches, cor
rosive deposits, areas af fected by
cor rosion and damage caused byincor rect care
cannot al ways be comple tely repaired. In such
cases, visit a qualified specialist workshop.
Yo u can obtain more information on care and
cleaning products from the manufacturer.
In the case of foil-wrapped sur faces, optical dif‐
fe re nces may occur between the sur faces that
we renot pr otected bya decorative foil af ter
re moving a decorative foil.
% Have wo rkor repairs todecorative foils car‐
ri ed out at a qualified specialist workshop,
e.g. in a Mercedes-Benz Service Centre. Note
s on cleaning and care of the soft top Obser
vethefo llowing no tes in order topreve nt
dama getothe soft top.
Light dirt R Clean the soft top when dr y.
R Rinse with clean water. Norm
alto heavy dirt
R Clean the soft top with a brush and clean
wate r.
R Clean stains and other heavy dirt with a
brush and soft-top cleaning agents recom‐
mended and appr ovedfo r Mercedes-Benz.
R Brush from front toback in the direction of
th efa bric.
Av oiding soft- top damage
R Never use petrol, thinners, tar or stain
re mo ver or other or ganic sol vents.
R Remo vebird droppings immediatel y,as they
are cor rosive and can therefore cause the
soft-top fabric toleak.
R Never use a high-p ressure cleaner.
R Do not use sharp-edged equipment to
re mo veice and sno w.
Fr equent cleaning reduces the soft top's resist‐
ance todirt. Torestore the ef fect, clean the soft
to p with the soft-to p cleaning agents recommen‐
ded and appr oved for Mercedes-Benz.
Incor rect cleaning and care, as well as ageing,
can cause the soft-to p seams toleak. If this hap‐ pens, ha
vethe soft-to p seams sealed at a quali‐
fi ed specialist workshop, e.g. at your Mercedes-
Benz service centre.
% Place a suitable co verove rth e soft top if you
plan tolea vetheve hicle outside for a long
period of time. Cleaning AIRC
AP Cleaning
the wind deflector
* NO
TEDama getothe net due tousing a
high-pressure cleaner #
Never use a high-p ressure cleaner to
clean the net of the wind deflector. Re
quirements:
R The soft top is closed.
R The elect ric pa rking brake has been applied.
R The ignition is switched on. 366
Maintenance and care

#
Pull button 1.
The wind deflector between the windscreen
and the soft top will extend. #
Light dirt: clean wind de flector net 1with
a soft brush or a damp clo th. #
Heavier dir t:clean net 1with care prod‐
ucts and cleaning agents recommended and
appr ovedfo r Mercedes-Benz. #
Rinse or spr aythe net with clean water.
Cleaning the draught stop
Re quirements:
R The soft top is open.
R The elect ric pa rking brake has been applied.
R The ignition is switched on. #
Pull button 1.
The AI RCAP draught stop will mo veupwards. Main
tenance and care 367