engine MERCEDES-BENZ C-CLASS CABRIOLET 2018 Repair Manual

Re
quirements forth e ins tallation:
R The ignition is switched on.
R The engine is not running.
R Notes and warnings ha vebeen read and
accep ted.
R The parking brake is applied.
If all requirements are met, the update will be
ins talled. The multimedia sy stem cann otbe
operated while the update is being ins talled and
ve hicle functions are restricted.
If er rors should occur during the ins tallation, the
multimedia sy stem automatically attem ptsto
re store the pr evious version. If restoration of the
pr ev ious version is not possible, a symbol
appears on the cent reconsole displ ay. Please consult a
qualified specialist workshop to
re solve the problem. Re
set function Multimedia sy
stem:
0018 System 0019
Reset
Pe rsonal data is dele ted, forex ample:
R Station presets
R Connec ted mobile phones 0007
Select Yes.
If PIN pr otection is activated, a prom ptappears
asking if you also wish torestore this to thefa c‐
to ry settings during a reset. 0007
Select Yes. 0007
Enter the cur rent PIN.
The PIN is reset.
or 0007
Select No.
The cur rent PIN stay sth e same af terre set‐
ting.
0009 Ifyo u ha veforg ottenyo ur PIN, a Mercedes-
Benz service centre can deactivate the PIN
pr otection foryo u.
A prom ptappears again asking whe ther you
re ally wish toreset. 0007
Select Yes.
The multimedia sy stem is reset tothefa ctory
settings. Fi
t & Healthy ENE
RGIZING comfort 298
Multimedia sy stem

ASS
YST PLUS se rvice inter val display Fu
nction of the ASS YST PLUS se rvice inter val
displ ay The ASS
YST PLUS service inter val display on the
instrument display pr ovides information on the
re maining time or dis tance be fore the next
service due date.
Yo u can hide this service message using the
back button on the left-hand side of thesteering
wheel.
Depending on how theve hicle is used, the
ASS YST PLUS service inter val display may
shor tenth e service inter val, e.g. in thefo llowing
cases:
R mainly short-dis tance driving
R when the engine is of ten le ftidling for long
periods
R intheeve nt of frequent cold start phases
R Vehicles with a diesel particulate filter: in
th eev ent of frequently inter rupted rege nera‐
tion of the diesel particulate filter Mercedes-Benz
recommends avoiding such
operating conditions.
Yo u can obtain fur ther information concerning
th e servicing of your vehicle from a qualified
specialist workshop, e.g. a Mercedes-Benz
Service Centre. Displaying
the service due da te On-board computer:
0018 Service 0019
ASSYST PLUS
The next service due date is displa yed. 0007
Toexitth e displa y:press the back button
on the left-hand side of thesteering wheel.
Make sure toobser vethefo llowing fur ther rela‐
te d subjec t:
R Operating the on-board computer
(0013 page 252). Information on
regular maintenance work 000E
NO
TEPremature wearthro ugh failure to
obser veservice due dates Service
workwhich is not car ried out at the
ri ght time or incomple tely can lead to
inc reased wear and damage totheve hicle. 0007
Alw ays obser vethe prescribed service
inter vals. 0007
Alw ays ha vethe prescribed service
wo rkcar ried out at a qualified specialist
wo rkshop. Special service
requ irements The prescribed service inter
val is based on nor‐
mal operation of theve hicle. Maintenance work
will need tobe per form ed more of ten if theve hi‐
cle is operated under arduous conditions or
increased loads.
The ASS YST PLUS service inter val display is only
an aid. The driver of theve hicle bears responsi‐
bility as rega rdsto whe ther maintenance work
needs tobe per form ed more of tenth an speci‐ Main
tenance and care 387

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 se rvice inter val display
can only calculate the service due da tewhen
th e bat tery is connected. 0007
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (0013 page 387). Engine compartment
Ac
tive bonn et(pedestrian pr otection) Operation of
the active bonnet (pedestrian
pr otection)
In cer tain accident situations, therisk of injury
to pedestrians can be reduced bythe actuation
of the active bonn et. The rear area of the bonn et
is raised byappr oximately 85 mm.
Fo rth e drive tothewo rkshop, reset the trig‐
ge red active bonn etyourself. Af terth e active
bonn ethas been triggered, pedestrian pr otection
may be limited.
A qu alified specialist workshop must re-ins tate
th e full functionality of the active bonn et. The active bonnet is not
available in all coun‐
tries.
Re setting the active bonnet 000A
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. 0007
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. 388
Maintenance and care

0007
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. 0007
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/closing
the bonnet 000A
WARNING Risk of accident due todriv‐
ing with the engine bonn etunlo cked
An unloc ked engine bonn etmay open up
when theve hicle is in motion and block your
vie w. 0007
Never unlock the engine bonn etwhen
driving. 0007
Before every trip, ensure that the
engine bonn etis loc ked. 000A
WARNING Risk of accident and inju ry
when opening and closing the engine
bonn et
When opening or closing the engine bonn et,
it 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. 0007
Only open or close the engine bonn et
when there are no persons in the
engine bonn et's range of mo vement. 000A
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. 0007
Before opening the bonn et, allow the
engine tocool down. 0007
Intheeve nt of a fire inthe engine com‐
partment, keep the engine bonn et
closed and call thefire service. 000A
WARNING Risk of inju rydue tomoving
parts
Cer tain components in the engine compart‐
ment may continue tomo veor suddenly
mo veagain even af terth e ignition has been
switched off, e.g. the cooler fan.
Ma kesure of thefo llowing before per form ing
ta sks in the engine compartmen t: 0007
Switch the ignition off. 0007
Neverto uch the danger zone sur round‐
ing moving co mponent parts, e.g. the
ro tation area of thefa n. 0007
Remo vejewe llery and watches. 0007
Keep items of clo thing and hair away
from moving parts. Maintenance and care
389

000A
WARNING Risk of inju ryfrom touching
co mp onent parts under voltage
The ignition sy stem and the fuel injection
sy stem workunder high voltage. If youto uch
co mp onent parts which are under voltage,
yo u could recei vean electric shoc k.0007
Neverto uch co mponents of the ignition
sy stem or the fuel injection sy stem
when the ignition is switched on. 000A
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. 0007
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. 000A
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. 0007
Alw ays switch off the windscreen wip‐
ers and ignition before opening the
engine bonn et. 0007
Toopen: pullthe le ver1 torelease the
bonn et. 390
Maintenance and care

0007
Push the handle 1ofthe bonn etcatch
up wa rds and lift the bonn etby appr oximately
40 cm. 0007
Toclose: lowe rth e bonn etand let it fall from
a height of appr oximately 20 cm. 0007
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 000A
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. 0007
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. Re
quirements:
R the engine must ha vean oil dipstic k.If not,
th e engine oil le vel can be checked only with
th e on-board computer (0013 page 392).
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. 0007
Park theve hicle on a le vel sur face. 0007
Pull oil dipstick 1out and wipe off. 0007
Slowly slide oil dipstick 1into the guide
tube tothestop, and take it out again af ter
appr oximately 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. Maintenance and care
391

R
Oil le velto o high: oil le vel is abo ve2 . 0007
Ifth e oil le vel is too lo w,top up with 1 litre of
engine oil. 0007
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:
The engine must ha vean oil le vel sensor. If not,
th e engine oil le vel can be checked only with the
oil dipstick (0013 page 391).
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.
In order torecei veare sult as quickly as possi‐
ble:
R warm upthe engine
R park theve hicle on a le vel sur face
R leave the engine running at idling speed On-board compu
ter:
0018 Service 0019
Engine oil level
Yo u will see one of thefo llowing messages on
th e multifunction display:
R Engine oil level Measuring now : measure‐
ment of the oil le vel is not yet possible. 0007
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": 0007
Top up with 1 l 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": 0007
Drain off excess engine oil that has been
added. Consult a qualified specialist work‐
shop.
R For engine oil level turn on ignition: 0007
switch on the ignition tocheck the engine oil
le ve l.
R Engine oil level System inoperative : sensor
fa ulty or not inser ted. 0007
Consult a qualified specialist workshop.
R Engine oil level System currently unavail. : 0007
close the bonn et.
To pping up engine oil 000A
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. 0007
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. 392
Maintenance and care

000A
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. 0007
Make sure that no engine oil is spilled
next tothefiller opening. 0007
Allow the engine tocool off and thor‐
oughly clean the engine oil from compo‐
nent parts before starting theve hicle. 000E
NO
TEEngine dama gecaused byan
incor rect oil filter, incor rect oil or addi‐
tives 0007
Do not use engine oils or oil filters
which do not cor respond tothe specifi‐
cations explicitly prescribed forthe
service inter vals. 0007
Do not alter the engine oil or oil filter in
order toachie velonger change inter vals
th an presc ribed. 0007
Do not use additives. 0007
Follow the instructions in the service
inter val display rega rding the oil
ch ange. 000E
NO
TEDama gecaused bytopping up too
much engine oil To
o much engine oil can damage the engine
or the catalytic con verter. 0007
Have excess engine oil remo ved at a
qu alified specialist workshop. 0007
Turn cap 1anti-clockwise and remo veit. 0007
Top up the engine oil. 0007
Replace cap 1and turn it clockwise as far
as it will go. 0007
Check the oil le vel again (0013 page 391). Maintenance and care
393

Checking
the coolant le vel 000A
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. 0007
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. 000A
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. 0007
Before opening the bonn et, allow the
engine tocool down. 0007
Intheeve nt of a fire inthe engine com‐
partment, keep the engine bonn et
closed and call thefire service. 000A
WARNING Risk of scalding from hot
coolant
The engine cooling sy stem is pressurised,
particularly when the engine is warm. If you
open the cap, you could be scalded byhot
coolant spr aying out. 0007
Let the engine cool down before open‐
ing the cap. 0007
When opening the cap, wear pr otective
gl ove s and saf etygl asses. 0007
Open the cap slowly torelease pres‐
sure. 0007
Park theve hicle on a le vel sur face. 0007
Check the coolant temp erature display in the
instrument clus ter.
The coolant temp erature must be below
70 °C. 0007
Slowly turn cap 1anti-clockwise torelie ve
ov erpressure. 394
Maintenance and care

0007
Continue turning cap 1anti-clockwise and
re mo veit.
The coolant le vel is cor rect:
R ifth e engine is cold, up tomar ker bar 2
R ifth e engine is warm, up to1.5 cm over
mar ker bar 2 0007
If necessar y,top up with coolant that has
been appr ovedby Mercedes-Benz.
R Further information on coolant
(0013 page 466). To
pping up the windsc reen washer sy stem 000A
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. 0007
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. 000A
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. 0007
Before opening the bonn et, allow the
engine tocool down. 0007
Intheeve nt of a fire inthe engine com‐
partment, keep the engine bonn et
closed and call thefire service. 000A
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. 0007
Make sure that no windsc reen washer
concentrate spills out next tothefiller
opening. 0007
Remo vethe cap 1bytheta b. 0007
Top up thewa sher fluid. Ke
eping the air-water duct free 0007
Keep the area between the bonn etand the
windscreen free of deposits, e.g. ice, sn ow
and lea ves. Maintenance and care
395