service MERCEDES-BENZ A-CLASS SEDAN 2021 Owner's Guide

R
Ther eis amalfunct ioncaused byano ther
ra dio signal source
Chec kingthetir epr essur ewit hth etir epr es‐
sur emoni toring system
Re quirement s:
R The ignit ionisswitc hedon.
On- boar dcom puter:
4 Service 5
Tires
One ofthefo llo wing displa ysappear s:
R Cur rent tirepr ess ureand tirete mp eratur eof
th eindividual wheels: R
Tire pressure willbedisplayed afterdriving a
few minutes
R Tire Pressure MonitorAct ive: thete ac h-in
pr oce ssofthesy stem isno tye tcomple te.
The tirepr essur esarealr eady being moni‐
to re d. #
Com pareth etir epr essur ewit hth ere com‐
mend edtirepr ess urefo rth ecur rent operat‐
ing cond ition (/ page 290). Observeth e
no teson tirete mp eratur e(/ page288).
% The values displa yedin theon- boar dcom‐
put erma yde viat efrom those ofthetir e
pr essur ega ug eas they referto sea leve l.At
high elevatio ns, thetir epr essur eva lue indi‐
cat edbyapr essur ega ug ear ehigh erthan
th ose shownbytheon- boar dcom puter.In
th is case, donotre duce thetir epr essur e.
Re star ting thetir epr essur emoni toring sys‐
te m
Re quirement s:
R The recomme ndedtirepr ess ureis cor rectl y
se tfo rth ere spectiv eoper ating status onall
of thewheels (/page288). Re
star tth etir epr essur emonit oring system in
th efo llo wing situat ions:
R The tirepr essur ehas chang ed.
R The wheels ortires have been chang edor
ne wlyins talled.
On- boar dcom puter:
4 Service 5
Tires #
Swipe down wardson Touc hCon trol on the
lef t-hand sideofthesteer ing wheel.
The Use Current Pressures asNew Refer-
ence Values messag eis sho wninthemulti‐
func tion displa y. #
Torestar t,pr ess Touc hCon trol on thelef t-
hand sideofthesteer ing wheel.
The Tire Press. MonitorRestart edmessag eis
sho wninthemultifunc tiondispla y.
Cur rent wa rning mess ages aredele tedand
th eye llo w0077 warning lam pgoes out.
Af teryo uha ve been driving fora fe w
minut es,thesy stem checks whe ther thecur‐
re nt tirepr ess ures arewi thin thespecif ied
ra ng e. The current tirepr ess ures areth en
accep tedas refere nce values andmon itor ed. Wheels
andtires 293

Be
sureto also payatt ent ion tothefo llo wing
re lat ed topic:
R Noteson tirepr essur e(/ page288) Ti
re pres sur elo ss wa rning system Fu
nction ofthetir epr essur eloss warning
sy stem
The tirepr essur eloss warning system warnsth e
dr iver by means ofdisp lay messa geswhen ther e
is ase vere tirepr es su re loss.
Sy stem limit s
The system maybe impair edorma yno tfunc tion
par ticular lyin thefo llo wing situat ions:
R Incorrectly settir epr ess ure
R Sud den press urelos scau sed,fo rex am ple,
by afo re ign obje ctpene tratin gth etir e
R Steady pressur eloss inseveraltir es
The system has are strict ed ordel aye dfunc tion
par ticular lyin thefo llo wing situat ions:
R Poor ground condit ions,e.g.snowor gra vel
R Driving with sno wch ains R
When adoptingave ry spor tydriving style
wit hhigh corner ing speeds orsudden accel‐
er ation
R Drivin gwit hahigh load
The tirepr essur eloss warning system isonl yan
aid. Itis thedr iver's responsibili tyto setth etir e
pr essur eto there comme ndedcoldtirepr ess ure
su itab leforth eoper ating situation andtocheck
it.
Be sureto also obse rveth efo llo wing further
re lat ed subje cts:
R Noteson tirepr essur e(/ page288)
R Displa ymessag esabout thetir es
(/ page37 2)
Re star ting thetir epr essur eloss warning
sy stem
Re quirement s:
R The recomme ndedtirepr ess ureis cor rectl y
se tfo rth ere spectiv eoper ating status onall
wheels . Re
star tth etir epr essur eloss warning system in
th efo llo wing situat ions:
R The tirepr essur ehas chang ed.
R The wheels ortires have been chang edor
ne wlyins talled.
On- boar dcom puter:
4 Service 5
Tires #
Swipe down wardson Touc hCon trol on the
lef t-hand sideofthesteer ing wheel.
The Tire Pressure ControlSystem Active
Restart messageis sho wninthemultifunc ‐
tion displa y. #
Tobegin restar t,pr ess Touc hCon trol on the
lef t-hand sideofthesteer ing wheel.
The Tire Pressure NowOK?messag eis
sho wninthemultifunc tiondispla y. #
Select Yes. #
Toconf irm restar t,pr ess Touc hCon trol on
th elef t-hand sideofthesteer ing wheel.
The Run FlatIndic atorRestart edmessag eis
sho wninthemultifunc tiondispla y. 29
4
Wheels andtires

*
NO
TEBlocked spr aynozzl escau sed by
mixing windshieldwa sher fluids #
Donotmix MBSum merFitand MBWin‐
te rFit withot her windshield washer flu‐
ids. Do
notuse distilled orde- ionizedwa ter.Ot her‐
wise, thefill le ve lsen sor maybe trigg ered erro ‐
neou sly.
Re comme ndedwindsh ield wa sher fluid:
R Abo vefreezing point:e.g. MBSummerFi t
R Belo wfreezing point:e.g. MBWinterFi t
Fo rth ecor rect mixi ngratio ,re ferto theinf orma‐
tion ontheantif reeze container .
Mix washer fluid withwind shieldwa sher fluid all
ye ar round . Re
frig er ant No
teson refrig er ant
Obser vetheno teson oper ating fluids
(/ page32 3). *
NO
TEDama gedue toinc orrect refrig er‐
ant If
anon-appr ovedre frig er ant isuse d,thecli‐
mat econ trol system maybe damag ed. #
USA/China: UseonlyR‑1 34a refrig er‐
ant. #
Canada: UseonlyR‑1 234yf refrig er ant. *
NO
TEDama getotheclimat econ trol
sy stem due toinc orrect refrig er ant com‐
pr essor oil #
Onlyuse refrig er ant com pressor oilthat
has been approvedby Mer cedes-Ben z. #
Donotmix theappr ovedre frig er ant
com pressor oilwithadif fere nt refrig er‐
ant com pressor oil. Wo
rkon theclimat econ trol system maybe car‐
ri ed out onlyby aqu alif ied spec ialistwo rkshop.
All appli cable regulations, aswellas SAEstand‐
ar dJ63 9,mus tbe adher edto.
The information labelforth eclimat econ trol sys‐
te m rega rding there frig er ant type andthere frig‐ er
ant com pressor oil(PAG oil) islocat edon the
insid eof thehood. Inf
ormation label(exa mp le–US A/China)
1 Hazardand service warning symbols
2 Refrig er ant filling capac ity
3 Applic ablestandar ds
4 PAGoil par tnum ber
5 GWP(global warming potentia l)of there frig‐
er ant used
6 Refrig er ant type Te
ch nica lda ta 329

Inf
ormation label(exa mp le–Canada)
1 Hazardand service warning symbols
2 Refrig er ant filling capac ity
3 Applic ablestandar ds
4 PAGoil par tnum ber
5 GWP(global warming potentia l)of there frig‐
er ant used
6 Refrig er ant type
Symbo ls1 indica tethefo llo wing:
R Possible dangers
R The need tohave ser vice workcar ried out at
a qu alif ied spec ialistwo rkshop only Fi
lling capacityforre frig er ant and PAGoil Model
Refrig er ant
All model s2 4.3±0.4 oz
(690 ±10 g) Model
PAGoil
All model s2 .8±0.4 oz
(80 ±10 g) Ve
hicl edata Ve
hicl edimens ions The
heightsspeci fied mayva ry as are sult ofthe
fo llo wing fact or s:
R Tire s
R Load
R Conditio nof thesuspension
R Option aleq uipment 330
Tech nica lda ta

Disp
laymes sages Int
roducti on In
fo rm ation about displaymessag es
Displ aymessa gesappea ron themultifunc tion
displa y.
Dis play messa geswit hgr aphical symbols are
sim plified intheOper ator's Manual andmaydif‐
fe rfr om thesymbols onthemultifunc tiondis‐
pla y.The multifunct iondispla ysho wshigh-pr ior‐
ity displa ymessag esinred. Cer tain displa ymes‐
sag esareacc ompanied byawa rning tone.
Pl ea se act inacco rdanc ewit hth edispla ymes‐
sag esand follo wtheadditional notesin the
Oper ator's Manual .
Fo rsome display messa ges,asymbol willalso
be sho wn:
R Õ Further information
R 00A4 Hidedispla ymessag e
Wi th thelef t-hand Touc hCon trol, youcan select
th ere spectiv esymbol byswiping tothelef tor
ri ght. Press theÕ symbol tosho wfur ther infor‐ mation
onthemedia display.Press the00A4
symbol tohide thedispla ymessag e.
Yo ucan hide low- prior ity displa ymessag esby
pr essing theP backbutt onorthelef t-hand
To uc hCon trol. The displ aymessa geswill then
be stor ed inthemessag ememor y.
Re ctify thecause ofadispla ymessag eas
qu ickl yas possible .
High- prior ity displa ymess ages can notbe hid‐
den. Themultif unction displa ysho wsthese dis‐
pla ymessag escon tinuousl yuntil thecause of
th edispla ymessag ehas been rectif ied.
Cal ling up save ddispl aymes sages
On-b oard com puter:
4 Service5
1Mes sage
If th er ear eno displa ymessag es,NoMessages
will appear onthemultifunc tiondispla y. #
Scrollth ro ugh thedispla ymessag esby swip‐
ing upw ards ordown wardson thelef t-hand
To uc hCon trol. #
Toexitth emess agemem ory: press the
bac kbutt onP. 332
Displa ymessag esand warning/ indic ator lam ps

Occupant
safety Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions
0075 SRS Malfunct ionServic e
Required *T
herestra int system ismalfunct ioning(/page37 ). &
WARNIN GRisk ofinju rydue tomalfu nctions inthere stra int system
Com ponen tsinthere stra int system maybe activ ated unint entionally ornotdeplo yas planned inan acciden t. #
Have there stra int system checkedand repair edimmediat elyataqu alif ied spec ialistwo rkshop. 0075
Front LeftMalfunction
Service Required(exa mp le) *T
hecor responding restra int system ismalfunct ioning(/page37 ). &
WARNIN GRisk ofinju rydue tomalfu nctions inthere stra int system
Com ponen tsinthere stra int system maybe activ ated unint entionally ornotdeplo yas planned inan acciden t. #
Have there stra int system checkedand repair edimmediat elyataqu alif ied spec ialistwo rkshop. 0075
Left Side Curtain Airbag
Malfunction Service
Requ ired(exa mp le) *T
hecor responding windowcur tain airbag ismalfun ctionin g(/ page37 ). &
WARNIN GRisk ofinju ryor fata linj urydue toamalf unctionin thewindo wcur tain airbag
The windo wcur tain airbag mightbetrigg ered unin tentio nallyor might notbe trigg ered atall intheev ent ofan
acciden t. #
Have thewindo wcur tain airbag checkedand repair edimmediat elyat aqu alif ied spec ialistwo rkshop. Displa
ymessag esand warning/ indic ator lam ps 333

Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions
Servic eRequired DoNot
Shift Gears VisitDealer *T
hetransmission ismalfunctionin g.The transmission positioncannolong erbe chang ed. #
When transm issionposit ion005Bisselec ted, con sult aqu alif ied spec ialistwo rkshop anddonotch ang eth etra ns‐
mission position. #
Forall other transmission positions,parkth eve hicle safely. #
Consult aqu alif ied spec ialistwo rkshop orbreakdo wnservice.
Reversing NotPossible
Service Required *
The transmission ismalfunctioning. Thetransmission position005Ecanno tbe select ed. #
Consult aqu alif ied spec ialistwo rkshop.
Transmission Malfunction
Stop *
The transmission ismalfunctioning. Thetransmission shiftsto neu tral 005C automatical ly. #
Stop theve hicle immediat elyinaccor dance withth etraf fic condi tions. #
Depr essthebr ak epedal. #
Engage par kposition 005D. #
Consult aqu alif ied spec ialistwo rkshop.
Transmission Malfunction *T
hetransmission ismalfunctionin g.The cause couldbeanove rheat edclutc hor bloc kedge ars. #
Letth etransmission cooldown. #
Ifth edispla ymessag est ill appear sfo llo wing are star t,con sult aqu alif ied spec ialistwo rkshop. 34
8
Dis play messa gesand warning/ indic ator lam ps

Ac
tiveEmerg encyStop Assis t.............1 70
Ac tiveLa ne Chang eAssi st<0011001100110011001100110011001100110011001100110011001100110011
001100110011> 171
Fu nctio n<0011001100110011001100110011001100110011001100110011001100110011
001100110011001100110011001100110011> <0011001100110011001100110011001100110011001100110011001100110011
00110011001100110011>168
Sy stem limits ....................................... 168
Ad aptiv ecr uise contr ol
see ActiveDis tance AssistDIS TRONI C
Ad aptiv eHighb eamAssist
Fu nctio n<0011001100110011001100110011001100110011001100110011001100110011
001100110011001100110011001100110011> <0011001100110011001100110011001100110011001100110011001100110011
001100110011001100110011>112
Swi tching on/of f<0011001100110011001100110011001100110011001100110011001100110011
0011001100110011001100110011001100110011001100110011001100110011
00110011> 113
Ad diti ves.................................................. 326
En gine oil............................................ 326
Fu el ..................................................... 326
Ad diti ves(engine oil)
see Additiv es
Ad diti ves(fuel)
see Fuel
Af ter-sales service center
see ASSYSTPL US
Air bag
Re duced protect ion ...............................4 4
Air cond itioning menu
Callin gup ............................................ 122 Air
distribut ion
Se tting (MB UXmult imed iasystem) ..... 122
Air inle t
see Air-water duct
Air pressu re
see Tire pressur e
Air vents ................................................... 123
Ad jus ting (front) ............. .....................123
Ad jus ting (rea r) ............. .......................124
Air vents
see Airvents
Ai r-re cir cula tion mode............................ 123
Air -water duct .......................................... 256
Ke eping free ........................................2 56
Airb ag....... ..................................................42
Ac tivati on ........... ...................................37
Fr ont airbag (driver ,fr ont passeng er)....4 2
Ins tallation locations .............................4 2
Knee airbag........................................... 42
Ov ervie w ..... ................................... ....... 42
PA SSENGER AIRBAGind icat orlam p.....4 7
Pr otect ion ....................................... .......4 3
Sid eairba g<0011001100110011001100110011001100110011001100110011001100110011
0011001100110011001100110011001100110011001100110011001100110011
001100110011001100110011001100110011001100110011> 42Wi
ndo wcur tain airbag ...........................4 2
Alar m
see Panic alar m
Al ar m system
see ATA(anti-t heftal ar m system)
All-wheel drive
see 4MA TIC
Ambient lighting
Se tting (multimedia system) ................1 14
Andr oidAuto
see Smar tphone integr ation
Animals Pets intheve hicle ................................. 65
Anti-loc kbr aking system
see ABS(An ti-loc kBr akin gSy stem)
Anti-skid chains
see Snowch ains
Anti -thef tpr otection
Imm obiliz er............................................ 84
Ant icip ator yoccup antprotection
see PRE- SAFE®
(anticip ator yoccu‐
pa nt protect ion) Inde
x395

Data
storage
Dat apr otect ion rights ..................... ...... 33
Elect ronic contr oluni ts <0011001100110011001100110011001100110011001100110011001100110011
001100110011001100110011001100110011> 30
Onl ine service s<0011001100110011001100110011001100110011001100110011001100110011
001100110011001100110011001100110011> .............33
Ve hicle ............................................. ..... 30
Deactiv atingthealarm(ATA ).................... 85
Dealer ship
see Qualif iedspec ialistwo rkshop
Dec laration ofconf ormity
Wi reless vehicle component s................2 6
Decor ative fo il(cleaning instructions) ..261
Def initions (tiresand loading )...............3 04
De stinat ionentr y.... ................................ 223
En tering aPOI oraddress <0011001100110011001100110011001100110011001100110011001100110011
0011001100110011> 223
De tectin ginat tentiv eness
see ATTENTION ASSIST
Diagnos ticsconnec tion............................2 7
Digita lOp erator' sMa nua l........................ 20
Dingh yto wing
see Tow- bar system
DIRECT SELECT leve r............ ...................137
Eng aging drive po sitio n............ ........... 139 Eng
aging neu tral ............. .....................138
Eng aging park position .................. ...... 138
Eng aging park position automatic ally .. 138
Eng aging reve rsege ar .................... .....1 38
Fu nctio n<0011001100110011001100110011001100110011001100110011001100110011
0011001100110011001100110011001100110011> <0011001100110011001100110011001100110011001100110011001100110011
0011001100110011>137
Disp lay(car e)...........................................2 63
Di spla y(MBUX multimedia system)
Hom escr een .......................................2 09
Di spla y(multime diasystem) .................. 210
Oper ating ............................................. 210
Disp lay(on- boardcom puter)
Dis play son themultifunc tiondispla y.. 205
Displa ymessag e.....................................3 32
Ca lling up (on-boa rdcom puter) ..... ......3 32
No tes .................................................. 332
Displa ymessag es
00B2 ---mp h...................................... 357
ç ---mp h...................................... 357
003D 12VBatt erySee Oper ator's
Manual ................................................ 370
: ActiveHea dlamps Inoperati ve .... 339 é
ATTENTION ASSISTInoper ative
... ..........................................................3 56
é ATTENTION ASSIST: Take a
Br ea k! <0011001100110011001100110011001100110011001100110011001100110011
00110011001100110011> <0011001100110011001100110011001100110011001100110011001100110011
00110011001100110011>........357
: Automatic HeadlampMode
Inoper ative..... ..................................... 338
û BeforeSt artin gth eEn gine,
Tu rn Steer ing Wheel ............................3 42
0027 CheckBrak eFlu idLevel.............3 55
0026 CheckBrak ePa ds See Oper a‐
to r's Manua l...... .................................. 356
00BD CheckCool antLevelSee Oper‐
at or's Manual ...................................... 344
00B3 CheckEn gine OilLevel(A dd 1
qu art) .................................................. 377
: CheckLef tLo wBeam (exa m‐
ple) ...................................................... 338
0077 CheckTire s ................................ 373
00B2 CheckWa sher Fluid ...................3 44 400
Index

ÿ
Coolan tTo oHo tSt op Vehicle
Tu rn Engi neOff............ ........................ 345
00CE Current lyUn available Camera
Vi ew Restrict ed <0011001100110011001100110011001100110011001100110011001100110011
0011001100110011001100110011001100110011001100110011> ......363
ç Current lyUn available Radar
Sen sorsDir ty ...................................... 362
0025 Currentl yUna vailable See
Opera tor's Manua l...... .........................365
00E5 Current lyUn available See
Operat or'sMan ual...............................3 66
Á Don't Forget Your Key................ 337
00B3 Engin eOil LevelCann otBe
Mea sured <0011001100110011001100110011001100110011001100110011001100110011
0011001100110011> <0011001100110011001100110011001100110011001100110011001100110011
0011001100110011>....378
00B3 EngineOilLe velLo wStop Vehi‐
cle Turn Engi neOff............ ..................377
00B3 EngineOilPr ess ureSt op
Switc hOf fEngin e................................ 378
00B3 EngineOilRe duce OilLevel........ 377
0075 Front LeftMalfunction Service
Re quired (exa mp le) .............................3 33 00D4
FuelLevelLo w ............................ 346
00D4 GasCap Loose ...........................3 46
0025 Inoper ativeSee Oper ator's
Manu al....... ......................................... 366
00E5 Inoper ativeSee Oper ator's
Manu al....... ......................................... 367
007A Inoper ativeSee Oper ator's
Manu al....... ......................................... 368
0053 Inoper ative....... .......................... 369
: Intell.Ligh tSy stem Inoperativ e
... ..........................................................3 39
Á KeyNo tDe tected (red displ ay
messa ge).............................................3 37
Á KeyNo tDe tected (whit edis‐
pl ay messa ge).....................................3 36
0075 LeftSide Curtain Airbag Mal‐
fun ction ServiceRe quired (exa mp le) ...3 33
ä Malfunction Drive at Max. 50
mp h..................................................... 364 :
Malfunction SeeOper ator ’s
Manual ................................................ 338
Á ObtainaNe wKe y.......................3 36
ç Off....... .......................................358
00D9 Off....... .......................................356
0049 Parking Brak eSee Opera tor's
Manua l...... ...........................................351
0077 PleaseCor rect Tire Pressur e...... 373
0049 Please Release Parking Brak e.... 354
Á Replace KeyBat tery <0011001100110011001100110011001100110011001100110011001100110011
001100110011> 336
003D SeeOperator's Manua l..... .......... 370
0075 SRSMalfunction Service
Re quired .............................................. 333
Ù Steer ing Malfunct ionIncreased
Ph ysical Effort See Operator's Man‐
ua l...... ................................................. 341
Ù Steer ing Malfunct ionSee Oper‐
at or's Manual ...................................... 342
Ù Steer ing Malfunct ionStop
Immediat elySee Oper ator's Manual ....3 41 Inde
x40
1