engine MERCEDES-BENZ E-CLASS CABRIOLET 2021 Service Manual

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
(/ page220). 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 26
4
Ma intena nce and care

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 ldisp lay
can onlycalculat eth eser vice dueda te when
th ebat tery isconnect ed. #
Notedown theser vice duedatedispla yedon
th eins trument displaybef orediscon necting
th ebatt ery(/ page26 4). Engine
compartment Opening
andclosing thehood &
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. #
Open orclose thehood onlywhen ther e
is nobody inthehood's rang eof mo ve‐
ment. &
WARNIN GDang erofburnswhen open‐
ing thehood
If yo uopen thehood when theengine has
ove rheat edordur ing afire intheengine
com partmen t,yo uco uld come intoco ntact
wit hho tga ses orother escaping operating
fl uids. #
Beforeopen ingthehood, allowthe
engine 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.
Mak esur eof thefo llo wing beforeper form ing
ta sk sin theengine compartmen t: #
Swi tchth eignition off. Maint
enanc eand care265

#
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. 266
Maintenanc eand care

#
Push handle 1ofthehood catchupw ards
and liftth ehood byappr oximat ely15 in
(40 cm).
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 theon-
boar dcom puter
Re quirement s:
R The engin ehas been warmed up.
R The vehicle ispar kedon aleve lsur face.
R The engineisrunning atidle spe ed.
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 activ edr iving style.
On- boar dcom puter:
4 Service5
Engine OilLevel
Yo uwill see oneof thefo llo wing mess ages 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 1,1qts. andthebar dis‐
pla yfo rindica tingtheoil leve lon themulti‐
func 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 isdef ective or notcon nected. Maint
enanc eand care26
7

#
Con sult aqu alif ied spec ialistwo rkshop.
R Engine OilLevel System Currently Unavail. #
Close thehood.
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 l)of oil 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. 268
Maintenance andcare

#
Turn cap 1cou nter-cloc kwiseand remo ve
it. #
Addengin eoil. #
Replace cap1and turnit cloc kwise untilit
eng ages. #
Chec kth eoil leve lag ain (/ page26 7). Chec
kingthecoolant 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-clo ckwise to
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
(/ page338) Maint
enance andcare269

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. #
Allo wtheengine 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. #
Addwa sher fluid. 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 No
teson washing theve hicl ein acar wash &
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. *
NO
TEDama gefrom automatic braking If
one ofthefo llo wing functionsis switc hed
on, theve hicle brak es aut omatically incer‐
ta in situat ions:
R ActiveBr ak eAssi st
R ActiveDis tance AssistDIS TRONI C
R HOLD functio n
R ActivePa rking Assist 27
0
Maint enance andcare

Ke
ep childr enaway. Obser
vethis Opera tor's Manua l.
Obser vethefo llo wing ifyo udo notint endto use
th eve hicle overan extende dpe riod oftime:
R Activatest andb ymode .
R Alternat ivel y: con nectth ebatt eryto abat ‐
te ry charge rapp rove dby Mer cedes-Ben zor
consult aqu alif ied spec ialistwo rkshop to
discon nectth ebatt ery. No
teson star ting assistance andchargin g
th e12 Vbatt ery Ve
hicl eswith alithium-ion battery
When chargin gth ebatt eryand during star tin g
assis tance, alwa ys use thejum p-startconne c‐
tio npo int intheengine compartmen t. *
NO
TEDama getothebatt eryfrom over‐
vo ltag e When
chargin gusin gabat tery charge rwit h‐
out amaximu mchargin gvo ltag e, thebatt ery
or theon- boar delectr onics maybe damag ed. #
Onlyuse batterych arge rs wit hamax i‐
mum chargin gvo ltag eof 14.8 V. All
other vehicl es
When chargin gth ebatt eryand during star tin g
assis tance, alwa ys use thejum p-start connec‐
tion pointintheengine compartmen t.
* NO
TEDama getothebatt eryfrom over‐
vo ltag e When
chargin gusin gabat tery charge rwit h‐
out amaximu mchargin gvo ltag e, thebatt ery
or theon- boar delectr onics maybe damag ed. #
Onlyuse batterych arge rs wit hamax i‐
mum chargin gvo ltag eof 14.8 V. &
WARNIN GRisk ofexplosion from hydro‐
ge nga signiting
Ther eis adang erofhydrog en gasigniting
when chargin gth ebatt eryif th er eis ashor t
cir cuit orspar ksstar tto form . #
Mak esur eth at thepositiv ete rm inal of
th econ nect edbatt erydoes notcome
int ocon tact with vehicle parts. #
Neverpla ceme talobje ctsor tools ona
batt ery. #
The descr ibedorder ofthebatt ery
clam psmus tbe obser vedwhen con‐
nec tingand discon nectingth ebatt ery. #
When giving star tin gassis tance, alwa ys
mak esur eth at youon lyconnect bat‐
te ry term inals withident icalpolar ity. #
Dur ing star tin gassis tance, youmus t
obse rveth edescr ibedorder forcon‐
necting anddisconnecting thejum per
cable. #
Donotcon nect ordiscon nectthebat‐
te ry cla mp swhile theengine isrunning . 28
8
Brea kdo wnassist anc e

&
WARNIN GRisk ofexplosion during
ch argin gpr oce ssand star tin gassis tance
Dur ing thech argin gpr oce ssand star tin g
assis tance, thebatt eryma yre lease anexplo‐
siv ega smixtur e. #
Avoid fire ,open flames ,cr eat ing spar ks
and smoking. #
Mak esur eth er eis suf ficie ntventil a‐
tio n. #
Donotle an ove ra batt ery. &
WARNIN GRisk ofexplosion from afro‐
zen battery
A disc hargedbatt eryma yfreeze attemp era‐
tur es slightl yabo veorbelo wfreezing point.
Dur ing star tin gassis tance orbatter ych arg‐
ing ,bat tery gascan bereleased. #
Alw aysallo wabatt eryto thaw before
ch argin git or per form ing star tin gassis ‐
ta nce. If
th eindicat or/warning lampsintheins trument
clus terdo notlig ht up atlow temp eratur es,itis
ve ry likelyth at thedisc hargedbatt eryhas fro‐
zen .In this case youma yne ither jump-start the
ve hicle norcharge thebatt ery.
The service life of abatt eryth at has been
th awe dma ybe dramaticall yshor tened .The
st ar tin gch aract eristic sma ybe impair ed,espe ‐
ciall yat low temp eratur es.
It is recomme ndedthat youha ve ath aw ed bat‐
te ry checkedat aqu alif ied spec ialistwo rkshop.
All vehicl es
* NO
TEDama gecau sed bynum erou sor
ex tende datt em ptsto star tth eengine Nu
me rous orextende datt em ptsto star tth e
engine maydamag eth ecat alytic converter
due tonon-co mbusted fuel. #
Avoid numer ousand extende datt em pts
to star tth eengine. Obser
vethefo llo wing pointsdur ing star tin g
assis tance and when chargin gth ebatt ery:
R Onlyuse undamag edjum per cables/c harg‐
ing cables withasuf ficie ntcross -secti onand
insu late dte rm inal clam ps.
R Non-insulat edpar tsof thete rm inal clam ps
mus tno tcom eint ocon tact with other metal
par tswhile thejum per cable/c harging cable
is con nect edtothebatt ery/jum p-start con‐
nectio npoi nt.
R The jumper cable/c harging cable mustno t
com eint ocon tactwi th anypar tswhic hma y
mo vewhen theengine isrunning .
R Alw aysmak esur eth at nei ther youno rth e
batt eryis elect rostatic allych arge d.
R Keep away from fire and open flames .
R Donotlean overth ebatt ery.
Obser vetheadditional follo wing pointswhen
ch argin gth ebatt ery:
R Onlyuse batterych arge rs tested and
appr oved forMer cedes-Benz.
R Read thebatt erych arge r's oper ating instruc‐
tions beforech argin gth ebatt ery. Br
ea kdo wnassista nce 28
9

Obser
vetheadditional follo wing pointsdur ing
st ar tin gassis tance:
R Startin gassis tance mayonly beprov ided
using vehicles, batteries orother jumpstar t
de vic es wit hano min alvoltag eof 12 V.
R The vehicles mustno tto uc h.
R Vehicl eswith aga soline engine: Jump
st ar tth eve hicle onlywhen theengine and
ex haus tsy stem arecold. St
arting assistance andchargin gth e12 V
batt ery Re
quirement s:
R The vehicle issecur edwithth eelectr icpar k‐
ing brak e.
R Vehicl eswith automatic transmiss ion:
The transmis sionisin posi tion 005D.
R The igniti onand allele ctrical consumer sar e
swi tched off.
R The hood isopen. Ex
am ple:engine compartment #
Slid eco ver1 ofposi tiveclam p2 onthe
jum p-starting con nection point inthedir ec‐
tion ofthear row . #
Con nect posi tiveclam p2 onyour vehicle to
th epositiv epole ofthedonor batteryusing
th ejum per cable/c harging cable. Always begin
withpositiv eclam p2 onyour ow n
ve hicle firs t. #
During star ting assistance :st ar tth e
engine ofthedonor vehicle andrunat idle
spe ed. #
Connect theneg ativepole ofthedonor bat‐
te ry and grou nd point 3 ofyour ow nve hicle
by usin gth ejum per cable/c harging cable.
Begin withth edonor batteryfirs t. #
During star ting assistance :st ar tth e
engine ofyour ow nve hicle. #
Dur ing thech argin gpr oc ess :st ar tth e
ch argin gpr oce ss. #
Dur ing star ting assistance :le tth eengines
ru nfo rse veralmin utes. #
Dur ing star ting assistance :bef oredis con‐
necting thejum per cable, switchon anelec‐
tr ical consumer inyour ow nve hicle, e.g.the
re ar wind owheat eror lighting.
When thest ar tin gassis tance/c harging proce ss
is com plet e, per form thefo llo wing steps: 290
Breakdo wnassis tance