2021 MERCEDES-BENZ C-CLASS CABRIOLET warning

fi
ed based on the actual operating conditions
and/or loads.
Examples of arduous operating conditions:
R regular city driving with frequent intermedi‐
ate stops
R mainly short-dis tance driving
R frequent operation in mountainous terrain or
on poor road sur faces
R when the engine is of ten le ftidling for long
periods
R operation in particula rly dusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequent ly. The
ty re s must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop. Battery disconnection periods
The ASS
YST PLUS service inter val display can
calculate the service due date only when the
battery is connec ted. #
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (/ page 354). Engine compartment
Ac
tive bonn et(pedestrian pr otection) Operation of
the active bonnet (pedestrian
pr otection)
In cer tain accident situations, the actuation of
th e active bonn etreduces therisk of injury to
pedestrians. The rear area of the bonn etis
ra ised byappr oximately 85 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonn etyourself (/ page 355).
Af terth e active bonn ethas been actuated,
pedestrian pr otection may be limited.
Ha ve the full functionality of the active bonn et
re stored in a qualified specialist workshop. Re
setting the active bonnet &
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. Maintenance and care
355

#
With your hand flat, push down active bonnet
1 inthe area around the hinges on bo th
sides (ar rows).
In doing so, the actuator is depressurised
and you may hear a hissing sound.
The engine bonnet must en gage in position. #
Ifth e active bonn etcan be raised slight lyat
th ere ar in the area of the hinges, repeat the
st ep until it engages cor rectl y. Opening and closing
the bonnet &
WARNING Risk of accident due todriv‐
ing with the bonn etunlo cked
The bonn etmay open and block your vie w. #
Neverre lease the bonn etwhen driving. #
Before every trip, ensure that the
engine bonn etis loc ked. &
WARNING Risk of accident and inju ry
when opening and closing the bonn et
The bonnet may suddenly drop into the end
position.
There is a risk of injury for an yone in the
engine bonn et's range of mo vement. #
Do not open or close the bonn etifth ere
is a person in the bonn et's range of
mo vement. &
WARNING Risk of bu rns when opening
th e bonn et
If yo u open the bonn etwhen the engine has
ove rheated or when there is a fire inthe
engine compartment, thefo llowing situations
may occur:
R You could come into contact with hot
ga ses.
R You could come into contact with other
hot, escaping operating fluids. #
Before opening the bonn et, allow the
engine tocool down. #
Intheeve nt of a fire inthe engine com‐
partment, keep the bonn etclosed and
call thefire service. &
WARNING Risk of inju rydue tomoving
parts
Components in the engine compartment may
continue running or start up sudden ly,even if
th e ignition is switched off.
Make sure of thefo llowing before per form ing
ta sks in the engine compartmen t: #
Switch the ignition off. #
Neverre ach into the danger zone sur‐
ro unding moving co mponents, e.g. the
ro tation area of thefa n. #
Remo vejewe llery and watches. #
Keep items of clo thing and hair away
from moving parts. 356
Maintenance and care

&
WARNING Risk of inju ryfrom touching
co mp onents under voltage
The ignition sy stem and the fuel injection
sy stem workunder high voltage. You could
re cei vean electric shoc k. #
Neverto uch co mponents of the ignition
sy stem or the fuel injection sy stem
when the ignition is switched on. The live components include
thefo llowing, for
ex ample:
R Ignition coils
R Spark plug connec tors
R Injectors &
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 inju ryfrom using the
windscreen wipers while the engine bon‐
net is open
When the engine bonn etis open, and the
windscreen wipers are set in motion, you can
be trapped bythe wiper linkage. #
Alw ays switch off the windscreen wip‐
ers and ignition before opening the
engine bonn et. Opening
the bonnet #
Torelease the bonn et, pull on handle 1. Maintenance and care
357

#
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