2020 MERCEDES-BENZ A-CLASS SEDAN ECU

Diag
nostics connect ion
The diagn ostics conn ection ison lyinte nde dfo r
th econ nect ionofdiagnos ticdevices ataqu ali‐
fi ed specialis two rkshop. &
WARNIN GRisk ofacci dent dueto con‐
necting device sto thediagnos ticscon‐
nect ion
If yo uco nn ect equipme nttoadiagn ostic s
con nectionin theve hicle, itma yaf fect the
oper ation ofvehicle systems.
As are sult, theoper ating safetyof theve hi‐
cle could beaffect ed. #
Onlyconnect theve hicle diagnos tics
conn ection todevices whichha ve been
te sted withre ga rd totheir use and are
con sider edsafe. &
WARNIN GRisk ofacci dent dueto
object sin thedr iver's foot we ll
Obj ectsin thedr iver's foot we llma yim pede
pedal trav el or bloc kadepr essed pedal. This
jeopar dizestheoper ating androad
saf etyof theve hicle. #
Stow allobj ect sin theve hicle secur ely
so that they canno tget intoth edr iver's
fo ot we ll. #
Alw aysins tallth efloor mats securely
and asprescr ibed inorder toensur e
th at ther eis alw ayssuf ficie ntroom for
th epedals. #
Donotuse loose floor mats anddonot
place floor mats ontopof one another. *
NO
TEBatt erydi sc ha rging from using
de vice sconne cted tothediagnos tics
con nect ion Using
devices atthediagnos ticsconnect ion
dr ains thebatt ery. #
Chec kth ech arge leve lof thebatt ery. #
Ifth ech arge leve lis low, charge the
batt ery, e.g. bydriving acon sider able
dis tance. Co
nnecti ngequip ment tothediagnos ticscon‐
nect ioncan lead toemissions monitoring infor‐
mation beingrese t,forex am ple. This maylead
to theve hicle failing tomee tth ere qu iremen tsof
th ene xt emissions inspectionduring themain
inspect ion. Qualif
iedspecialis two rkshop
An author ized Mercedes-B enzCent erisaqu ali‐
fi ed specialis two rkshop. Ithas theneces sary
special skills,tools and qualif icat ionsto cor‐
re ctly carryout thewo rkrequ ired on your vehi‐
cle. This particular lyapplies tosaf ety-re leva nt
wo rks.
Fo rth efo llo wing, alwaysha ve your vehicle
ch eckedat an aut hor ized Mercedes- BenzCen‐
te r:
R safety-re leva nt wo rks
R service andmaint enance work
R repair work
R modif ications aswellas installation sand
con versions
R workon electr oniccomponent s Gener
alno tes 27

Limit
edWa rranty
* NO
TEDama getotheve hicle arising
fr om violation ofthese oper ating instruc‐
tion s. Damag
eto theve hicle canarise from viola‐
tion ofthese oper ating instruction s.
This damag eis no tco veredeit her bythe
Mer cedes-Ben zim plied warrant yor by the
Ne w‑ orUsed- Vehicle Warrant y. #
Followtheins truction sin these oper at‐
ing instruction son proper operation of
yo ur vehicle aswellas on possible vehi‐
cle damag e. QR
code forre scue card
The QRcode issecur edinthefuel filler flap and
on theopposit eside ontheB-pillar .In theeve nt
of an acci dent, rescue services canusetheQR
code toquickl yfind theappr opriatere scue card
fo ryo ur vehicle. Thecurrent rescue cardcon‐
ta ins themos tim por tant informa tionab ou tyo ur ve
hicle inacom pact form ,e.g. thero utin gof the
electr iclines.
Fu rther information canbeobt ained athttps: //
www .mercedes-benz .de/qr-code. Data
storage Electr
oniccontr olunit s Ele
ctro nic contr oluni tsareins talled inyour vehi‐
cle. Some ofthese areneces saryfo rth esaf e
oper ation ofyour vehicle, whilesome assistyo u
when drivin g(dr iver assis tance systems). In
addition, your vehicle prov ides comfort and
ent ertainm ent func tions,whic har ealso made
possible byelectr oniccontrol units.
Elect ronic contr oluni tscont ain da ta memor ies
whi chcan temp orarily orper manent lystor e
te ch nica linf orma tionab ou tth eve hicle's operat‐
ing stat e, com ponent loads, maintenance
re qu iremen tsand tech nica leve nts orma lfunc‐
tio ns. In
gener al,th is inf ormatio ndocum entsth est at e
of acom ponent part,amodul e,asy stem orthe
sur round ingssuc has:
R Operatin gst atus ofsystem com ponen ts(e.g.
fi ll le ve ls, batt eryst atus ,tir epr essur e)
R Status messagescon cerningth eve hicle or
its individua lcom ponent s(e.g. number of
wheel revo lution s/speed, longitudin alacc el‐
er ation ,lat eral acc eler ation ,displa yof fas‐
te ned seatbe lts)
R Malfunctio nsorfaults inim por tant system
com ponen ts(e.g. lights, brak es)
R Information oneve nts lead ing tovehicle
damag e
R System react ionsin spec ialdrivin gsit uatio ns
(e. g.airbag deployment,int erve ntio nof sta‐
bilit ycon trol systems)
R Ambien tcon ditions (e.g.temp eratur e,rain
sen sor)
In addition toprov iding theactual control unit
func tion,th is dat aassis tsthemanuf acturerin
de tecting andrectify ingmal functi onsand opti‐
mizi ngvehicle functions. Themajority ofthis Gener
alno tes 29

Re
stra int system Pr
otection prov ided bythere stra int system The
restra int system includes thefo llo wing com‐
pone nts:
R Seat beltsystem
R Airbags
R Child restra int system
R Child seatsecur ingsystems
The restra int system can help preve nttheve hi‐
cle occupants from coming intocont actwith
par tsof theve hicle interior intheev ent ofan
acciden t.In theev ent ofan acciden t,th e
re stra int system can also reduce thefo rc es to
whic hth eve hicle occupants aresubject ed.
A seat beltcanonlypr ov ide thebes tle ve lof pro‐
te ction ifit is wo rncor rectl y.Dep endingonthe
de tected acci dent situation, Emerg encyTensi on‐
ing Device sand /or airba gssupp lement thepr o‐
te ction offere dby acor rectl ywo rnseat belt.
Emer gency Tensi oni ng Device sand /or airba gs
ar eno tde ploy ed ineve ryacc iden t. In
order forth ere stra int system toprov ide the
int ended leve lof protect ion, eachve hicle occu‐
pant mustobser vethefo llo wing informatio n:
R Fasten seat belts correctl y.
R Sitinan almos tup right seat position with
th eir bac kag ains tth eseat backres t.
R Sitwithth eir feet resting onthefloor ,if pos‐
sible.
R Alw ayssecur eper sons under 5ft (1.50 m)
ta llin an addition alrestra int system suitable
fo rMer cedes-Benz vehicles.
Ho wever,no system available toda ycan com‐
ple tely elim inat einj uries and fata lities ineve ry
acc iden tsit uatio n.Inpar ticular ,th eseat belt
and airbag gener ally do notpr otect agains t
objec tspene trating theve hicle from theoutside.
It is also notpossible tocom plet elyru le out the
ri sk ofinjur ycaused bytheairbag deploying. Re
duce dre stra int system protection &
WARNIN GRisk ofinju ryor deat hfrom
modif ications tothere stra int system
The restra int system can nolong erfunc tion
cor rectly afte ralt erations have been made.
The restra int system mayth en notpr otect
th eve hicle occupants asintended byfailing
in an acc ident ortrigg ering une xpec tedly ,fo r
ex am ple #
Neveralt er thepar tsof there stra int
sy stem. #
Neverta mp erwit hth ewir ing orany
electr oniccomponen tpar tsor their
sof tware. If
it is neces saryto modify theve hicle toacc om‐
modat eaper son withdisabil ities, con tact an
au thor ized Mercedes-B enzCent erforde tails.
US Aonl y:forde tails, con tact ourCu stomer
Assis tance Center on 1-800-F OR-MER Cedes
(1‑80 0‑367‑63 72). 34
Occupant safety

&
WARNIN GRisk ofinju ryor deat hdue to
inc orrectl yfa stened seatbelt
If th eseat beltisno two rncor rectly ,it can‐
no tper form itsintended protect ive func tion.
In addition, anincor rectly fastened seatbelt
can also cause injuries,forex am ple, inthe
ev ent ofan acciden tor when braking or
ch ang ingdirect ion sudden ly. #
Alw aysensur eth at all vehicle occu‐
pants have their seat belts fastened
cor rectl yand aresitti ngprope rly. Alw
aysobser vetheins truction sabout thecor‐
re ct driver's seatpos ition and adjus ting theseat
(/ page90).
In order forth ecor rectly wornseat belttopro‐
vide theint ended leve lof protect ion, eachve hi‐
cle occupant mustobser vethefo llo wing infor‐
matio n:
R The seat beltmustno tbe twis tedand must
fi t tig htly and snuglyacr oss thebody . R
The seat beltmustbe routed acr oss thecen‐
te rof theshoulder andaslow do wn across
th ehips aspossible.
R The shoulder sectionoftheseat beltshould
no tto uc hyo ur neck nor berouted und er
yo ur arm or behin dyo ur bac k.
R Avoid wearing bulk yclo thing, e.g. awint er
coat .
R Push thelap belt down asfaras possi ble
acr oss your hips andpulltight wit hth eshoul‐
der sect ionofthebelt. Neverro uteth elap
belt across your abdom en.
Pr egn ant women mustals ota ke par ticular
car ewit hth is.
R Neverro uteth eseat beltacross shar p,poin‐
te d, abr asiv eor fragile objec ts.
R Onlyone person should useeachseat beltat
an yone time. Neverall ow babies andchil‐
dr en totrave lsitt ing onthelap ofano ther
ve hicle occupant.
R Neversecur eobjects withaseat beltifth e
seat beltisalso being usedbyone ofthe
ve hicle's occupants. Alwaysobser vethe
ins truct ions forloa ding theve hicle when secur
ingobject s,lugg ageor loads
(/ page99).
Also ensur eth at no obj ect s,e.g .a cus hion ,
ar eeve rpla ced between aper son and the
seat.
The seat belts onthefo llo wing seats areeq uip‐
ped withaspec ialseatb eltretract or:
R Front passeng erseat
R Rear seat s
Ac tivateor deacti vate thespecial seatbelt
re tract or(/ page 55).
If ch ildr enaretrav eling intheve hicle, besur eto
obser vetheins truction sand safetyno teson
"Chi ldren intheve hicle" (/page50). Occupant
safety 37

Limita
tionsofthepr otection prov ided bythe
seat belt &
WARNIN GRisk ofinju ryor deat hdue to
inc orrect sea tpos ition
The seatbel tdoe sno tof ferth eint ended
le ve lof protect ion ifyo uha ve notmo vedth e
seat backres tto an almos tve rtical posit ion.
When brakin gor intheeve ntofan acci dent,
yo uco uld slide underne athth eseat beltand
sus tain abdomin alor nec kinj uries, forex am‐
ple. #
Adjus tth eseat proper lybef orebegin‐
ning your jour ne y. #
Alw aysensur eth at theseat backres tis
in an almos tve rtical posit ionand that
th eshoulder sectionofyour seat beltis
ro uted acr oss thecent erofyour sho ul‐
der . &
WARNIN GRisk ofinju ryor deat hwhen
additional restra int systems areno tused
fo rper sons withasmal lerbuild
Pe rsons under 5ft (1.50 m)tallcan notwe ar
th eseat beltcorrectly without asuit able
additional restra int system.
If th eseat beltisno two rncor rectly ,it can‐
no tper form itsintended protect ive func tion.
In addition, anincor rectly fastened seatbelt
can also cause injuries,forex am ple, inthe
ev ent ofan acciden tor when braking or
ch ang ingdirect ion sudden ly. #
Alw ayssecur eper sons under 5ft
(1 .50 m)tallin asuit able restra int sys‐
te m. &
WARNIN GRisk ofinju ryor deat hdue to
damag edormodif iedseat belts
Seat belts cannotprov ide protect ion inthe
fo llo wing situat ions:
R The seat beltisdamag ed,has been modi‐
fi ed, isex treme lydirty, bleac hedordyed R
The seat beltbuckleisdamag edor
ex treme lydir ty
R Modif ication sha ve been made tothe
Emerg encyTensi oni ng Device ,sea tbe lt
anc horageor sea tbe ltre tract or
Sea tbe lts ma ysu stain non-visi ble damag ein
an acc iden t,e.g .due toglass splin ters.
Modif iedordamag edseat belts could tear or
fa ilin theev ent ofan acciden t,forex am ple.
Modif iedEmerge ncy Tensi oni ng Device sma y
be deploy ed unint entionally ornotfunc tion
as intended. #
Nevermodify theseat belts, Emergency
Te nsi oni ng Device s,sea tbe ltanc ho‐
ra ge sor seat beltretract ors. #
Makesur eth at theseat belts areno t
damag ed,areno two rnand arecle an. #
Alw aysha ve theseat belts checked
immed iatelyaf te ran accide ntata
qu alif ied spec ialistwo rkshop. Onl
yuse seat belts that areappr ovedfo ryo ur
ve hicle byMer cedes-Ben z. 38
Occupant safety

passeng
erside maydeplo y.The airbag is
deplo yedre ga rdless ofwhe ther thefront
passeng erseat isoccupied. Pr
otection bytheair bags Dep
endingontheacciden tsituation ,an airbag
ma ysupplement thepr otect ion offere dby acor ‐
re ctly fastened seatbelt. &
WARNIN GRisk ofinju ryor deat hdue to
inc orrect sea tpos ition
If yo ude viat efrom thecor rect sea tpos ition,
th eairbag cannotper form itsintended pro‐
te ctiv efuncti onand deployme ntma yev en
cause further injur ies.
In order toavo idrisk s, eac hve hicle occupant
mus talw aysmak esur eof thefo llo wing:
R Fasten seat belts correctly .Pr egna nt
wo men mustta ke par ticular careto
ensur eth at thelap belt neverlie sacr oss
th eabdomen. R
Adoptth ecor rect sea tpos ition and keep
as faraw ay as poss iblefrom theairbags.
R Obser vethefo llo wing informatio n. #
Alw aysmak esur eth at ther ear eno
objec tsbetween theairbag andvehicle
occupant. To
avo idtherisk sre sulting from thedeplo yment
of an airbag, eachve hicle occupant must
obser vethefo llo wing informatio nin par ticular :
R Beforest ar tin gyo ur jour ne y,adjus tyo ur seat
co rrect ly;th edr iver's seat andfront
passeng erseat should bemo vedas farbac k
as possi ble.
When doingso,alwaysobser vetheinf orma‐
tion onthecor rect driver's seatpos ition
(/ page 90).
R Only holdthesteer ing wheel bythesteer ing
wheel rim. This allows theairbag tobe fully
deplo yed.
R Alw ayslean agains tth eseat backres twhen
th eve hicle isin mo tion. Donotlean forw ards
or agains tth edoor orside windo w.Youma y ot
her wise beinthedeplo yment area ofthe
airbag s.
R Alw ayske ep your feet on thefloor .Do not
put your feet on thecoc kpit, forex am ple.
Yo ur feet ma yot her wise beinthedeplo y‐
ment area oftheairbag.
R Ifch ildr enaretra veling intheve hicle,
obser vetheadditional notes(/ page50).
R Alw aysst ow and secureobj ect scor rectl y.
Objects intheve hicle interior maypr eve ntan
ai rba gfrom func tioning correctly .Eac hve hicle
occupant mustalw aysmak esur eof thefo llo w‐
ing inpar ticular :
R Ther ear eno people, animals orobje cts
be tween theve hicle occupants andanair‐
bag.
R Ther ear eno object sbe tween theseat, door
and door pillar (B-pillar).
R Ther ear eno har dobjec ts,e.g. coat hangers,
hanging onthegr ab handles orcoat hooks.
R Ther ear eno accessor ypar ts,suc has mobile
na vig ation devices, mobile phones orcup
holder s,att ached totheve hicle within the 42
Occupant safety

The
status ofthefront passeng erairbag isdis‐
pla yedaf te rth eself-t est:
R PASSENGER AIRBAGON light sup for
60 seconds ,sub sequently both indic ator
lam psareof f(P AS SENGER AIR BA GON and
OF F): thefront passeng erairbag isable to
deplo yin theev ent ofan acciden t.
R PASSENGER AIRBAGOF Flight sup con tinu‐
ousl y:thefront passeng erairbag isdisabled.
It will then notbe deplo yedin theeve ntofan
acci dent.
If th ePA SSENGER AIRBAGON indicat orlam pis
of f,on lythePA SSENGER AIRBAGOF Find icat or
lam psho wsthest atus ofthefront passeng er
airbag. ThePASSENGER AIRBAGOF Find icat or
lam pma ybe litcon tinuousl yor be off.
If th ePA SSENGER AIRBAGOF Find icat orlam p
and the0075 restra int system warning lam p
light upsimult aneousl y,thefront passeng erseat
ma yno tbe used. Alsointhis case, donotins tall
a ch ild restra int system onthefront passeng er
seat. Have aut omat icfron tpasse nger airbag
shut offch eckedand repair edimmediat elyata
qu alif ied spec ialistwo rkshop. St
atus displa y
If th efront passeng erseat isoccupied, ensure,
bo th bef oreand during thejour ney,that thest a‐
tus ofthefront passeng erairbag iscor rect for
th ecur rent situa tion.
Af terin st alli ng are ar wa rd-faci ng child
re stra int system onthefront passeng er
seat :PA SSENGER AIRBAGOF Fmus tbe litcon ‐
tin uousl y. &
WARNIN GRisk ofinju ryor deat hfrom
using are ar wa rd-faci ng child restra int
sy stem when thefront passeng erfront
airbag isenabled
If yo usec ureach ild inare ar wa rd-facin g
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 theeve ntofan acci dent.
The child could bestru ck bytheairbag.
Alw aysensur eth at thefront passeng erair‐
bag isdeactiv ated. The PASSENGER AIRBAG
OFF indicat orlam pmus tbe lit. NEVER
useare ar wa rd-faci ng child restra int
sy stem onaseat protect edbyan ENABLED
FR ONT AIRB AG infront ofit,DE ATHor SERI‐
OUS INJURYtotheCH ILD can occur . When
installing ach ild restra int system onthe
fr ont passeng ersea t,obse rveth eve hicle-spe‐
cif icinf ormation (/page60).
Depending onthech ild restra int system and the
st atur eof thech ild, thePA SSENGER AIRBAG
OFF indicat orlam pma ybe off.In this case, do
no tins tallth ere ar wa rd-faci ng child restra int
sy stem onthefront passeng erseat.
Ins tead, installth ere ar wa rd-faci ng child
re stra int system onasuit able rear seat .
Af terin st alli ng afo rw ard-f acin gch ild
re stra int system onthefront passeng er
seat :depen dingonthech ild restra int system
and thest atur eof thech ild, PASSENGER AIR
BA GOF Fma ybe litcon tinuousl yor be off.
Alw aysobser vethefo llo wing informatio n. 46
Occupant safety

#
Ifth eseat beltpre-t ension ingisno tre duced,
mo vetheseat backres tbac kslightl y.
The locking mechanism releases. Fu
nction ofPRE-S AFE®
PL US (anticipat ory
occupant protection plus) PRE-
SAFE®
PL US can detect cer tain im pact s,
par ticular lyan imm inentrear impact ,and take
pr e-em ptive measur estoprotect theve hicle
occupants. Thesemeasur escanno tnecessar ily
pr eve ntan imm inentimpact.
PR E-S AFE ®
PL US can implem entthefo llo wing
measur esindepe ndently of eac hot her :
R Tight ening theseat belts onthedr iver's seat
and front passeng erseat.
R Increasin gbr ak epr essur ewhen theve hicle
is statio nary.This brak eapplication iscan‐
celed automaticall ywhen theve hicle pulls
aw ay.
If an accident didnotoccur ,th epr e-em ptive
measur esthat we retake nar ere ve rsed. Sy
stem limit s
The system will notinitiat ean yaction inthefo l‐
lo wing situat ions:
R when backingup
The system will notinitiat ean ybr aking applica‐
tion inthefo llo wing situat ions:
R whils tdr ivin g
or
R when entering orexitin gapar kingspace
while using ActivePa rking Assist Saf
elytransp orting childr enintheve hicl e Alw
aysobser vewhen childr enaretrav eling
in theve hicl e %
Also strictly observe thesaf etyno tesfo rth e
specif icsituation. Inthis wa yyo ucan recog‐
nize potentia lri sk sand avoiddang ersif ch il‐
dr en aretrav eling intheve hicle
(/ page50). Be
dilig ent
Bear inmind that neg lectingto secur each ild in
th ech ild restra int system mayha ve ser ious con‐
seq uences. Alwaysbe dilig entinsecur ingach ild
car efull ybef oreeve ryjou rney .
To improve protect ion forch ildr enyoung erthan
12 yearsold orunde r5 ft (1.50 m)inheight ,
Mer cedes- Benzre comme ndsyouobse rveth e
fo llo wing informatio n:
R Alw ayssecur eth ech ild inach ild restra int
sy stem suitable forth is Mer cedes -Benz vehi‐
cle.
R The child restra int system mus tbe appr opri‐
at eto theag e, we ight andsize ofthech ild.
R The vehicle seatmustbe suit able forins tal‐
ling ach ild restra int system.
Ac cid ent statis ticssho wthat childr ensecur ed
on there ar seat sar ege ner ally saf erthan chil‐
dr en secur edon thefront seats. Forth is reason ,
Mer cedes-Ben zst ro ng lyadvis esthat youins tall
a ch ild restra int system onare ar seat . Oc
cupan tsaf ety 49