
IntelligentTechnology
Brakebooster
Thebrakeboosteramplifiesthepressureyouap-
plytothebrakepedal.
ZAWARNING
—Onlyapplythebrakesforthepurposeof
cleaningthebrakesystemwhenroadand
trafficconditionspermit.Youmustnoten-
danger
otherroadusersandincreasethe
riskofanaccident.
—Duetotheriskofinjury,onlyhave anau-
thorizedAudidealerorauthorizedAudi
ServiceFacilityworkonthebrakesystem.
Incorrectrepairscouldimpair thefunction.
—Neverletthevehiclerollwhiletheengineis
stoppedbecausethisincreasestheriskofan
accident.
@)Note
—Neverletthe brakes“rub”bypressingthe
pedallightlywhenbrakingisnotactually
necessary.Thiscauses thebrakestoover-
heatandincreasesbrakingdistanceand
causeswear.
—Beforedrivingdownhillalongdistanceona
steephill,decreaseyourspeedandselecta
lowergear.Thismakesuseoftheengine
brakingeffectandreducestheloadplaced
onthebrakes.Ifyouneedtobrakeaddition-
ally,brakeinintervalsandnotcontinuously.
@Tips
—Ifthebrakeboosterisnotworking,you
mustpressthebrake pedalwithmuchmore
forcethannormal.
—Ifyouretrofityourvehiclewithafrontspoil-
er,wheelcoversorsimilaritems,makesure
thattheairflowtothefrontwheelsisnot
obstructed.Otherwisethebrakesystemcan
overheat.
142
Electromechanical
steering,Dynamic
steering
Theelectromechanicalsteeringsupportsthe
driver'ssteeringmovements.
Powersteeringadaptselectronicallybasedon
thevehiclespeed.
Indicatorlightsandmessages
aSteering:malfunction!Pleasestopvehicle
Ifthisindicatorlightturnsonandstaysonand
thismessageappears,thepowersteeringmay
havefailed.
Stopthevehicleinasafelocationassoonaspos-
sible.Donotcontinuedriving.Seeanauthorized
AudidealerorauthorizedAudiServiceFacilityfor
assistance.
aSteering:malfunction!Youcancontinue
driving
Iftheindicatorlightturnsonandthismessage
appears,thesteeringwheelmaybemoredifficult
tomoveormoresensitivethanusual.Thesteer-
ingwheelmayalsobeturnedtothesidewhen
drivingstraight.
DriveslowlytoanauthorizedAudidealerorau-
thorizedAudiServiceFacilitytohavethe mal-
functioncorrected.
Dynamicsteering:correctingsteeringwheel
position
Iftheindicatorlightturnsonandthismessage
appears,thedynamicsteering”isreinitializing.
Thesteeringwheelwillbeeasytomoveafter
startingtheengine.Reinitializationmightbe
necessaryifthesteeringwheelwasmovedwhile
theenginewasswitchedoff.Thedisplayturnsoff
iftheinitializationwassuccessful.
(i)Tips
—Iftheaorlindicatorlightonlystayson
forashorttime,youmaycontinuedriving.
— Thedynamicsteeringstabilitysystems
=>page138arenotavailableintheeventof
asystemmalfunction.

CheckingandFilling
Fuelfillerdooremergencyrelease
Ifthecentrallockingsystemmalfunctions,the
fuelfillerdoorcanbe unlockedmanually.
Fig.251Rightsidetrimpanelintheluggagecompart-
ment:openingthetrimpanel
Fig.252Luggagecompartment:fuelfillerdooremergency
release
Theemergencyopeningmechanismislocated
behindtherightsidetrimpanelintheluggage
compartment.
>Openthecoverinthesidepanel>fig.251.
>Tounlockthefuelfillerdoor,loosen theloop
fromtheretainerandthenpullontheloop
carefully>fig.252>@.
>Pressontheleftsideofthefuelfillerdoorto
openit>page306,fig.249.
®Note
Onlypullontheloopuntilyoufeelresistance.
Youwillnothearitrelease.Ifyoucontinueto
pull,youcoulddamagetheemergencyre-
leasemechanism.
308
Catalyticconverter
Thevehiclemayonlybedrivenwithunleaded
gasoline,orthecatalyticconverterwillbede-
stroyed.
Neverdriveuntilthetankiscompletelyempty.
Theirregularsupplyoffuelthatresultsfromthat
cancauseenginemisfires.Uncombustedfuel
couldentertheexhaustsystem,whichcould
causeoverheatinganddamagetothecatalytic
converter.
ZAWARNING
Thetemperatureoftheexhaustsystemis
high,bothwhendrivingandafterstopping
the
engine.
—Nevertouchtheexhausttailpipesoncethey
havebecomehot. Thiscouldresultinburns.
—Donotparkyourvehicleoverflammable
materialssuchasgrassorleavesbecause
thehightemperatureoftheemissionssys-
temcouldstartafire.
—Donotapplyunderbodyprotectantinthe
exhaustsystemarea,becausethisincreases
theriskoffire.
OnBoardDiagnostic
System(OBD)
TheOnBoardDiagnosticSystemmonitorsthe
engineandtransmissioncomponentsthatinflu-
enceemissions.
Fig.253Footwellonleftside ofthevehicle:connection
portfortheOnBoardDiagnosticSystem(OBD)

CheckingandFilling
engine.Ifthishappens,onlyusewaterand
restorethecorrectmixtureratiowiththe
specifiedcoolantadditiveassoonaspossi-
ble.
—Onlyrefillwithnewcoolant.
—Radiatorsealantmustnot bemixedwith
thecoolant.
Addingcoolant
©=FeRAZ-0540
MIN
Fig.258Enginecompartment-coolantexpansiontank
(diagram):@coverwithreleasebutton;2)markings
Observethesafetyprecautions>page309,
Workingintheenginecompartment.
Checkingtheenginecoolantlevel
>Parkthevehicleonalevelsurface.
>Switchtheignitionoff.
>Readthecoolantlevelonthecoolantexpansion
tank>page311,fig.256.Thecoolantlevel
mustbebetweenthemarkings@)>fig.258
whentheengineiscold.Whentheengineis
warmitcanbeslightlyabovetheupper mark-
ing.
Addingcoolant
>Allowtheenginetocool.
> Placealarge,thicktowelonthecoolantexpan-
siontankcover.
>Pushthereleasebutton(@)9fig.258onthe
capandcarefullyturnittotheleftuntilyou
feelresistance>/\.
>Pushthereleasebuttonagainandremovethe
capcompletely.
>Makesurethatthefluidlevelremainsstable.
Add morecoolantifnecessary.
>
Turn thecaptotherighttotightenituntilyou
feelresistanceasecondtime.
316
Coolantlossusuallyindicatesthatthereisaleak.
Immediatelydriveyourvehicletoanauthorized
AudidealerorauthorizedAudiServiceFacility
andhavethecoolingsysteminspected.Ifthe
coolingsystemisnotleaking,coolantlosscanre-
sultfromthecoolantboilingdueoverheating
andthenbeingforcedoutofthecoolingsystem.
ZA\WARNING
— Theenginecompartmentinanyvehiclecan
beadangerousarea.Stoptheengineandal-
lowitto coolbeforeworkingintheengine
compartment.Alwaysfollowtheinforma-
tionfoundin>page309,Workinginthe
enginecompartment.
—Neveropenthehoodifyoucan seeorhear
steamorcoolantescapingfromtheengine
compartment.Thisincreasestheriskof
burns.Thecoolingsystemisunderpressure.
Whenyounolongerseeorhearsteamor
coolantescaping,youmayopentheengine
compartmentwithcaution.
—Whenworkingintheenginecompartment,
rememberthattheradiatorfancanswitch
oneveniftheignitionisswitchedoff,which
increasestheriskofinjury.
—Coolantadditiveandcoolantcan bedanger-
oustoyourhealth.Forthisreason, storethe
coolantintheoriginalcontainerandaway
fromchildren.Thereisariskofpoisoning.
@)Note
Donotaddcoolantiftheexpansiontankis
empty.Theremaybe airinthecoolingsys-
tem,whichincreasestheriskofenginedam-
age.Ifthisisthecase,donotcontinuedriv-
ing.SeeanauthorizedAudidealerorauthor-
izedAudiServiceFacilityforassistance.

CheckingandFilling
Ifthismessagedoesnotturnoff,driveimmedi-
atelytoanauthorizedAudidealerorauthorized
AudiServiceFacility.
ZA\WARNING
Whenthereisanelectricalsystemmalfunc-
tion,vehiclefunctionsmaynotworkanddriv-
ingstabilitymaybelimited,whichincreases
theriskofanaccident.Stopdrivingand
switchtheengineoff.SeeanauthorizedAudi
dealerorauthorizedAudiServiceFacilityfor
assistance.
Battery
Prlaameeeelec)
Becauseofthecomplexpowersupply,allworkon
batteriessuchasdisconnecting,replacing,etc.,
should only beperformedby anauthorizedAudi
dealerorauthorizedAudiServiceFacility>A\.
Multiplebatterieswithdifferenttechnologies
maybeinstalledinyourvehicle:
—Vehiclebattery(forexample,forstartingthe
engine,basicpowersupply)>page319,Lead
batteryor>page319,Otherbatterytypes
—Auxiliarybattery(forexample,forrecuperation
oroptionalequipment)>page319,Otherbat-
terytypes
Notrunningthevehicleforlongperiodsof
time
Thebatterywillgraduallydrainifthevehicle
doesnotrunforlongperiodsoftime.Toensure
thatthevehiclecanstillbestarted,theelectrical
equipmentwillbereducedorswitchedoff
=>page143.Someconveniencefunctions,such
asinteriorlightingorpowerseatadjustment,
maynotbeavailableundercertaincircumstan-
ces.Theseconveniencefunctionswillbeavailable
againonceyouswitchtheignitiononandstart
theengine.
Evenwhenelectricalequipmentisswitchedoff,
theequipmentcanstilldrainthebatteryifthe
vehicleisnotdrivenforlongperiodsoftime.
Deepdrainingresultsinachemicalreactionthat
destroys
theinsideofthebattery.Thebattery
318
mustbechargedeverymonthtopreventthis
=page319.Contact anauthorizedAudidealeror
authorizedAudiServiceFacilityformoreinfor-
mation.
Winteroperation
Coldweatherplaceshigherdemandsonthebat-
tery.Thisresultsinreducedstartingability.Have
thebatterycheckedbyanauthorizedAudidealer
orauthorizedAudiServiceFacilitybeforecold
weatherbegins.
Z\WARNING
—Allworkonthebatteryorelectricalsystem
inyourvehiclecanresultininjuries,chemi-
calburns,accidents,or burns.Becauseof
this,allworkmustbeperformedonlybyan
authorizedAudidealerorauthorizedAudi
ServiceFacility.
—Neverconnectthechargingcableorjump
startcabledirectlytoyourvehiclebattery.
Onlyusethe connectionsintheenginecom-
partment>page319.
ZAWARNING
CaliforniaProposition65Warning:
—Batteryposts,terminalsandrelatedacces-
soriescontainleadandleadcompounds,
chemicalsknowntotheStateofCalifornia
tocausecancerandreproductiveproblems.
Washhandsafterhandling.
()Note
—Ifthevehiclewillbe parkedforlongperiods
oftime,protectthebatteryagainstthecold
so thatitwillnot be destroyed by“freezing”
=page319,Chargingthebattery.
—Thereareelectricalcomponentsunderthe
cargofloorbehindatrimpanelthatwarm
upduringoperation.To reducetheriskof
thecomponentsoverheating, donotstore
objectssuchasblanketsunderthecargo
floor.Ifthecomponentsoverheat,theywill
switchofftemporarily.Thiswillbeindicated
byamessagethatwillbedisplayedinthe
instrumentclusteruntilthetemperaturere-
turnstonormal.
![AUDI S4 2019 Owners Manual Emergencyassistance
eeemacy
Appliesto:vehicleswithtiremobilitykit
[RAZ-0054]
Fig.269Diagram:tiremobilitykitconnection
Requirement:thetiremobilitykitmustbelaid
outandreadyforuse>page348 AUDI S4 2019 Owners Manual Emergencyassistance
eeemacy
Appliesto:vehicleswithtiremobilitykit
[RAZ-0054]
Fig.269Diagram:tiremobilitykitconnection
Requirement:thetiremobilitykitmustbelaid
outandreadyforuse>page348](/manual-img/6/57555/w960_57555-351.png)
Emergencyassistance
eeemacy
Appliesto:vehicleswithtiremobilitykit
[RAZ-0054]
Fig.269Diagram:tiremobilitykitconnection
Requirement:thetiremobilitykitmustbelaid
outandreadyforuse>page348.
Settingupthetiremobilitykit
>Openthecover@)onthecompressor)
>fig.268.
>Removetheconnector(4)andpressurehose(5)
withpressuregaugefromthehousing.
>Connectthecompressorpressurehose(5)to
theflange©onthetiresealantbottle@.
> Insertthesealantbottlewiththe flangeatthe
bottomintotheopening@)onthecompressor
cover.
>Removethevalvecapfromthefaultytire.
>Installthefillerhose@)onthevalve(7)
>fig.269.
>Connecttheplug@>fig.268toanoutletin
thevehicle.
>Switchtheignitionon.
D_Thecompressormaylookdifferent.However,thewayitis
operatedisgenerallythesame.
350
Inflatingatire
>Movetheswitch(8)>fig.269onthecompres-
sorintopositionI.
>Inflatethetiretobetween29psi(200kPA)
and36psi(250kPA)andreadthepressureon
thegauge.
>Ifthistirepressureisnotreached,removethe
fillerhose.Driveslowlyapproximately33feet
(10m)forwardorinreverseso thatthesealant
can bedistributedinthetire.Inflatethetire
again>A\.
Z\WARNING
—Readandfollowthemanufacturer'ssafety
precautionsonthecompressorandinthein-
structionsonthebottleofsealant.
—Ifatirepressureof29psi(200kPA)cannot
reachedafterinflatingfor6minutes,then
thetireistooseverelydamaged.Donotcon-
tinuedriving.
—Ifthetirecannotberepairedwiththetire
sealant,seeanauthorizedAudidealerorau-
thorizedAudiServiceFacilityforassistance.
(i)Tips
Donotoperatethecompressorformorethan
sixminutescontinuously,oritcanoverheat.
Oncethecompressorhascooled,youcancon-
tinuetouseit.
(eyaay)Clalare)
Appliesto:vehicleswithtiremobilitykit
>Affixthestickerthatsays"max.50mph(max.
80km/h)"thatisprovidedwiththetiremobili-
tykitwithinthedriver'sfieldofvision.
>Stopthevehicleafterdrivingforabout10mi-
nutesandcheckthetirepressure.
»Ifthetirepressureislowerthan19psi(130
kPA),thenthetireistooseverelydamaged.Do
notcontinuedriving.

Emergencyassistance
>Waitseveralhoursbeforeplacingthecollapsi-
blesparetireinthesparewheelwell.Only then
willitfolddowncompletelyso thatyoucan
storeitsecurely.
>Thenscrewthevalvecapbackontothevalve.
>Secure thecollapsiblesparetirewiththehand-
wheel.
> Foldthecargofloorcoverbackintoplace.
Snowchains
Usingsnowchainsonthecollapsiblesparetireis
notpermittedfortechnicalreasons.
Ifyouhavetodrivewithsnowchainsandafront
tirefails,mountthecollapsiblesparetireinplace
ofareartire.Installthesnowchainsontherear
tirethatyouremoved,andinstallthatinplaceof
thefronttirethatfailed.
ZA\WARNING
—Onlyusethecollapsiblesparetireinemer-
genciesanddriveverycarefully,especiallyif
it is
morethansixyearsold.
—Thecompressorandthehosecanbecome
veryhotduring operationwhichincreases
theriskofburninjuries.
—Afterinstallingacollapsiblesparetire,the
tirepressuremustbecheckedasquicklyas
possibletoreducetheriskofanaccident.
—Donotdrivefasterthan50mph(80km/h)
withthecollapsiblesparetire.Drivingfaster
thanthatincreasestheriskofanaccident.
—Avoidfull-throttleacceleration,heavybrak-
ing,andfastcorneringwiththecollapsible
sparetire,becausethisincreasestheriskof
anaccident.
—Neverdriveusingmorethanonecollapsible
sparetire,becausethisincreasestheriskof
anaccident.
—Normal tiresorwintertiresmustnot be
mountedonthecollapsiblesparetirerim.
®Note
Thecompressormustbe switchedoffafter12
minutesatthemosttoreducetheriskof
overheating.Letthecompressorcooldown
forseveralminutesbeforeusingitagain.
356