MERCEDES-BENZ C CLASS 2021 Repair Manual

#
Mak esur eth at there ar ben chseat, the
re ar seat andtheseat backres tar e
eng aged bef oreeve rytrip . If
th elef tand right seat backres ts areno t
eng aged and lockedin place, this will besho wn
on themultifunc tiondispla yon theins trument
clus ter.
If th ecent erseat backres tis no teng aged and
loc kedin place, there dloc kve rificati onindi ca‐
to rwil lbe visib le.
When install ing abel t-secur edchild
re stra int system, obser vethefo llo wing:
0073 Alw
ayscom plywit hth emanuf acturer's
ins tallation andoper atingins truct ions for
th ech ild restra int system used.
0073 When
usingawe ight categor y0/0+
bab ycar seat andawe ight categor yI
re ar wa rd-faci ng child restra int system
on are ar seat :adju stthefront seat sothat
th eseat does notto uc hth ech ild restra int
sy stem.
0073 When
usingawe ight categor yIfo rw ard-
fa cing child restra int system: remo vethe head
restra int from there spectiv eseat, if
possible .
Af terth ech ild restra int system has been
re mo ved, replace thehead restra int sag ain
immed iatelyand adjus tth em correctly .
0073 The
backrest of thefo rw ard-f acin gch ild
re stra int system mus t,as faras possi ble,be
re sting ontheseat backres tof there ar
seat .
0073 If
th ehead restra int ofthech ild seat cannot
be fullyex tende dwh en itis ins talled inthe
ve hicle, this will result inrestrictions onthe
maximu msize setting forch ild restra int sys‐
te ms inwe ight categor yII or III.
Cont actwithth ero of when thehead
re stra int isfull yex tende dand lock ed in
place willnotre sult inanyre strictions on
us e.
0073 The
child restra int system mus tno tbe put
under stra in be tween thero of and theseat
cushion and/orbeinstalled facing the
wr ong direct ion. Wher eposs ible, adjus tth e
seat cushion inclination accordingly. 0073
The
child restra int system mus tno tbe put
under stra in by thehead restra int .Ad jus t
th ehead restra int sas appr opriate.
0073 Mak
esur eth at thech ild's feet do notto uc h
th efront seat. Ifneces sary,mo vethefront
seat slightl yfo rw ards.
The seat beltson thefo llo wing seats areeq uip‐
ped withaspec ialseat beltretract or:
R Front passeng erseat
R Rear seat s
When enabled,thespecial seatbeltretract or
ens ures that theseat belts ofthefront
passeng erseat andrear seat sdo notslac ken
once thech ild restra int system issecur ed
(/ page54 ). #
Installth ech ild restra int system.
The entire base ofthech ild restra int system
mus talw aysre st on thesitt ing surface ofthe
re ar seat . #
Alw aysmak esur eth at theshoulder belt
st ra pis cor rectly routed from theseat belt Occ
upant safety 59

outle
tof theve hicle totheshoulder belt
guide onthech ild restra int system.
The shoulder beltstra pmus tbe routed for‐
wa rdsand down wardsfrom theseat beltout‐
le t.
No teson rear wa rd-faci ng and forw ard-f acin g
ch ild restra int systems onthefront
pa sseng erseat &
WARNIN GRisk ofinju ryor deat hwhen
using are ar wa rd-faci ng child restra int
sy stem while thefront passeng erairbag
is enabled
If yo usec ureach ild inare ar wa rd-faci ng
ch ild restra int system onthefront passeng er
seat andthePA SSENGER AIRBAGOF Find i‐
cat orlam pis off,th efront passeng erairbag
can deplo yin theev ent ofan acciden t.
The child could bestru ck bytheairbag.
Alw aysensur eth at thefront passeng erair‐
bag isdisabled. ThePASSENGER AIRBAG
OFF indicat orlam pmus tbe lit. NEVER
useare ar wa rd-faci ng child restra int
sy stem onaseat withan ENABL EDFRONT
AIRB AG.Thi scan result intheDE ATHof or
SERIOU SINJU RYtotheCH ILD. Obser
vethespecif icins truction sfo rth ere ar‐
wa rd-faci ng and forw ard-f acin gch ild restra int
sy stems (/page60).
Alw aysobser vethest atus ofthefront passeng er
airbag onthePA SSENGER AIRBAGOF Find ica‐
to rlam p:
R When using are ar wa rd-faci ng child restra int
sy stem onthefront passeng erseat, thefront
passeng erairbag mustalw aysbe disabl ed.
This isonl yth ecase ifth ePA SSENGER AIR
BA GOF Find icat orlam pis lit con tinuousl y
(/ page46) .
R Ifth ePA SSENGER AIRBAGOF Find icat or
lam pis off,th efront passeng erairbag isena‐
bled. Thefront passeng erairbag maydeplo y
dur ing anacciden t. Secur
ingthech ild restra int system withth e
seat beltonthefront passeng erseat
When installing abelt- secur edchild restra int
sy stem onthefront passeng erseat, always
obser vethefo llo wing:
0073 Obser
vetheno teson rear wa rd-faci ng and
fo rw ard-f acin gch ild restra int systems on
th efront passeng erseat (/page60).
0073 Obser
vethech ild restra int system manuf ac‐
tur er's installation andoper atingins truc‐
tion s.
0073 When
usingafo rw ard-f acin gch ild restra int
sy stem inwe ight categor yI: re mo vethe
head restra int from there spectiv eseat, if
possible .
Af terth ech ild restra int system has been
re mo ved, replace thehead restra int sag ain
immed iatelyand adjus tth em correctl y.
0073 The
backres tof thefo rw ard-f acin gch ild
re stra int system mus t,as faras possi ble,be
re sting ontheseat backres tof thefront
passeng erseat.
0073 If
th ehead restra int ofthech ild seat cannot
be fullyex tende dwh en itis ins talled inthe 60
Occupant safety

ve
hicle, this will result inrestrictions onthe
maximu msize setting forch ild restra int sys‐
te ms inwe ight categor yII or III.
Cont actwithth ero of when thehead
re stra int isfull yex tende dand lock ed in
place willnotre sult inanyre strictions on
us e.
0073 The
child restra int system mus tno tbe put
under stra in be tween thero of and theseat
cushion and/orbeinstalled facing the
wr ong direct ion.
0073 The
child restra int system mus tno tbe put
under stra in by thehead restra int .Ad jus t
th ehead restra int sas appr opriate.
0073 Ne
verpla ceobjects (e.g.cushi ons)under or
behi ndthech ild restra int system.
The seat beltonthefront passeng erside is
eq uipped withaspecial seatbeltretract or.
Wh enena bled ,th especial seatbeltretract or
ens ures that theseat beltdoes notslac kenonce
th ech ild seat issecur ed(/ page54 ). #
Setth efront passeng erseat asfarbac kas
possi bleand movetheseat intoth ehighes t
position ifpossible. #
Fully re tract theseat cushion lengthadjus t‐
ment . #
Adjus tth eseat cushion inclination sothat
th efront edgeof theseat cushion isin the
highes tposition andthebac kedg eof the
seat cushion isin thelowe stposition . #
Setth eseat backres tto themos tve rtical
posit ionpossible . #
Installth ech ild restra int system.
The entire base ofthech ild restra int system
mus talw aysre st on thesitt ing surface ofthe
fr ont passeng ersea t. #
Alw aysmak esur eth at theshoulder belt
st ra pis cor rectly routed from theseat belt
outle tof theve hicle totheshoulder belt
guide onthech ild restra int system.
The shoulder beltstra pmus tbe routed for‐
wa rdsand down wardsfrom theseat beltout‐
le t. #
Ifneces sary,adjus tth eseat beltoutle tand
th efront passeng erseat accor dingly. Child
safetyloc ks Ac
tiv atin gor deac tivatin gthe child safety
loc kfo rthe rear door s &
WARNIN GRisk ofacci dent andinjury
due tochildr enleftunat tende din the
ve hicle
If ch ildr enarelef tunsuper visedintheve hi‐
cle, they cou ld,in pa rticular :
R open doors,ther eb yendang ering other
per sons orroad user s.
R getou tand bestru ck byoncom ingtraf‐
fi c.
R ope rate vehicle equipment andbecome
tr apped, forex am ple.
In addit ion,th ech ildr encould alsosetth e
ve hicle inmo tion, forex am ple by:
R releasing thepar king brak e.
R chang ingthetra nsmiss ionposition .
R star tin gth eve hicle. Occupant
safety 61

#
Neverlea vechildr enunat tende din the
ve hicle. #
When leaving theve hicle, alwaysta ke
th eSmar tKey wit hyo uand lockth e
ve hicle. #
Keep theve hicle SmartKey out ofreac h
of childr en. &
WARNIN GDang ertolife due toexpo‐
sur eto extreme heat or col din theve hi‐
cle
If people, particular lych ildr en, areex posed
to extreme temp eratur esove ran extende d
pe riod oftime, ther eis arisk ofser ious
injur yor dang ertolife. #
Neverlea veper sons, childr eninpar tic‐
ular ,unat tende din theve hicle. &
WARNIN GRisk ofacci dent andinjury
due tochildr enleftunat tende din the
ve hicle
If ch ildr enaretra veling intheve hicle, they
cou ld,in pa rticular :
R Open doors,ther eb yendang ering other
per sons orroad user s.
R Getout and bestru ck byoncom ingtraf‐
fi c.
R Ope rate vehicle equipment andbecome
tr apped, forex am ple. #
Alw aysactiv ateth eins talled child
saf etyloc ksifch ildr enaretra veling in
th eve hicle. #
Neverlea vechildr enunat tende din the
ve hicle. #
When leaving theve hicle, alwaysta ke
th eSmar tKey wit hyo uand lockth e
ve hicle. Ther
ear ech ild safetyloc ksforth ere ar door s
and there ar side windows. The
child safetyloc kon there ar door ssec ures
eac hdoor separat ely. The door scan nolong er
be opened from theinside. #
Press theleve rin dir ection 1(activ ate) or
2 (dea ctivate). #
Mak esur eth at thech ild safetyloc ksare
wo rking proper ly. 62
Occupant safety

Ac
tiv atin gor deac tivatin gthe child safety
loc kfo rthe rear side windo ws #
Toactiv ate/ deacti vate:pr ess button 2.
The rear side windowcan beope ned or
clos edinthefo llo wing cases :
R Indicat orlam p1 islit:via theswitc hon
th edr iver's door R
Indic ator lam p1 isoff:via theswitc hon
th ecor responding rear door ordriver' s
door No
teson pets intheve hicl e &
WARNIN GRisk ofacci dent andinjury
due toanim alsleftuns ecur edorunat ‐
te nde din theve hicle
If yo ulea veanim alsintheve hicle unatten‐
ded orunsecur ed,they cou ldpos siblypress
butt ons orswitc hes.
An animal may:
R Activateve hicle equipment andbecome
tr apped, forex am ple
R Swit chsystems onoroffand endang er
ot her road user s
Un secur edanimals maybe throw nar ou nd in
th eve hicle intheeve ntofan acci dent or
su dd en steer ing and braking maneuv ersand
injur eve hicle occupants inthepr ocess. #
Neverlea veanim alsintheve hicle unat‐
te nde d. #
Alw ayscor rectly secu reanim alswhile
dr ivin g,e.g .usin gasuit able anim alcar ‐
ri er . Occ
upant safety 63

Smar
tKey Ov
ervie wof Smar tKey functio ns &
WARNIN GRisk ofacci dent andinjury
due tochildr enleftunat tende din the
ve hicle
If ch ildr enarelef tunsuper visedintheve hi‐
cle, they cou ld,in pa rticular :
R open doors,ther eb yendang ering other
per sons orroad user s.
R getou tand bestru ck byoncom ingtraf‐
fi c.
R ope rate vehicle equipment andbecome
tr apped, forex am ple.
In addit ion,th ech ildr encould alsosetth e
ve hicle inmo tion, forex am ple by:
R releasing thepar king brak e.
R chang ingthetra nsmiss ionposition .
R star tin gth eve hicle. #
Neverlea vechildr enunat tende din the
ve hicle. #
When leaving theve hicle, alwaysta ke
th eSmar tKey wit hyo uand lockth e
ve hicle. #
Keep theve hicle SmartKey out ofreac h
of childr en. *
NO
TEDama getotheSmar tKey cau sed
by magne ticfields #
Keep theSmar tKey away from stro ng
ma gne ticfields. Smar
tKey wit hpanic alarm
1 Locks 2
Indicat orlam p
3 Unloc ks
4 Opens/closes thetrunk lid
5 Panic alar m
% Ifind icatorlam p2 does notlig ht up afte r
pr essing theÜ orß button,thebat‐
te ry iswe ak orposs iblydisc harged. Re place
th ebatt eryas soon aspossible.
Re place theSmar tKey batt ery(/ page66).
The Smar tKey loc ksand unlocksth efo llo wing
com pone nts:
R Doo rs
R Fuelfiller flap
R Trunk lid
If th eve hicle isno topened within appr oximat ely
40 seco ndsafte runloc king,itloc ksagain. Anti-
th eftpr otect ion isarmed again.
Do notke ep theSmar tKey toget her withelec‐
tr onic devices orme talobje cts. This canaffect
th eSmar tKey 's functionality . 64
Opening andclosing

Ac
tiv atin g/deac tivatin gthe acoustic lock ing
ve rificat ion signa l Mult
imed iasystem:
4 Vehicle 5
î Vehicle Setting s
5 Aco ustic Lock #
Activate0073 ordeacti vate 0053 thefunc tion. Ac
tiv atin g/deac tivatin gthe pani calar m Re
quirement s:
R The ignit ionisswitc hedoff. #
Toactiv ate: press butt on1 forapp rox‐
ima tely one second.
A visual andaudibl ealar mistrigg ered. #
Todeac tivate: briefly pr ess button1 again.
or #
Press thest ar t/ stop butt ononthecoc kpit,
wit hth eSmar tKey insid eth eve hicle. Changing
theunloc kingsettings Po
ssible unlockingfunctions oftheSmar tKey :
R Cen tralunlo cking
R Unloc kin gth edr iver's door andfuel filler flap #
Toswitc hbe tw een settings: press the
Ü andß buttonssimul taneousl yfo r
appr oximat elysix seco ndsuntilth eindicat or
lam pflashes twice.
Op tions ifth eunloc kingfunction forth edr iver's
door andfuel filler flap has been selected:
R Tounlo cktheve hicl ece ntr ally:press the
Ü buttontwice.
R Vehicl eswith KEYLESS-GO :if yo uto uc h
th einner surface ofthedoor handle onthe dr
iver's door ,onl yth edr iver's door andfuel
fi ller flap areunlo cked. Deactiv
atingtheSm artK ey functio ns If
yo udo notuse theve hicle oraSmar tKey for
an extende dpe riod oftime, youcan reduce the
ener gycon sum ption ofthere spectiv eSmar tKey .
To do so, deactiv ateth eSmar tKey functions. #
Todeac tivate: press theß buttononthe
Smar tKey twi ce inqu ick succ ession .
The Smar tKey indic ator lam pflashes twice
br ief lyand light sup once. #
Toactiv ate: press anybutt onontheSmar t‐
Ke y.
% When theve hicle isstar tedwit hth eSmar t‐
Ke yin thestor ag ecom partmen tof thecen‐
te rconsole, theSmar tKey functions are
au tomatical lyact ivat ed (/ page13 3). Op
ening an dclos ing 65

Re
mo ving /ins ertin gthe eme rgency key Re
mo ving the eme rgency key #
Press release knob 1.
Em erge ncy key2 ispush edout slightly. #
Pull outemer gency key2 untilit en gage sin
th eint ermediat eposition . #
Press release knob 1 again and fully
re mo veemer gency key2.
Inser ting theemer gency key #
Press release knob 1. #
Insertemer gency key2 totheint ermediat e
position orfull yuntil iteng ages. %
Youcan usetheint ermediat eposition of
emer gency key2 toatt achth eSmar tKey to
a ke yring. Re
plac ingthe Smar tKey batt ery &
DANG ER Serious damag eto healt h
caused byswallo wing batteries
Batt eries cont aintoxic and corrosiv esub‐
st anc es.Swallo wing batteries ma ycause
ser ious damag eto healt h.
Ther eis arisk offata linj ury. #
Keep batt eries out ofthere ac hof chil‐
dr en. #
Ifbatt eries aresw allo wed,seek medical
att ent ion immediat ely. +
ENVIR
ONMEN TALNO TEEnvironme ntal
da ma gedue toimproper disposal ofbat‐
te ries Batt
eries con tain polluta nts. Itis
illeg alto dispose ofthem withth ehousehold
ru bbish. #
Dispose
ofbatt eries inan
en vironmen tally re sponsible manner.
Ta ke disc hargedbatt eries toaqu alif ied
spec ialistwo rkshop ortoacol lection
poin tfo rused batteries. Re
quirement s:
R Youre qu ire aCR 203 23V cell battery.
Mer cedes-Ben zre comme ndsthat youha ve the
batt eryre placed ataqu alif ied spec ialistwo rk‐
shop. 66
Opening andclosing

#
Remo vetheemer gency key(/ pag e66 ). #
Press release knob 2 down fullyand slide
co ver1 inthedir ect ion ofthear row . #
Foldout cover1 inthedir ect ion ofthe
ar row and remo ve. #
Remo vebatt erycom partmen t3 and take
out thedisc hargedbatt ery. #
Inser tth ene wbatt eryint obatt erycom part‐
ment 3.Obser vethepositiv epole marking
in thebatt erycom partmen tand onthebat‐
te ry when doingth is. #
Push inbatt erycom partment 3. #
Re-att achco ver1 and push ituntil it
eng ages. Pr
obl ems with theSm artK ey ,tr oub lesho ot‐
ing Yo
ucan nolon gerlo ck orunloc kth eve hicl e
Po ssible causes:
R The Smar tKey batt eryis we ak ordisc harged.
R The Smar tKey isfaulty . #
Chec kth ebatt eryusing theindicat orlam p
(/ page64 ). #
Replace theSmar tKey batt ery, ifnec essar y
(/ page66). #
Use theemer gency keyto loc kor unloc k
(/ page70). #
Have theSmar tKey checkedat aqu alif ied
spec ialistwo rkshop. Ther
eis int erfere nce from apo we rful radio
sig nal source
The Smar tKey function isim pai redby ,fo rex am‐
ple:
R Highvo ltag epo we rlines
R Mobi lephones
R Electr onicdevices (notebook s,table ts)
R Shielding duetome talobje ctsor induc tion
loops forelectr icalgate systems oraut o‐
matic barrier s #
Mak esur eth at ther eis suf ficie ntdist anc e
be tween theSmar tKey and thepo tentia l
sou rceof interfere nce.
Yo uha ve los ta Sma rtKe y #
Have theSmar tKey deactiv ated ataqu alif ied
spec ialistwo rkshop. #
Ifnecessar y,ha ve themec hanical lock
re placed aswell. Open
ingand closing 67

Door
s Un
loc king/opening thedoor sfrom theinsid e #
Tounlo ckand open afront door :pul ldoor
handl e2.
Loc king pin1pops upwhe nth edoor is
unloc ked. #
Tounlo ckare ar door :pul lth ere ar door
han dle.
The lockin gpin pops upwhen there ar door
is unlo cked. #
Toopen are ar door :pul lth ere ar door han‐
dle again. Cent
rally loc king andunloc kingtheve hicl e
fr om theinsid e #
Tounlo ck:pr ess button 1. #
Toloc k:press butt on2.
This does notloc kor unloc kth efuel filler flap.
The vehicle isno tunloc ked:
R Ifyo uha ve loc kedth eve hicle using the
Smar tKey .
R Ifyo uha ve loc kedth eve hicle using KEY‐
LESS -GO. Loc
king/unloc kingtheve hicl ewith KEY‐
LES S-GO Re
quirement s:
R The Smar tKey isouts idetheve hicle.
R The distance betwee nth eSmar tKey and the
ve hicle does notex ceed 3ft (1 m).
R The driver's door andthedoor atwhic hth e
door handle isused areclosed. 68
Openin gand closin g