2021 MERCEDES-BENZ C-CLASS CABRIOLET bonnet

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

Display messages
Possible causes/consequences and M
MSolutions
Ù Steering malfunction
Increased physical effort
See Owner's Manual *T
he po werst eering assis tance is malfunctioning. &
WARNING Risk of an accident due toaltered steering characteristics
If th e po wer assi stance of thesteering fails partially or comple tely, you will need touse more forc eto steer. #
If safe steering is possible, drive on carefully. #
Visit or consult a qualified specialist workshop immediatel y. Ù
Steering malfunction Stop
immediately See Owner's
Manual *T
hesteering is malfunctioning. Steering capability is significant lyimpaired. &
WARNING Risk of accident if steering capability is impaired
If th esteering does not function as intended, theve hicle's operating saf ety is jeopardised. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions.
Do not continue driving under any circums tances. #
Consult a qualified specialist workshop. Active bonnet malfunction
See Owner's Manual
*T
he active bonnet (pedestrian pr otection) is malfunctioning or inoperative af ter having already been triggered. #
Consult a qualified specialist workshop.
C *A
t least one door is open. #
Close all doors. Displ
aymessa ges and warning/indicator lamps 443

Display messages
Possible causes/consequences and M
MSolutions
M *T
he bonnet is open. &
WARNING Risk of accident due todriving 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. #
Stop theve hicle immediately in accordance with the traf fic conditions. #
Close the bonn et.
N *T
he boot lid is open. &
DANG ER Risk of exhaust gas poisoning
Combustion engines emit poisonous exhaust gases such as carbon monoxide. Exhaust gases can enter the
ve hicle interior if the boot lid is open when the engine is running, especially if theve hicle is in motion. #
Alw ays switch off the engine before opening the boot lid. #
Never drive with the boot lid open. #
Close the boot lid. 444
Displaymessa ges and warning/indicator lamps

Au
tomatic mir rorfo lding function
Ac tivating/deactivating......................... 13 2
Au tomatic transmission
DIRECT SELECT le ver............................. 15 0
Drive program display............................ 14 9
Drive programs...................................... 14 8
DY NA MIC SELECT switch...................... 14 8
Engaging drive position........................ .152
Engaging neutral................................... .151
Engaging pa rkposition.......................... 15 2
Engaging reve rsege ar........................... .151
Kickdown............................................... 154
Manual gear changing.......................... .153
St eering wheel gearshift paddles.......... 15 3
Tr ansmission position displa y................ 15 0
Tr ansmission position s..........................15 0
Au tomatic transmission (problem)
see Transmission (problem)
Axle load Perm issible............................................ 414
Tr ailer operation.................................... 429 B
Bad weather light...................................... 124Ball ne
ck
Fo lding out/in....................................... 220
BA S (Brake Assist Sy stem)....................... 17 0
Battery see Battery (vehicle)
Battery (k ey)
Re placing.................................................74
Battery (vehicle) Charging................................................ 384
Charging (Remo teOnline)...................... 13 9
No tes..................................................... 381
No tes (s tarting assis tance and
ch arging)............................................... 382
Re placing.............................................. 386
St arting assis tance................................ 384
Belt see Seat belt
Bic ycle rack
Load capacity........................................ 428
Tr ailer operation.................................... 224
Blind Spot Assist Activating/deactivating......................... 19 8
Fu nction................................................ 19 5Sy
stem limitations................................. 19 5
Blo wer
see Climate control
BlueTEC see AdBlue ®
Blue tooth ®
Information............................................ 258
Setting up an Internet connection.........3 23
Switching on/off.................................. .258
Switching profile (DUN/PAN)................ 324
Blue tooth ®
audio
Ac tivating.............................................. 339
De-authorising (de-regis tering) the
device.................................................... 340
Information............................................ 337
Overview............................................... 338
Sear ching for a track............................. 340
Sear ching for and auth orisingthe
device.................................................... 338
Selecting a media pla yer....................... 339
Switching device via NFC...................... 340
Bonnet Resetting (active bonnet)...................... 355 504
Index