engine MERCEDES-BENZ C-CLASS CABRIOLET 2021 Service Manual

Mer
cede s‑AMG vehicl es:Cruis econtr olis
av ailable uptoamax imum speedof 155mp h
(250 km/h).
Displa yson themu ltifunct iondisp lay
R h (gray):cr uise control isselect edbut
no tye tacti vated.
R h (green): cruise control isactiv e.
A stor ed speed appear salong withth eh dis‐
pla y.
% The segment sbe tween thestor ed speed and
th eend ofthesegment displaylight upin
th espeedome ter.
Sy stem limit s
Cr uise control ma ybe unable tomaint ainthe
st or ed speed onuphill gradients. Thestor ed
speed isresumed whenthegr adient evensout.
Ch ang eint oalowe rge ar ingood timeon long
and steep downhill gradients. Take par ticular
no te ofthis when drivin galaden vehicle. By
doing so,youwill mak euse oftheengine' sbr ak‐
ing effect. Thisre lie vesth eload onthebr ak e
sy stem and preve nts thebr ak es from overheat‐
ing and wearing tooqu ickl y. Do
notus ecr uise contr olinthefo llo wing situa‐
tion s:
R Intraf fic situ ations whichrequ ire freq uent
ch ang esofspee d,e.g .in hea vytraf fic, on
wi nding roads.
R Onslippe ryroads. Accel erati ng can cause
th edr ive wheels tolose tract ion and the
ve hicle could then skid.
R Ifyo uar edr ivin gwhen visibilit yis poor .
Ope ratin gcr uis eco ntr ol &
WARNIN GRisk ofacci dent dueto stor ed
speed
If yo ucall upthestor ed speed andthis is
lo we rth an your cur rent spe ed,th eve hicle
deceler ates. #
Take intoacc ount thetra ffic situat ion
bef orecallin gup thestor ed speed. Re
quirement s:
R ESP®
mus tbe act ivat ed, but notint erve ning .
R The vehicle speed isat leas t15 mp h
(20 km/ h). R
The transmis sionisin positio n005B. Oper
atingcr uise contr ol #
Press thero ck er switc hesonthesteer ing
wheel control panel upordown tothe
desir edposition .
Ac tiv atin gcr uis eco ntr ol #
Select M with theright rock er switc h. 15
8
Driving and parking

obs
tacle and ther eis arisk ofalat eral collision,
a wa rning isissued andthesegment slight upin
color inthedispla y.
The segment colorchang esdepen dingon the
dis tance tothede tected obs tacle :
R Yello w: appr oximat ely1. 0 -2.0 ft
(30 -60 cm)
R Red:less than appr oximat ely1. 0 ft (30 cm)
In order forlat eral front orrear segm entsto be
displa yed, theve hicle mustfirs ttr ave la dis tance
of at leas tha lfof theve hicle length.Once the
ve hicle hastrave led thelengt hof theve hicle, all
of thelat eral front and rear segm entscan bedis‐
pla yed. Pa
rking AssistPA RK TRONI Cdisp lay: vehicles
wit hout asur round viewcam era
1 Operation alfron tand rear
2 Operation alfron t,re ar and sides
3 Obstacle detected atthefront right (yello w)
and rear (red) Pa
rking AssistPA RK TRONI Cdisp lay: vehicles
wit hasur round viewcam era
1 Operation alfron tand rear
2 Operation alfron t,re ar and sides
3 Obstacle sde tected atthefront right (red)
Sa vedobs tacle son thesides aredele tedin the
fo llo wing situat ions,fo rex am ple:
R Youpar kth eve hicle andswitc hof fth eigni‐
tion .
R Youopen thedoor s.
Af terth eengine isrestar ted, obs tacle son the
sides mustbe detected again bef oreane w
wa rning can beissued. 19
2
Driving and parking

ASS
YSTPL US service interva ldisp lay Fu
nction oftheASS YSTPL US service interva l
displ ay The
ASSYSTPL US service interva ldispla yon the
Ins trument Displaypr ov ides informatio non the
re maini ngtime ordis tance before thene xt
ser vice duedate.
Yo ucan hide this ser vice displa yusing thebac k
butt ononthelef t-hand sideofthesteer ing
wheel.
Depen dingonhowtheve hicle isused, the
ASS YSTPL US service interva ldispla yma y
shor tenth eser vice interva l,e.g. inthefo llo wing
cases :
R Mainl yshor t-dis tance drivi ng
R Whe nth eengine isoftenleft idling forlong
per iods
R Intheeve ntoffreq uent col dstar tphase s
Mer cedes-Ben zre comme ndsavoiding such
oper ating condit ions.
Yo ucan obtain informat ionconcernin gth eser v‐
icing ofyour vehicle from aqu alif ied spec ialist wo
rkshop, e.g.anaut hor ized Mercedes-Benz
Cent er. Displa
yingtheser vice dueda te On-boar
dcom puter:
4 Service 5
ASS YST PLUS
The next ser vice duedateis displa yed. #
Toexitth edisp lay: press thebac kbutt on
on thelef t-hand sideofthesteer ing wheel.
Bear inmind thefo llo wing relat ed topic:
R Oper ating theon- board computer
(/ page202). Inf
ormat iononregular maintenance work *
NO
TEPrema turewe arthro ugh failur eto
obser veser vice duedates Maint
enance workwhic his no tcar ried out at
th eright time orincom pletely ca nlead to
inc reased wearand damag eto theve hicle. #
Adher eto thepr escr ibed service inter‐
va ls. #
Alw aysha ve thepr escr ibed maint e‐
nanc ewo rkcar ried out ataqu alif ied
spec ialistwo rkshop. Special
service requ irement s The
prescr ibed service interva lis based onnor ‐
mal opera tionoftheve hicle. Maintenance work
will needto be per form ed mor eof tenif th eve hi‐
cle isoper ated under arduous conditions or
incr eased loads.
The ASSYSTPL US service interva ldispla yis onl y
an aid. Thedriver oftheve hicle bearsre sponsi‐
bility asrega rdsto whe ther maint enanc ewo rk
nee dstobe per form ed mor eof tenth an spec i‐
fi ed based ontheactual operating conditions
and/or loads.
Ex am ples ofarduous operating conditions :
R regular citydriving withfreq uent intermedi‐
at estops
R mainly short-distance drivi ng 31
6
Maint enance andcare

R
freq uent operation inmount ainouste rrain or
on poor road sur faces
R whe nth eengine isoftenleft idling forlong
per iods
R oper ation inpar ticula rly dus tycond ition s
and /orif air -rec ircula tion mod eis freq uen tly
used
In these orsimilar operating conditions ,ha ve the
int erior airfilt er ,engin eair clean er,engin eoil
and oilfilt er etc. chang edmor efreq uent ly.The
tir es mus tbe checkedmor efreq uentl yif th e
ve hicle isoper ated under increased loads. Fur‐
th er information canbeobt ained ataqu alif ied
spec ialistwo rkshop. Batt
erydisconne ctionperiods The
ASSYSTPL US service interva ldispla ycan
calc ulateth eser vice duedateonl ywhen the
batt eryis con nected. #
Notedown theser vice duedatedispla yedon
th eins trument displaybef orediscon necting
th ebatt ery(/ page31 6). Eng
inecom partment Ope
ningand clos ing the hood &
WARNIN GRisk ofacci dent dueto driv‐
ing withth ehood unlocked
The hood mayopen andblockyo ur vie w. #
Neverre lease thehood when driving. #
Beforeev erytrip, ensur eth at thehood
is loc ked. &
WARNIN GRisk ofacci dent andinjury
when openingand closingthehood
The hood maysuddenl ydr op intoth eend
position .
Ther eis arisk ofinjur yfo ran yone inthe
hood's rang eof mo vement. #
Donotopen orclose thehood ifth er e
is aper son inthehood's rang eof mo ve‐
ment. &
WARNIN GRisk ofburnswhen opening
th ehood
If yo uopen thehood when theengine has
ove rheat edorwhen ther eis afire inthe
engine compartmen t,th efo llo wing situat ions
ma yocc ur:
R Youco uld come intoco ntact withho t
ga ses.
R Youco uld come intoco ntact withot her
ho t,escaping operating fluids. #
Beforeopen ingthehood, allowthe
ove rheat edengine tocool down. #
Intheeve ntofafire intheengine com‐
par tmen t,ke ep thehood closed and
call thefire ser vice. &
WARNIN GRisk ofinju rydue tomo ving
par ts
Com ponents intheengine compartmen tma y
con tinue running orstar tup sudden ly,ev en if
th eignition isswitc hedoff. Maint
enanc eand care 317

Mak
esur eof thefo llo wing beforeper form ing
ta sk sin theengine compartmen t: #
Swi tchth eignition off. #
Neverre ac hint oth edang erzon esur‐
ro und ingmovingco mp onent s,e.g. the
ro tatio nar ea ofthefa n. #
Remo vejewe leryand watche s. #
Keep items ofclo thing and hair away
fr om moving parts. &
WARNIN GRisk ofinju ryfrom touc hin g
co mp onent sunder voltag e
The ignit ionsystem and thefuel injec tion
sy stem workund erhigh voltag e. Youco uld
re cei vean elec tric shoc k. #
Neverto uc hco mp onent sof theignition
sy stem orthefuel injec tionsystem
when theignition isswitc hedon. &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntpar tsintheengine com‐
par tmen tcan bevery hot,e.g. theengine,
th ecooler andpartsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN GRisk ofinju ryfrom using the
winds hieldwiper swhile theengine hood
is open
When theengine hoodisopen andthewind‐
shield wipersar ese tin mo tion ,yo ucan be
tr apped bythewiper linkage. #
Alw aysswitc hof fth ewindshield wipers
and ignition beforeopening theengine
hood. Opening
thehood #
Torelease thehood, pullonhandle 1. 31
8
Maint enance andcare

#
Push handle 1ofthehood catchupw ards
and liftth ehood untilitopens automaticall y.
Closing thehood #
Lowe rth ehood toaheigh tof aroun d8 in
(20 cm)and then allo witto fall, appl ying a
litt leforc eas youletit go. #
Ifth ehood canstill be lifte dslightl y,open
th ehood again and close itwit halittle more
fo rc euntil iteng ages cor rectl y. Engine
oil Chec
kingtheengine oilleve lusing theoil
dip stick &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntpar tsintheengine com‐
par tmen tcan bevery hot,e.g. theengine,
th ecooler andpartsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. Re
quirement s:
R The engin ehas anoildips tick.Ifno t,th e
engine oilleve lcan becheckedonl ywit hth e
on-boar dcom puter(/ page320) . Depending
ontheengine, theoil dips tickma ybe
ins talled intheengine compartmen tin dif fere nt
lo cati ons.
The waitin gtim ebef orech ecking theoil leve l
when theengine isat nor mal oper ating temp era‐
tur eis five minut es. #
Park theve hicle onaleve lsur face. #
Pulloil dips tic k1 outand wipe off. Ma
intena nce and care 31
9

#
Slowly slide oildi ps tic k1 intoth eguide
tube tothestop, and pullitout again afte r
about thre esecon ds.
R Oilleve lis cor rect:oil leve lis be tween 2
and 3.
R Oilleve lto olow: oil leve lis at 3 or
belo w.
R Oilleve lto ohigh: oilleve lis abo ve2 . #
Ifth eoil leve lis toolow, add 1.1 US qt
(1 liter) ofengine oil. #
Ifth eoil leve lis toohigh, drain offexc ess
engine oil.Consult aqu alif ied spec ialist
wo rkshop.
Chec kingtheengine oilleve lusing theon-
boar dcom puter
Re quirement s:
R The engin ehas anoilleve lsen sor.If no t,th e
engine oilleve lcan becheckedonl ywit hth e
oil dips tick(/ page31 9).
R The engine hasbeenwa rmed up.
R The vehicle ispar kedon aleve lsur face.
R The engineisrunning atidle spe ed. R
The hoodis clo sed .
The engineoille ve lis de term ined during drivin g.
De term inin gth eengine oilleve lcan take up to
30 minut eswit hanor mal driving style and even
long erwit han act ive dr ivin gst yle.
On- boar dcom puter:
4 Service5
Engine OilLevel
One ofthefo llo wing mess ages will appear on
th emultifunc tiondispla y:
R Measuring Engine OilLevel.. .:measur ement
of theoil leve lis no tye tpo ssi ble. #
Repeat there qu estaf te ra maximu mof
30 minut es'driving.
R Engine OilLevel OKand thebar displa yfo r
indic atingth eoil leve lon themultifunc tion
displa yis green and isbe tween "min" and
"max": theoil leve lis cor rect.
R Engine OilLeve lAdd 1.0land thebar displa y
fo rindica tingtheoil leve lon themultifunc ‐
tion displa yis orang eand isbelo w"min": #
Add1.1 US qt(1l)of engine oil. R
Red uce Engine OilLevel andthebar displa y
fo rindica tingtheoil leve lon themultifunc ‐
tion displa yis orang eand isabo ve"max ": #
Drain offan yex cess engineoilthat has been
added. Todo so, con sult aqu alif ied spec ialist
wo rkshop.
R For Engine OilLevel Switch Ignition On #
Switc hon theignition tocheckth eengine oil
le ve l.
R Engine OilLeve lSyst emInoperat ive:The oil
le ve lsen sor ismalfun ctionin gor notcon nec‐
te d. #
Consult aqu alif ied spec ialistwo rkshop.
R Engine OilLevel System Currently Unavail. #
Close thehood. 320
Maintenanc eand care

Re
filling engine oil &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntpar tsintheengine com‐
par tmen tcan bevery hot,e.g. theengine,
th ecooler andpartsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN GRisk offire and injuryfrom
eng ineoil
If eng ineoilcom esintocon tact with hot
com ponent partsintheengine compart‐
ment ,it ma yignit e. #
Mak esur eth at no eng ineoilisspille d
ne xt to thefiller open ing. #
Allo wtheengine tocool offand thor‐
oughl yclean theengine oilfrom com po‐
nen tpar tsbef orest ar tin gth eve hicle. *
NO
TEEngi nedama gecau sed byan
inc orrect oil filt er ,inc orrect oil oraddi‐
tiv es #
Donotus eengi neoilsor oil filt er s
whic hdo notcor respond tothespecif i‐
cation sex plicitl ypr escr ibed forth e
ser vice interva ls. #
Followtheins truction son theser vice
int erva ldispla yfo rch ang ingtheengine
oil and obser vethepr escr ibed chang e
int erva ls. #
Donotuse additiv es. *
NO
TEDama gecau sed byrefilling too
muc hengine oil To
omuc hengine oilcan damag eth eengine
or thecat alytic converter . #
Have excess engineoilremo vedat a
qu alif ied spec ialistwo rkshop. %
Depending ondriving style, theve hicle con‐
sumes upto0.9 USqt(0.8 liter) ofoil per
600 miles(1 000 km).The oilconsum ption ma
ybe higher than this when theve hicle is
ne wor ifyo ufreq uen tly dr ive at high engin e
spee ds. #
Turn cap 1cou nter-cloc kwiseand remo ve
it. #
Addengin eoil. #
Replace cap1and turnit cloc kwise untilit
eng ages. Maint
enanc eand care32
1

#
Chec kth eoil leve lag ain (/ page31 9). Ch
ecking thecoolant leve l &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntpar tsintheengine com‐
par tmen tcan bevery hot,e.g. theengine,
th ecooler andpartsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN GRisk ofscal ding from hot
cool ant
If yo uopen thecap, youco uld bescalded. #
Letth emo torcool down beforeopening
th ecap. #
When opening thecap, wearprotect ive
gl ove sand safetygl asses . #
Open thecap slowlyto release pres‐
sur e. #
Park theve hicle onaleve lsur face. #
Checkth ecoolant temp eratur edispla yin the
ins trumen tclus ter.
The coolant temp eratur emus tbe inthebo t‐
to m quarterof thete mp eratur edispla y. #
Slowly turncap 1cou nter-cloc kwiseto
re lease overpressur e. #
Continue turning cap1count er-cloc kwise
and remo veit.
The coolan tle ve lis cor rect inthefo llo wing
cases :
R Ifth eengine iscold, thecoolant isup to
mar kerbar 2.
R Ifth eengine iswa rm,th ecoolant isup to
0.6 in(1.5 cm) over mar kerbar 2. #
Ifnecessar y,add coolant that has been
appr ovedfo rMer cedes-Benz.
% Further information oncoolant
(/ page393) Re
filling thewindsh ieldwasher system &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntpar tsintheengine com‐
par tmen tcan bevery hot,e.g. theengine,
th ecooler andpartsof theex haus tsy stem. 322
Maintenanc eand care

#
Allow theengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN G‑Ri sk offire and injuryfrom
wind shieldwa sher concen trat e
Wi ndsh ield wa sher concen trat eis highl y
fl ammab le.Itcoul dign ite if it com esinto
con tact with hotengine component partsor
th eex haus tsy stem. #
Mak esur eth at no wind shieldwa sher
concen trat espills outnext to thefiller
open ing. #
Remo vecap 1bytheta b. #
Refill wa sher fluid.
% Further information aboutthewindshield
wa sher fluid (/ page39 4) Ke
eping theair -water duct free #
Keep thear ea between thehood andthe
winds hieldfree ofdepos its,e.g .ice, snow
and leaves. Cleani
ngand care Inf
ormat iononwashing theve hicl ein acar
wa sh &
WARNIN GRisk ofacci dent dueto
re duced braking effect afte rwa shing the
ve hicle
The braking effect isreduced afte rwa shing
th eve hicle. #
Afterth eve hicle hasbeen washed,
br ak ecar efully whilepaying attention to
th etraf fic condi tions untilth ebr aking
ef fect hasbee nful lyrestor ed. Maint
enance andcare323