2020 MERCEDES-BENZ SLC ROADSTER Owner's Manual

Imp
ortant safety notes G
WAR
NING
When youdriveine me rge ncym ode,the
han dlingcharac teris tics are impa ired.e.g.
when cornerin g,when acceler ating stron gly
and when braking.Ther eisar isko fana cci-
den t.
Do note xcee dt he max imum specified
spee d.Avoid any abrup tsteer ing and driving
man euve rsas well asdriv ingoverobstac les
(cur bs,pot hole s,off -road). Thisapplie s,in
part icular,toaloade dvehicle.
St op driv ingineme rgencym odeify ou
no tice :
R ban gingn oise
R veh iclev ibration
R smo kewhic hsme llsliker ubb er
R co ntinuo usESP®
int erv ention
R crack sint he tire side walls
Af terd riving ineme rgencym ode,have the
rim schecked byaq ualif iedspec ialist work-
sho pwithr egard totheir further use. The
def ective tire must berep lace dine very
cas e. TIR
EFIT kit
Imp ortant safety notes TIRE
FITi sat ires ealan t.
You canuseTIRE FITt os eal pun ctures ofup to
0. 16 in(4 mm ),part icularly those inthet ire
tr ead. YoucanuseTIRE FITa toutside tempe ra-
tur es down to00F84‡( 00F820 †). G
WAR
NING
In thef ollowin gsituati onsinp articul ar,the
ti re sealan tisu nab leto pro vide sufficien t
bre akd own assistanc easitc anno tseal the
ti re pro perly:
R there arecutsorpunctures inthet ire
larg erthan those men tion ed pre viously.
R thew hee lrim isdamag ed.
R you havedriven atver ylow tire pre ssur es
or on aflat tire. Ther
eisar isko fana cciden t.
Do notd rivet he veh icle. Con tactaq ualified
spec ialist workshop. G
WAR
NING
The tire sealan tish armf uland caus esirrita-
ti on .Itm ust notc om eintoc ontac twithy our
sk in, eyes orclo thing orbe swallo wed.Do
no tinh ale TIRE FITf um es. Kee ptires ealan t
away from childr en.Ther eisar isko finjury.
If you come intoc ontac twitht he tire seal-
ant ,observ ethe followin g:
R Rins eoffthet ires ealan tfromy our skin
imm ediat elywithw ater.
R Ifth et ires ealan tcom esintoc ontac twith
your eyes, immediat elyrinse them thor-
ough lywit hc lean wat er.
R Iftire sealan tiss wallo wed, immediat ely
rin se your mout houtthoro ughly anddrink
plen tyof wat er.Do notind uce vom iting ,
and seek medicalattention imm ediat ely.
R Im med iately chang eoutofclo thing whic h
has come intoc ontac twitht ires ealan t.
R Ifan aller gicreac tion occur s,seek medi-
cal attention imm ediat ely.
! Do
noto per ate thet irei nflat ion compr es-
sor forlonger than eigh tminute satat ime
wit hout abreak. Itmay other wise overheat.
The tire inflat ion compr essorcan beoper -
ate dagain once ithas cooled down .
Comp lywit hthe man ufacturer’s safetyi ns truc-
ti on so nthe stick eron thet irei nflat ion com-
pre sso r. Flat
tire
255Break down assistance Z

Using
theTIREFIT kit X
Do not remov eanyforeign objectswhich
have penet rated thetire, e.g.screws or
nails.
X Remove thetire sealant bottle,the accom -
panying TIREFITstic ker and thetire inflat ion
compr essorfromthestowage wellunder-
neat hthe trun kfloor (Ypage 253).
X Aff ixpart 0043ofthe TIREF ITstic ker tothe
inst rumen tclust erwithin thedriver' sfield of
vision .
X Aff ixpart 0044ofthe TIREF ITstic ker near the
valve onthe wheel withthedefect ivetire. X
Remove fillerhose 0084and plug 0087from the
bott omsect ionofthe tire inflat ioncompr es-
sor housing.
X Slide theyellow fillerhose connectorinto
the mount ingonyellow cap0083oftire seal-
ant bott le0043 until theplug engages.
X With thesealing ringsinfron t,slide yellow
cap 0083oftire sealant bottle0043 intot he
mount ingoftire inflat ioncompr essor0044.
The capmust engage inboth hooks . X
Remove thecap from valve 006Bonthe faulty
tire.
X Sc rew filler hose 006Contothe valve.
X Ins ert plug 0087intot he cigaret telighter
sock et(Y page 230)orintoa1 2Vp ower
sock etinyour vehicle (Ypage 230).
X Turn theSmart Keytoposition 0047
(Y page 118)inthe ignit ionlock .
X Press onand offswitc h0085 onthe tire infla-
tion compr essortoON.
The tireinflat ioncompr essorisswitc hedon.
The tireisinflat ed.
First ,tire sealant ispumped intot he tire.
The pressure maybriefly risetoapprox-
imately 500kPa(5.0 bar/7 3psi).
Do not switch offthe tirei nflat ioncom-
pr essor during this phase.
X Let the tire inflat ioncompr essorrunfora
maximum often minut es.The tireshould
then have attained apressure ofat least
200 kPa(2.0 bar/29 psi).
If at ire pressure of200 kPa(2.0 bar/2 9psi)is
achieved afteramaximum often minut es,see
(Y page 257).
If at ire pressure of200 kPa(2.0 bar/29 psi)is
not achieved afteramaximum often minut es,
see (Ypage 257).
If tire sealant hasescaped, cleanitoff affec ted
areas asquickly aspossible. Itis prefer ableto
use clean water.
If your clothes aresoiled withtiresealant ,
have them cleaned withperch loroet hylene ata
dry cleaner assoon aspossible. 256
Flat
tireBr eakd ownassist ance

Tire
pres sure notreac hed If
at ire pre ssu reof200 kPa(2.0 bar/29 psi)
ha sb eena chieved after ten minutes:
X Swi tch offthe tire inflation comp ressor .
X Unsc rewthefillerh osef romt hevalve ofthe
fa ulty tire .
Note thattire sea lant ma yescap ew heny ou
uns crew thefillerh ose.
X Ver yslowly drive forwa rds orrev ers e
ap pro xim ately30 ft(10 m).
X Pu mp upthe tire again.
After amaxim um often minutes,the tire
pre ssu remu stbe atleas t2 00 kPa (2.0 bar/
29 psi). G
WA
RNING
If the required tire pressu reisnot reached
afte rthe spe cified time ,the tire istoo badly
da mag ed.The tiresealant cannot repairt he
tire inthis insta nce. Dama gedtiresand a
tire pressu rethat istoo low can signifi cantl y
imp airt he vehi cle'sbra king anddriving
cha racte ristics. Thereisar isko facci dent.
Do not continu edriving .Contact aqualifi ed
spe cialist wo rksho p.
Tire press urereac hed G
WARNI
NG
At ire tempo rarilys ealedw itht ire sea lant
imp airs the vehi cle'sdri ving characte ristics
and isnot suita blef or driving athig her
spe eds.The re isar isko fana ccident.
Ada ptyour driving styleacco rdingly and
dri ve care fully.D on otexcee dthe maxi mum
per mis siblespe edfor atire sea ledw itht ire
sea lant.
The maxi mum permis siblespe edfor atire
sea ledw itht ire sea lant is50 mph (80km/h ).
The upper partof the TIREFIT sticke rmustb e
affi xed tothe instru ment cluster inthe driver' s
fie ldof vis ion.
! Re
sid ue from thetire sealant may come
ou to fthe fillerh osea fteruse.T hisc ould
cau sestai ns.
The refo re,place thefillerh osei nt he plasti c
ba gw hich contai nedtheTIREFIT kit. H
En
viro nmen talnote
Have theused tire sealant bottl edispo sed
of pro fess iona lly, e.g. ataq ualifi ed spe cial-
ist worksho p.
If tire pressu reof200 kPa(2.0 bar/29 psi)
ha sb eena chieved afteram aximum period of
ten minu tes:
X Swi tch offthe tire inflation comp ressor.
X Unscre wthe fillerh osef rom thevalve ofthe
fau ltytire .
X Stow thetire sealant bottl eand the tire
infl ation comp ressor.
X Pul laway immedi ately.
X Stop afterdriving forappro xima telyten
minu tesand check thetire pressu rewith
the tire inflation comp ressor.
The tirepressu remus tnow beatleast
130 kPa(1.3 bar/19 psi). G
WARNI
NG
If the required tire pressu reisnot reached
afte rdriving forashortper iod,the tire istoo
ba dlyd am aged. The tiresealant cannot
rep airt he tire inthis insta nce. Dama ged
tire sand atire pre ssu rethat istoo low can
sig nifi cantl yimp airt he vehi cle'sbra king and
dri ving characte ristics. Thereisar isko f
acci dent.
Do not continu edriving .Contact aqualifi ed
spe cialist wo rksho p.
i In
case ssucha sthe one mentio ned
ab ove, contact anauthori zedMerce des-
Benz Center. Orcall1-800-FOR -MERCedes
(i nt he USA) or1-800-387-0100 (inC anad a).
X Co rrect thetire pressu reifit is stil latlea st
130 kPa(1.3 bar/19 psi).See theTirea nd
Loa ding Inform ation placa rdon the driver' s
sid eB -pillaro rthe tire pressu retab lein the
fue lfille rf lapf or val ues.
X To inc reas ethe tire press ure:switch on
the tire inflation comp ressor. Fl
at tire
257Breakdo wnassi stanc e Z

X
To reduc ethe tire pres sure :de pre sspre s-
su re release button 0043next topre ssu re
ga ge 0044.
X Whe nthe tire pressu reiscorr ect, unscrew
the fillerh osef rom thevalve ofthe sealed
tire .
X Screw thevalve cap onto thetire valve of
the sealedt ire. X
To rem ove thetire sealant bottle from the
tire inflation comp ressor ,press toge ther the
lo cking tabsonthe yellow cap .
X Pu llthe tire sealant bottle outo fthe tire
infl ation comp ressor .
The fillerh oser em ains atta chedtothe tire
sea lant bottle .
X Driv etot he nea restqualifi ed spe cialist
wo rksh opand have the tire changed there.
X Hav ethe tire sealant bottle and thefiller
hos ereplaced assoo naspossibl ea ta
qu alifi ed spe cialist wo rksh op.
X Hav ethe tire sealant bottle replaced every
fou ryears at aq ualifi ed spe cialist wo rksh op. Battery
(vehi cle) Impo
rtant safetynotes
Spe cialtool sand exp ertknow ledge are
req uired when working onthe battery ,e.g.
rem ovaland installatio n.Yo us houldt her efore
ha ve allw orki nvo lving the battery carriedo ut
at aq ualifi ed spe cialist wo rksh op. G
WAR
NING
Wor kcarrie do utinco rrectly onthe battery
can lead ,for exa mpl e,to as hortcirc uita nd
thu sdam aget he veh iclee lectro nics .This
can lead tofunc tionr estricti onsapplying to
sa fety -releva ntsystem s,e.g .the lighti ng
sy stem ,the ABS (anti-l ock braking system )
or the ESP ®
(El ectro nicStab ility Pro gram).
The opera ting safety ofyour veh iclem aybe
res tricte d.
Yo uc ouldlose contro lofthe veh icle, for
exa mpl e:
R wh en bra king
R in the eventofabrupt stee ring maneu vers
and /or when the vehicle's spe edisnot
ad apted tothe roadcond itions
The reisar isko fana ccident.
In the eventofas hortcirc uito ra simil ar
inci dent, conta ctaq ualifi ed spe cialist wo rk-
sho pimm ediatel y.Do not drive any further .
Yo us houldh avea llwo rkinvo lving the bat-
tery carriedo utataq ualifi ed spe cialist
wo rksh op.
For further informa tiona bout ABS andESP®
,
see (Ypage 57)and (Ypage 60). G
WAR
NING
Ele ctros taticbuild -u pc an lead tothe crea -
tio no fspa rks, which cou ldignite thehighl y
exp losive gases ofab attery .The re isar isk
of an exp losion.
Befo rehandl ing the battery ,tou ch the vehi-
cle body torem ove anyexisting electro static
bu ild-u p.
The highl yflamma bleg asmixtu reform swhen
cha rging the battery aswellas when jump -
sta rting . 25
8 Battery
(vehi cle)Breakdo wnassis tan ce

Alw
aysm akes uret hatn either youn orthe bat-
tery iselectro statica llyc harge d.Ab uild -u po f
el ectro static cha rge can becau sed,for exa m-
pl e:
R by wearing clothing ma de from syntheti c
fib ers
R du et ofrictio nbetwe en clothing and seats
R ifyo up usho rpullt he battery across the
car peto ro the rsyntheti cmateri als
R ifyo uw ipet he battery with ac loth G
WA
RNING
Dur ing the charging pro ces s,ab attery pro-
du ces hydro gen gas.Ifas hortcirc uito ccu rs
or spa rks arec rea ted ,the hydro gen gasc an
ig nite .The re isar isko fane xplosion.
R Ma kesure tha tthe positive term inalofa
conne ctedbattery does not come into
conta ctwith veh iclep arts.
R Nev erplace meta lobjects ortool sona
ba ttery .
R Itis imp orta nttha tyou obser vethe
de scri bedo rder ofthe battery terminals
wh en conne ctinganddisconne ctingabat-
tery .
R Whe njum p-sta rting,makes uret hatthe
ba ttery polesw ithi de nti cal polarity are
conne cted.
R Itis pa rticu larly imp orta ntto obser vethe
de scri bedo rder wh en conne ctinganddis-
conne ctingthejumperc ables.
R Nev erconne ctor disconne ctthe battery
term inalswh ilet he eng ineisrunning . G
WA
RNING
Batte ryaci disc austic.The reisar isko f
inju ry.
Avoi dconta ctwith ski n,eyes orclo thing. Do
not inhalea nybattery gases .Don otlean
ove rthe battery .Keepc hild ren away from
ba tteri es.Washaway battery acidimm edi-
ate lywith plenty ofcle an water and seek
med icalatte ntio n. H
En
viron men talnote Batte
riesc onta inpo lluta nts.
It is ille ga ltod ispo se of
them with the household
ru bb ish. The ym ustb ec ol-
le cted separate lyand dis-
po sed ofinan envi ronm en-
tal lyres ponsi bler ecy cling
sy stem . Dis
pose ofbatteri esinan
envi ronm entallyr espo nsi ble
ma nner. Take discha rged
ba tteri estoaq ualifi ed spe -
cia list wo rksh oportoac ol-
le ctio npoint for used bat-
teri es.
! Hav
ethe battery regular ly che cked ata
qu alifi ed spe cialist wo rksh op.
Co mpl ywitht he ser vice intervalsin the
Ma inte nance Booklet,or conta ctaq ualifi ed
spe cialist wo rksh opfor more informa tion.
! Alw
aysh avew orko nb atteri escar riedo ut
at aq ualifi ed spe cialist wo rksh op.
Shou ldit, inexce ptiona lcirc um stances ,be
ab sol ute lynece ssaryto disconne ctthe 12-
vol tbattery yoursel f,plea se obser vethe fol-
lo wi ng:
R Secu rethe vehiclet op revent itfrom roll-
ing away.
R Swi tch offthe igniti on.
R Dis conne ctthe negative term inalfirst and
then thepositive term inal.
The trans mission islocked inpo sitio n005D
afte rdisconne ctingthebattery .
After theworkhasb eend one,ins tallthe
ba ttery andreplace the cove rofthe positive
term inalclamp firmly .
Co mpl ywiths afety precau tions and take pro-
tecti vemea sures when handl ing batteri es. Ri
sk ofexp losion. Fir
e,op en flames andsmoking are
pro hibi ted when handl ing the bat-
tery .Avoi dc rea ting sparks. Battery
(vehi cle)
259Breakdo wnassis tan ce Z

Battery
acidisc austic. Avoid con-
tact with skin, eyes orcloth ing.
Wea rsuitabl eprote ctive clothing,
esp ecia llyg loves, apron and face-
gu ard .
Ri nse anyacids pillsi mme diatel y
wi th clea rwater. Contact aphysi-
cia nifn eces sary. Wea
reye prote ction. Kee
pchildre naway. Obs
erve thisOperator'sManu al.
For safety reasons, Merce des-Benz recom -
mends thatyouo nly use batterie swhich hav e
bee ntested andapprov edfor your vehi cleby
Merce des-Benz. Thesebatterie sprov ide
incre asedimp act prote ction topre vent vehicle
occu pants from sufferi ngacidb urns shou ld
the battery bedamag edinthe eventofan
acci dent.
In orde rfor the battery toachi evethemaxi -
mum possibleserv icelife, itmus talway sb e
suf ficiently charged.
Like other batterie s,the vehi clebattery may
di scha rgeover time ifyo ud on otuse thevehi -
cle. Inthis case ,havet he battery disconnec-
ted ataq ualifi ed spe cialist wor kshop .You can
al so char gethe battery with ac har ger recom -
mende dbyM erce des-Benz. Contact aquali-
fie ds pecia list wor kshop forfurth erinfor ma-
tion.
Have thebattery condi tionofchar gechecke d
more frequently ifyo uu sethe vehi clemai nly
for shor ttrip so rify ou leaveitstand ingidle
for aleng thy period.Consul taq ualifi ed spe -
cia list wor kshop ifyo uw isht oleave your vehi -
cle parked foralong period oftime .
Re move theSmartKe yify ou park the vehi cle
and donot require any electrica lconsu mers .
The vehiclewillthen usevery little energ y,
thus conser vingbattery power. If
the pow ersup plyh asbee ninterr upted, e.g.
if yo ur econne ctthe battery ,you willhav eto:
R rese tthe functi onfor automa ticallyf oldi ng
the exteri ormirr orsin/ou tbyfoldi ng the
mirr orsouto nce (Ypage 93)
R set the clock
On vehi cles with am ultimed iasystem, the
time isset automa tically. Charg
ingthe battery G
WARNI
NG
Duri ngchar ging andjump -starti ng,expl osive
ga ses can esca pefrom thebattery .The re is
ar isk ofan expl osion.
Pa rticu larly avo idfire ,ope nf lames, creating
spa rks and smoki ng.Ensure thereissuf fi-
cient ventilation whi lechar ging andjump -
starti ng.Donot leano ver abattery . G
WARNI
NG
Battery acidisc austic. Thereisar isk of
inju ry.
Avoid contact with skin, eyes orcloth ing.Do
not inha leany battery gases .Don otlea n
over thebattery .Keepc hildre nawayfrom
ba tterie s.Wa shaway battery acidimme di-
atel ywithp lenty ofclea nwater and seek
med icalattenti on. G
WARNI
NG
Ad ischa rged battery canfreezeattempe ra-
ture sbelow free zing point. Whe njump -start-
ing the vehi cleorchar ging thebattery ,
ga ses can esca pefrom thebattery .The re is
ar isk ofan expl osion.
All ow the frozen battery tothaw outb efore
char ging itor jump -starti ng.
! Only
usebattery chargers with am aximum
char ging voltage of14.8 V.
! On
lycha rge the battery using the jump -
star ting connecti onpoint.
The jump -starti ngconnecti onpointisin the
engi necomp artme nt. 260
Battery
(vehi cle)Breakdo wnassi stanc e

If
the indicator/wa rninglampsdon otlight up
at low temperature s,itis very likely thatthe
discha rgedbattery hasfrozen. Inthis case,
you may neither chargethebattery norjump-
start thevehicle .The service lifeofat hawed -
out battery maybeshorter. Thestarting char-
acteristics canbeimpa ired, particul arlyatlow
temperature s.Have thethawed -outbattery
checked ataq ualifie dspecia listworkshop.
Rea dthe battery charger's operatinginstruc-
tions before charging thebattery.
X Open thehood.
X Connect thebattery charger tothe positive
terminal andground pointinthe same order
as when connecting thedonor battery inthe
jump-starting procedure(Y page 261). Replaci
ngthe 12Vb attery
Observe thenotes onthe 12Vb attery
(Y page 258).
Mercedes-Benz recommendsthatyouhave
the 12Vb attery replacedataq ualifie dspe-
ciali stworkshop, e.g.atan authori zed
Mercedes-Benz Center. If
you want torepla cethe battery yourself,
observe thefollow ingnotes:
R Alway srepla cead efective batterywitha
battery whichmeets thespecific require-
ments ofthe vehicle .
The vehicle isequi pped withanAGM
(Absorbent GlassMat) technology battery.
Full vehicle functionality isonly guaranteed
with anAGM battery. Forsafety reasons,
Mercedes-Benz recommendsthatyouonly
use batteries whichhavebeen tested and
appro vedforyou rvehicle byMercedes-
Benz.
R Use detachab leparts suchasbreather
hoses, angled connecting piecesorterminal
covers fromthebattery whichisto be
repla ced.
R Make surethatthevent hose isalw ays con-
nected tothe origina lopening onthe bat-
tery side.
R Install existing orsupp liedcellcaps topre-
vent gases orbattery acidfrom escapi ng.
R Make surethatthedetachab leparts are
connected againinthe same way. Jump-star
ting
For thejump-starting procedure,use only thejump-starting connectionpointinthe engine com-
partment, consisting ofap ositive terminal andaground point. G
WARNING
Battery acidiscaustic. Thereisar isk ofinjury.
Avoid contact withskin, eyesorclothing. Donot inhal eanybattery gases.Don otlea no ver the
battery. Keepchildre nawayfrom batteries. Washawaybattery acidimmedi atelywithplenty of
clean water andseek medica lattention. G
WARNING
During charging andjump-starting, explosivegases canescape fromthebattery. Thereisa
risk ofan explosi on.
Particul arlyavoid fire,open flames ,creating sparksandsmoking. Ensurethereissufficie nt
ventilation whilecharging andjump-starting. Donot leano ver abattery. G
WARNING
During thecharging process,abattery produceshydro gengas. Ifas hort circuit occurs or
sparks arecreated, thehydro gengascan ignite. Thereisar isk ofan explosi on. Jump-st
arting
261Breakd owna ssis tance
Z

R
Make surethatthepositive terminal ofac onn ected battery doesnotcome intocontactwith
vehicle parts.
R Never placemetal object sortools onabattery.
R Itis important thatyouobserve thedescribed orderofthe battery terminals whenconnect-
ing and disconnec tingabattery.
R When jump-st arting,makesurethatthebattery poleswithidentical polarityareconn ected.
R Itis particularly importanttoobserve thedescribed orderwhenconnecting anddisconnec t-
ing the jumper cables.
R Never connectordisconnec tthe battery terminals whiletheengine isrunning. G
WARNING
Ad ischarged batterycanfreeze attemperatures belowfreezing point.Whenjump-st artingthe
vehicle orcharging thebattery, gasescanescape fromthebattery. Thereisar isk ofan explo-
sion.
Allow thefrozen battery tothaw outbefore charging itor jump-st arting.
! Avoid
repeated andlengthy startingattempt s.Otherwise, thecatalytic convertercould be
damaged bythe non- combusted fuel.
If the indicator/warnin glamps donot light upatlow temperatures, itis very likely thatthedis-
charged batteryhasfrozen .Int his case, youmay neither chargethebattery norjump-st artthe
vehicle. Theservice lifeofat hawed-out batterymaybeshorter. Thestartin gcharacterist icscan
be impaired, particularly atlow temperatures. Havethethawed-out batterycheckedataq uali-
fied specialist workshop.
Do not start thevehicle usingarapid charging device.Ifyour vehicle's batteryisdischarged, the
engine canbejump-st artedfromanother vehicleorfrom adonor battery usingjumper cables.
Observe thefollowing points:
R The battery isnot accessible inall vehicles. Ifthe other vehicle's batteryisnot accessible,
jump-st artthe vehicle usingadonor battery orajump-st artingdevice.
R You may onlyjump-st artthe vehicle whentheengine andexhaust systemarecold.
R Do not start theengine ifthe battery isfrozen .Let the battery thawfirst.
R Only jump-st artfrom batteries witha12V voltage rating.
R Only usejumper cableswhichhaveasufficient cross-sectionandinsulated terminalclamps.
R Ifthe battery isfully discharged, leavethebattery thatisbeing usedtojump-st artconn ected
for afew minutes beforeattempt ingtostart. Thischarges thebattery slightly.
R Make surethatthetwo vehicles donot touch.
Make surethat:
R The jumper cablesarenot damaged.
R Bare parts ofthe terminal clampdonot come intocontactwith other metal partswhile the
jumper cablesareconn ected tothe battery.
R The jumper cablescannot comeintocontactwith parts which canmove whentheengine is
running, suchasthe V-belt pulleyorthe fan.
X Secure thevehicle byapply ingthe electric parking brake.
X Shift thetransmission toposition 005D.
X Make surethattheignition isswitched off.Allindicator lampsinthe instrumen tcluster must
be off. When usingtheSmartK ey,turn theSmartK eytoposition 0092inthe ignition lockand
remove it(Y page 118). 262
Jump
-startingBr eakdown assistance