check engine MERCEDES-BENZ CLA 2021 Owners Manual

#
Toswitc hon thepo we rsupp ly:pr ess but‐
to n1 once .
Yo ucan activat eth ewindshield wipers,for
ex am ple.
The powe rsupp lyis switc hedoffag ain ifth efo l‐
lo wing condition sar eme t:
R Youopen thedr iver's door .
R Youpr ess button1 twice mor e. #
Toswitc hon theignit ion:press butt on1
twic e.
The indic ator lam psintheins trument cluster
light up.
The ignit ionisswitc hedoffag ain ifone ofthe
fo llo wing condition sis me t:
R Vehicl eswith automatic transmiss ion:
Yo udo notst ar tth eve hicle within
15 minut esand thetransmission isin posi‐
tion 005Dortheelectr icpar king brak eis
applied.
R Youpr ess button1 once . St
arting theve hicl e St
arting theve hicl ewith thest ar t/s topbut‐
to n &
DANG ER Risk ofdeat hcause dby
ex haus tga ses
Combus tionengines emitpoisonous exhaus t
ga ses suchas carbon monoxide.Inhaling
th ese exhaus tga ses ishazar dous tohealt h
and leads topoisonin g. #
Neverlea vetheengine or,if pr esent ,
th eauxiliar yheating running inan
encl osedspa cewithout sufficie ntventi‐
la tio n. &
WARNIN GRisk offire due toflammab le
mat erial intheengine compartmen tor
th eex haus tsy stem
Flammable materials mayignit e. #
Ther efor e, checkre gular lythat ther e
ar eno flammab lemat erials inthe
engine compartmen tor on theex haus t
sy stem. Re
quirement s:
R The Smar tKey isin theve hicle andisrecog‐
nized . #
Shif tth etra nsmiss iontoposition 005Dor005C. #
Depr essthebr ak epedal andpress butt on
1 onc e. #
Ifth eve hicle does notst ar t:switc hof fnon-
essential consumer sand press butt on1
once. 12
8
Driving and parking

#
Ifth eve hicle still does notst ar tand the
Place theKey inthe Marked SpaceSee
Operator's Manualdisplaymessag ealso
appear sin themultifunc tiondispla y:star t
th eve hicle withth eSmar tKey inthemar ked
space (emergency operati on mod e)
(/ page 129).
% Youcan switchoffth eengine whiledriving
by pressing button1 forabo utthre esec‐
onds orby pressing button1 thre etimes
wit hin thre esecon ds.Besureto obser vethe
saf etyno tesunder "Driving tips"
(/ page13 1).
St arting theve hicl ewith theSm artK ey inthe
ma rked spa ce(emer gency oper ation mode)
If th eve hicle does notst ar tand thePlace the
Key inthe Marked SpaceSeeOperator 'sManual
messag eappear sin themultifunc tiondispla y,
yo ucan star tth eve hicle inemer gency operati on
mod e. Ma
rked space (exa mp lewit hcup holder without
co ver) #
Open theco verof mar kedspace 2ifnec es‐
sar y. #
Mak esur eth at mar kedspace 2isem pty. #
Remo veSmar tKey 1 from theke yring. #
Place Sma rtKe y1 inmar kedspace 2on
th esymbol 3.
The vehicle willstar taf te ra shor ttime.
If yo ure mo veSmar tKey 1 from mar ked
space 2theengine continues running .Fo r
fur ther engine star ts howe ver,Smar tKey 1
mus tbe locat edinmar kedspace 2onsym‐
bol 3during theent ire jour ney. #
Have Smar tKey 1 checkedat aqu alif ied
spec ialistwo rkshop.
If th eve hicl edoes notst ar t: #
Place SmartKey 1 inmar kedspace 2and
lea veitth er e. #
Depr essthebr ak epedal andstar tth eve hi‐
cle using thest ar t/ stop butt on.
% Youcan also switchon thepo we rsupp lyor
th eignition withth est ar t/ stop butt on. Dr
iving andparking 12
9

Pa
rk position 005Diseng aged aut omatic allyif one
of thefo llo wing condition sis me t:
R Youswit choffth eignition whentheve hicle
is statio naryand thetransmission positionis
005B or005E.
R Youopen thedr iver's door when theve hicle
is at ast ands tillor when drivin gat ave ry low
speed andthetransmission positionis005B or
005E.
% Tomaneu verwit han open driver's door ,
open thedr iver's door while atast ands till
and engagetrans miss ionposit ion005Bor005E
ag ain.
% Atvery low outs idetemp eratur esbelo w
appr ox.-4°F (-20° C),yo uma yno tbe able to
shif tth etransmission from 005Dtoano ther
tra nsmiss ionposition whentheengine is
switc hedoff.Ifth is isthecase, onlych ang e
th etransmission positionwhiletheengine is
ru nning . En
gaging drive position D #
Depr essthebr ak epedal andpush the
DIR ECT SELEC Tleve rdo wn pas tth efirs t
point ofresis tance.
Whe nth eaut omatic transmiss ionisin transmis‐
sion position 005B,itshif tsthege arsaut omat i‐
call y.This depends, amongother things ,on the
fo llo wing fact or s:
R The select eddrive pr ogr am
R The position oftheaccelera torpeda l
R The driving speed Pr
obl ems with thetransm ission Th
etransm ission hasafa ulty gear shif t
Po ssible cause:
R The transmission islosing oil. #
Have thetra nsmiss ioncheckedat aqu alif ied
spec ialistwo rkshop immediat ely. The
accel eration charact eristics getwo rse,
and thetransm ission nolong ershif ts.
Po ssible cause:
R The transmission isin emer gency operati on
mod e. #
Pullove rand stop theve hicle safely assoon
as possible, paying attention toroad and traf‐
fi c condi tions. #
Shif tth etra nsmiss iontoposition 005D. #
Switc hof fth eengine. #
Waitat leas tte nseco nds. #
Tryto star tth eengine again. #
Shif tth etra nsmiss iontoposition 005B. #
Have thetra nsmiss ioncheckedat aqu alif ied
spec ialistwo rkshop immediat ely. Dr
iving andparking 14
1

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(/ page25 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 care255

#
Drain of fan 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. #
Consult 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. 258
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 (/ page25 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. Maint
enance andcare259

Chec
kingthebr ak epa dth ickness #
Bring theve hicle andwheels intoasuit able
position sothat youcan positionth ega ug e.
% The positionto place gaug e3 depen dson
th eeq uipment. Dependingonthebr ak ecali‐
per used, correct poi nt3 iseith er inthe
middl eor attheside ontheupper endofthe
br ak epad. #
Switc hof fth eengine. #
Secur eth eve hicle agains tro lling away. #
Take thega ug eout oftheve hicle document
wa lletin theglove box. #
Place thega ug ebe tween thewheel's spokes
in position 3onthebr ak epad. #
Hold thega ug eve rticall yto thebr ak edisc
and slide measur ingpin 2ontobr ak edisc
1. #
Chec kwhic hcolor field 4thear row on
measur ingpin ispointing to.
Gr een :th ebr ak epad thickn ess issuf ficie nt.
Re d:thebr ak epad thickn ess isno tsuf ficie nt.
Ha ve thebr ak epads checkedat aqu alif ied
spec ialistwo rkshop.
% Toavo idan inac cura temeasu rement :
R Mak esur eth ewheels aresuit ablyposi‐
tion ed.
R Inthecase ofper fora tedbr ak ediscs, do
no tput themeasur ingpin onone ofthe
bor esinthebr ak edisc. Cleaning
andcare 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 Maint
enanceand care26
1

&
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 27
9

Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions #
Close thetrunk lid.
00B2
Check Washer Fluid *T
hewasher fluid leve lin thewa sher fluid reser voirhas dropped belowtheminimum. #
Addwa sher fluid (/ page26 0). Engine
Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions
To switch engine off,press
and hold Start/S topbut-
ton foratleast 3secon ds
or press 3times. *Y
ouhave pressed thest ar t/ stop butt onwhile theve hicle isin mo tion. #
Information aboutswitchingoffth eengine whiledriving (/page12 8).
00BD
Che ckCoo lant Level See
Opera tor'sManu al *T
hecoolant leve lis toolow.
* NO
TEEngi nedama gedue toinsuf ficie ntcool ant #
Avoid long journeys wit hins ufficie ntcool ant. #
Addcoolant (/page259 ). 34
6
Dis play messa gesand warning/ indic ator lam ps

Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions #
Have theengine cooling system checkedat aqu alif ied spec ialistwo rkshop.
ÿ
Coola ntToo HotStop Vehi-
cle Turn Engine Off *T
hecoolant istooho t. #
Pull overand stop theve hicle safely and switc hof fth eengine, paying attent ion toroad and traffic condi tions. &
WARNIN GDang erofburnswhen opening thehood
If yo uopen thehood when theengine hasoverheat edordur ing afire intheengine compartmen t,yo uco uld
co me intoco ntact withho tga ses orother escaping operating fluids. #
Beforeopen ingthehood, allowtheengine tocool down. #
Intheeve ntofafire intheengine compartmen t,ke ep thehood closed andcallthefire ser vice. #
Waitunt ilth eengine hascooled down. #
Mak esur eth at theair supply tothera diat orisno tobs truct ed. #
Avoiding highloads ontheengine, drive to thenear estqu alif ied spec ialistwo rkshop. Indoing so,ensur eth at
th ecoolant temp eratur edispla yre mains belowthere dmar king.
ÿ *T
hefanmo toris faulty . #
Avoiding highloads ontheengine, drive to thenear estqu alif ied spec ialistwo rkshop. Indoing so,ensur eth at
th ecoolant temp eratur edispla yre mains belowthere dmar king. Displa
ymessag esand warning/ indic ator lam ps 34
7