2021 MERCEDES-BENZ METRIS MY21 Operator's Manual

Af
terl eaving thec arwa sh, pa yattention tothe
fo llowing:
R The outsid emirro rs aref ullyf olded out again
and an additional antenna is mounted again.
R Waxresidues on thew indshield and wiper
ru bber sare re movedtop reve nt smearing and
re duce wiper noise.
Re mo ve wa xresidues from thec amera lens in
ve hicles wit harear vie wcamer a(/ pag e184). Note
sonu se ofapowerwa sher &
WARNING Risk of an accident when
using po werw ashe rswit hround-spr ay
nozzles
The wate rjet can cause extern all yinv isible
damage.
Component sdamaged in this wa ym ayunex‐
pec tedlyf ail. #
Do no tuse ap owerwa sher wit hround-
spra ynozzle s. #
Have damaged tires or chassis parts
re placed immediatel y. *
NO
TEDama getocomponent pa rtsd ue
to improper high-pressur ecleaning Components can be damaged if
thed istan ce
of theh igh-pressur enozzle is toos mall. #
Maintain aminimum dis tance of about
12 in (30 cm) between theh igh-pres‐
sur enozzle and car parts. #
Do no tuse ap owerwa sher wit ha
ro und-spr aynozzle. #
Keep thew ater je tmoving cons tantly
whil ecleaning. #
Do no tclean thef ollowing components
wit hthe po werw ashe r:
R Electrical components
R Plug connecto rs
R Rear vie wcamera
R Driv etra in
R Seals
R Hoses *
NO
TEDama gecaused bytheu se of a
po we rw ashe rinthevehicle interior The pressurized
watercreated bythep ower
wa sher and thea ssociated spr aycould cause
considerable damag etothevehicle. #
Neveru se ap owe rwashe rinthevehicle
interior. *
NO
TEDama getothee xhau stgasa fter‐
treatments thro ugh incor rect cleaning Cleaning
thes ystem when warm orthe
ef fects of direct waterjetsi ntot he exhaust
pipe can damag ethe exhaus tgas af tertre at‐
ment. #
Only clean thes ystemw hen thes ystem
is cold. #
Do no tdirect thew ater je tint ot he
ex haus tpipe. Wa
shing thee ngine
* NO
TEDama geand malfunctions due to
wa shing thee ngine #
Toprev ent damag eand malfunctions of
th ee ngine, obser vethef ollowing
points:
R When using high-pressur eorsteam
cleaners, do no tpoint thew ater jet
directly at electrica lcomponents
and thee nd of electric cables.
R Mak esuret hat no watere nter sthe
ve nt and ventilation openings.
R Use prese rvativ eagentsint he
engine af terw ashing thee ngine.
R Protect theb elt driv efromp reser va‐
tio na gents. Wa
shing thev ehicle byhand Obser
vethel egal requ irements, fore xamp le in
man ycountries washing byhand is onl yallowed
at speciall ydesignated wash ba ys. #
Washthev ehicle wit hlukew armw ater and a
sof tcar sponge. When doing so, do not
ex pose thev ehicle todirect sunlight. #
Use amild cleanin gagent,e .g.aM ercedes-
Benz appr ovedcar shampoo. Maintenanc
eand care 18 3

#
Carefull yspra ythe vehicle wit hwater and dry
of fw ithal eather clo th.Don otpoint the
wate rjet directly int othe air inle tgrille.
When operating thev ehicle in winter ,remo veall
traces of road salt deposits carefull yand as soon
as possible. Note
sonc areofp aint and matte finish *
NO
TEPaint wo rkdamag eand cor rosion
due toinadequat ecare Fa
ilur etop romp tly and thoroughly remo ve
dir tfromb irdd roppings or other residue
could result in paintwor kdamag eand cor ro‐
sion at alater date. #
Cleand irto ffpaint and matt efinish
th oroughly and as soon as possible. Obser
vethen otes on cleaning and car einorder
to avoid damag etothe paintwor k.
Pa int
R Insect remains: soak wit hinsect remo vera nd
th en wash off.
R Birdd roppings: soak wit hwater and then
wa sh off.
R Tree resin, oils, fuels and greases: remo veby
ru bbing gentl yw ithac loth soaked in petro‐
leum ether or lighter fluid.
R Coolan tand brak efluid: remo vewit had amp
clo thand clear water.
R Tars tains :use tarr emo ver.
R Wax: us eas ilicone remo ver.
R Do no taffix sticke rs,f ilms or similar.
R Remo vedirtass oon as possible.
Mat tefinish
R Onlyuse car eproducts appr ovedfor
Mercedes-Benz.
R Do no tpolish thev ehicle and allo ywheels.
R Onlyusestate-of- the-ar tcar wa shes.
R Do no tuse aw ash program that end switha
ho tw ax treatmen tinautom atic car washes.
R Do no tuse paint cleaners, buf fing or polish‐
ing products, or gloss preser vers,e .g. wax.
R Alwaysh ave paintwor krepair scarried out at
aq ualified specialis tworks hop. Note
sont he car eofvehicle parts &
WARNING Risk of inju ryif unsuitable
climbin gaids ar eused
If yo uu se opening sinthevehicle's body work
or de tach able parts as steps, youc ould:
R Slip and/or fall.
R Damag ethe vehicle and thus slip and fall. #
Alwaysu se anti-slip, stable climbing
aids, e.g .asuitable ladder. &
WARNING Risk of entrapment if the
windshield wiper sareswit ched on while
th ew indshield is being cleaned
If th ew indshield wiper saresetinm otion
while youa recleanin gthe windshield or
wiper blades, youc an be trapped bythew iper
arm. #
Alwayss witc hoffthew indshield wipers
and thei gnition befor ecleaning the
windshield or wiper blades. &
WARNING Risk of bu rnsf romt hetailpipe
and tailpipe trims
The exhaus ttailpipe and tailpipe trims can
becom everyh ot.Ify ou come int ocontact
wi th th ese parts of thev ehicle, youc ould
bur nyourself. #
Alwaysbep articularly careful around
th et ailpipe and thet ailpipe trims and
supervise children especially close lyin
th is area. #
Allowvehicle parts tocool down before
to uchin gthem. *
NO
TEDama gecaused bytheu se of
openings in theb odywor kordetachable
par tasa step Using
thel owe rguide of thes liding door (car‐
ri age) as astepc an damag ethe trim and/or
mechanism of thes liding door. #
Do no tuse theg uide of thes liding door
(car riage) as astep. %
Information on suitable cleaning agentsor
cleaning clo
thsc an be obtained from aquali‐
fi ed specialis tworks hop. 184
Maintenance and care

To
avo id damag etothevehicle, follo wt he
instructions forc leaning and car eofthefollowing
ve hicle parts:
Wheels and rims
R Use watera nd acid-free alloy wheel cleaner.
R Do no tuse acidic allo ywheel cleaner sto
re mo vebrak edust. Otherwise, wheel bolts
and brak ecomponents could be damaged.
R Toavo id cor rosion of brak ediscs and brake‐
pads, driv efor afew minutes af terc leaning
befor eparking thev ehicle. The brak ediscs
and brakepads warm up and dr yout.
Wi ndo ws
R Clean thew indo wsinside and outsid ewitha
dam pcloth and wit hacleaning agent recom‐
mende dfor Mercedes-Benz.
R Do no tuse dr ycloth sora brasiv eorsolvent-
based cleaning agents toclea nthe inside of
windo ws.
Wi per blades
R Carefully clea nthe folded-a wayw iper blades
wit had ampcloth.
R Fold wiper ar mawayfromt herear wind ow
( / pag e87).
R Do no tclean thew iper blades tooo ften.
Exterior lighting
R Clean thec oversw ithaw etspong eand mild
cleaning agent, e.g .car sha mpoo.
R Onlyuse cleaning agents or clo thss uitable
fo rp last ic co vers.
Sensors R Clean thes ensor sinthe front and rear bump‐
er sw ithas oftc loth and car shampoo
(/ page110).
R When using apowe rwashe r,ke ep am inimum
dis tance of 12in (30 cm).
Re ar vie wcamera
R Vehicles with atailgate: switc hont he igni‐
tion and shif tthe transmission tothe 005Eposi‐
tion toopen thec amera co verw hen the
engine is switched of f(/pag e110).
R Usec lean wate rand asoftc loth toclea nthe
camer alens.
R Do no tuse ap owe rwashe r. Sliding door
R Remo vefore ign object sfromt he vicinity of
th ec ontact plates and contact pins of the
sliding door.
R Cleant he contact plates and contact pins
wit ham ild cleaning agent and asoftc loth.
R Do no toilor grease thec ontact plates and
th ec ontact pins.
Ta ilpipes
R Clean wit hacleanin gagent recommended for
Mercedes-Benz, especially in thew inter and
af te rw ashing thev ehicle.
R Do no tuse acidic cleaning agents.
Tr aile rhitch
Obse rvet he no tesonc areint he trailer hitch
manufacturer's operating instructions. Note
soni nterior care &
WARNING Risk of inju ryfrom pla stic
parts breakin goffafte rt he use of sol‐
ve nt-based care products
Ca reand cleaning products con tainin gsol‐
ve nts can cause su rfaces in thec ockpit to
become porous. When thea irbags are
deplo yed, plastic parts ma ybreak away. #
Do no tuse anyc areorc leaning prod‐
ucts containing sol vents toclea nthe
cockpit. &
WARNING Risk of inju ryor deat hfrom
bleached seat belts
Bleaching or dyeing seat belts can se verely
we aken them.
This can, fore xamp le, cause seat belt stotear
or fail in an accident. #
Neverb lea ch or dy eseat belts. To
avo id damag etothevehicle, obser vethef ol‐
lowing instructions forc leaning and care:
Seat belts
R Clean wit hlukewa rmsoap ywater.
R Do no tuse chemical cleaning agents.
R Do no tdryby heating abo ve176°F( 80 °C)
or in direct sunlight. Maintenance and care
18 5

Display
R Switc hoffthed ispla yand le titcool down.
R Clean thes urface carefully wi tham icro fiber
clo thand asuitable displa ycarep roduc t(TF T-
LC D).
R Do no tuse anyo ther agents.
Plastic trim R Clean wit hadampm icrofiber clo th.
R Forh eavy soiling: use acleaning agent rec‐
ommended forM ercedes-Benz.
R Do no taffix sticke rs,f ilms or similar.
R Do no tallowtoc ome int ocontact wi thcos‐
metics, insect repellent and sun creams.
Headliner
R Clean wit habrush or dr yshampoo.
Carpet R Use acarpe tand textil ec leaning agent rec‐
ommended forM ercedes-Benz.
Genuine leather seat co vers
R Clean wit hadampcloth and then wipe wit ha
dr yc loth.
R Leather care: use aleather car eagent recom‐
mende dfor Mercedes-Benz.
R Do no tclean thel eather wit htoo muc hliquid.
R Do no tuse am icrofiber clo th.
Seat co vers made of artificial leather
R Clea nwithad ampcloth and 1% soap ywater.
R Do no tuse am icro fiber clo th.
Clo thseat co vers
R Clean wit hadampm icro fiber clo thand 1%
soap solution and allo wtodry.
Genuin eleather steering wheel
* NO
TEDama gecaused bywrong cleaners #
Do no tuse solvent-based cleaning
agent ssuchast arremo verorw heel
cleaner ;neither should youu se polishes
or wa xes. Otherwise youm aydamage
th ef inish. R
Clean wit hadampcloth and 1% soap ywater
and wipe wit hadryclo th.
R Forh eavy soiling: use acleaning agent rec‐
ommended forM ercedes-Benz.
R Vehicles wit hleather uphols tery :u se a
leather car eagent recommended for
Mercedes-Benz. R
Do no tclean thel eather wit htoo muc hliquid.
R Do no tuse am icrofiber clo th.
% Leather is
anatural product. It has natural
sur face characteristics, e.g .diffe re nces in
st ru cture, trace sofgrowt ha nd injur yor
sligh tcolor nuances.
Re alwo od and trim elements
R Clean wit hamicro fiber clo th.
R Blackpiano-lacquer look: clean wit hadamp
clo thand soap ywater.
R Forh eavy soiling: use acleaning agent rec‐
ommended forM ercedes-Benz.
R Do no tuse sol vent-based cleaning agents,
polishes or waxes. 18 6
Maintenance and care

Emer
gency Re
moving the saf etyv est The saf
etyv estisl ocated in thed oor storage
compartmentint he driver's door. #
Take thes afet yv esto ut of thed oor storage
compartment.
% Saf
etyv ests can also be stored in thed oor
st orag ecompartmentoft he co-driver's door. 1
Maximum number of washes
2 Maximum wash temp erature
3 Do no tbleach
4 Do no tiron
5 Do no ttumble dry
6 Do no tdry-clean
7 Thisisac lass2vest
The saf etyv esto nlyf ulfills thel egally required
st andards if it is thec orrect size and is com‐
ple tely closed.
Re place thes afet yv estint hefollowing cases:
R If damaged or if ther eflectiv estrip saredirty
R Ifth em aximum permitted number of washes
is exc eeded
R Ifth es afet yv est's fluorescenc ehasfaded Re
moving the firs t-aid kit (sof tsided) The
firs t-ai dkit (sof tsided )islocated in thes tor‐
ag ec ompartmentint he co-driver door. #
Remo vefirs t-ai d(softsided) kit from thes tor‐
ag ec ompartment.
Chec kthe expiration dat eonthefirs t-ai dkit (soft
sided) at leas tonce ayear .Replace an yexpi red
or missing con tents.
Obser vethel egal requ irements of thec ount ryin
whic hyou ar ecurrently driving. Mercedes-Ben
zeme rgency call sy stem Information on
theM ercedes-Benz emer‐
ge ncy call sy stem &
WARNING Risk of distraction from infor‐
mation sy stems and communications
equipment
If yo uo perat einformation and communica‐
tio ne quipment integ ratedint hevehicle when
driving, youw ill be distracted from thet raffic
situation. This could also cause youtol ose
control of thev ehicle. #
Onlyoperat ethis equipment when the
traf fics ituation permits. #
Ifyo uc anno tbes ureoft his,stop the
ve hicle whils tpaying attention toroad
and traf ficc onditions and ope rate the
equipment wit hthe vehicle stationar y. Obser
vethel egal requ irements fort he countr yin
whic hyou ar estaying.
The Mercedes-Benz emer gency cal lsyst em only
functions in areas wher emobile phone co verage
is available from ther ele vant contract pa rtner.
Insu fficien tnetwo rkcoverage from ther ele vant
contract pa rtner ma yresult in an emer gency call
no tb eing transmitted.
The Mercedes-Benz eme rgency call sy stem can
help todecisivel yreduce thet ime between an
accident and thea rrival of emer gency service sat
th es iteoft he accident. It helps locat eanacci‐
dent sit einplaces that ar edifficul ttoa ccess.
An emer gency cal lcan be initia teda utomatically
or manually using theS OS button (/ page188).
Onl ym akee mer gency calls if youoro ther sa rein
need of rescue. Do no tmakeane mergency call
in thee vent of abreak down or asimilar situation.
Ad ditional information on thet ransfer redd ata
(/ page189).
Yo uc an find mor einformation on ther egional
av ailabilit yofthe Mercedes-Benz emer gency call
sy stem at :https://www.mercedes-benz-
mobile.com/extra /ecall/ Displa
ysinthei nstrument clus ter Af
tert he ignition is switched on, amessage
appear sinthe instrument clus teri ndicating
whe ther your vehicle can be located. Breakdown assis
tance 187

On
vehicles without steering wheel buttons, the
x Trackin gActive orx Trackin gnot
Active messag ebriefly appears.
On vehicles wit hsteering wheel buttons, the
x symbol is only then shown in thes tatus
area if thep ositioning function is active.
SOS NOT READY:T he ignition is notswitched on
or thee mer gency cal lsyst em is malfunctioning.
SOS READY:T he emergency cal lsystemisa vaila‐
ble again, af teram alfunction fore xamp le.
During an activ eemer gency cal lthe 0053 symbol
and various messages about thes tatus of the
emer gency cal lappea rinthe displa y.
If th ee mer gency cal lsyst em is malfunctioning,
th ei nstrument clus terd ispla ysac orresponding
message. Tr
iggering an automatic Mercedes-Benz emer‐
ge ncy call Re
quirements:
R The ignition is switched on.
R The star terb atter yiss ufficiently charge d.
If re stra int sy stems suc hasairbags or Emer gency
Te nsioning Device shave been activated af teran
accident, eCall ma yautomatically initia tean
emer gency call.
Whe nthe emer gency cal lismade:
R Avoice connection is made totheM ercedes-
Benz emer gency cal lcenter.
R Am essa gewitha cciden tdataist ransmit ted
to theM ercedes-Benz emer gency cal lcenter.
The Mercedes-Benz eme rgency call center
can transmit thev ehicle position dat atoone
of thee mer gency cal lcenters.
The SOS button in theo verhead cont rolp anel
fl ashes until thee mer gency cal lisfinished.
It is no tpossible toimmediatel yend an auto‐
matic emer gency call.
If no connection can be mad etothe emergency
servic es: #
Dialthe local emergency num berony our
mobile phone.
If an emer gency cal lhas been initia ted:
R Remain in thev ehicle if ther oad and traf fic
conditions permit youtodosou ntilavoice connection is es
tablished wit hthe emergency
call cen tero perator.
R Base dont he call, theo perator decides
whe ther it is necessar ytocallr escue teams
and/or thep olice tothea ccident site.
R If no vehicle occupant answers, an ambu‐
lance is sent tothev ehicle immediatel y. Tr
iggering amanual emer gency call Requ
irements:
R The ignition is switched on.
R The star terb atter yiss ufficiently charge d.
If re stra int sy stems suc hasairbags or Emer gency
Te nsioning Device sareacti vatedd uring an acci‐
dent ,the Mercedes-Benz emer gency cal lsyst em
automaticall yinitiates an emer gency call.
Initiatin ganemergency call manuall yusing
th eS OS but tonint heove rhead control panel #
Toopen, briefly press co ver1forS OS but‐
ton 2. #
Press and hol dthe SOS button foratl east
one second.
The indicator lam pinSOS button 2flashes
until thee mer gency cal lisfinished.
When thee mer gency cal lismade:
R Avoice connection is made totheM ercedes-
Benz emer gency cal lcenter.
R Am essa gewiththe accident dat aistransmit‐
te dtot he Mercedes-Benz emer gency call
center.
The Mercedes-Benz emergency cal lcenter
can transmit thev ehicle position dat atoone
of thep ublic emer gency service scallc enters. 18 8
Breakdown assis tance

R
Remain in thev ehicle if ther oad and traf fic
conditions permit youtodosou ntilavoice
connection is es tablished wit hthe emergency
call cen tero perator.
R Base dont he call, theo perator decides
whe ther it is necessar ytocallr escue teams
and/or thep olice tothea ccident site.
R In cer tain situations dat aisalso transmitted
in thev oice channel totheM ercedes-Benz
emer gency cal lcenter.
Thi sallow sm easu resf or rescue, reco very or
to wing toaM ercedes-Ben zCommercial Van
Center tobe initiated quickl y.
If th eM ercedes-Benz emer gency cal lsyst em can‐
no tc onnect totheM ercedes-Benz emer gency
cal lcenter ,the emergency call is automatically
sent tothep ublic emer gency service scallc enter.
If no connection can be mad etothe public emer‐
ge ncy services, acorresponding message
appears inthed ispla y.In this case youm ustd ial
th ee mer gency cal lnumber 11 2onyour mobile
phone.
Ending an unin tentional emer gency call #
Vehicles without steering wheel but tons:
press the0078button in thei nstrument clus ter. #
Vehicles with steering wheel but tons:
press the0076 button on thes teering wheel. #
Close theS OS button co ver Data trans
feroft he Mercedes-Ben zemer‐
ge ncy call sy stem In
thee vent of an au tomatic or manua lemer‐
ge ncy call, as well as fora 11 2 emer gency call,
da ta is transmitte dtothe Mercedes-Benz emer‐
ge ncy cal lcenter or thep ublic emer gency serv‐
ice scallc enter.
The following dat aistransmit ted:
R Vehicle's GPS position data
R (GPS position dat aontheroute(af ewhundred me ters befor ethe incident))
R Direction of tr avel
R Vehicle identification number
R Vehicle driv etype
R Number of persons on thef ront seats
R Whe ther thee mer gency cal lwas initia ted
manually or automatically
R Time of thea ccident
R Languag esetting Fo
ra ccident clarificatio npurposes ,the following
measures can be take nu ptoa nhour af tert he
emer gency cal lhas been initia ted:
R The cur rent vehicle position can be called up
R Avoice connection tothev ehicle occupants
can be es tablished Flat tire
Note
sonf lat tires &
WARNING Risk of accident du etoaflat
tire
Af lat tir eaffects thed riving characteristic sof
th ev ehicle. #
Do no tdrive wit haf lat tire. #
Replace thef lat tir ewitht he emer gency
spa rewheel or spar ewheel. Alterna‐
tivel y,consult aqualified specialist
wo rkshop. Yo
uw illfind astickerw itht he Mercedes-Benz
Service24h telephon enumbe ronthe B-pillar on
th ed rive r's side, fore xamp le.
Fo rv ehicles wit hasparew heel, information in
th ee vent of aflat tir ecan be found under
"Wheels and tires" (/ page216). Battery
Note
sont hestar terb attery Wo
rkon theb atter y,e.g. removing or ins talling,
requ ires specialis tknowledg eand theu se of spe‐
cial tools. Therefore, alw aysh ave workon the
batter ycarried out at aqualified specialis twork‐
shop. &
WARNING Risk of an accident du eto
wo rkcar ried out incor rectl yont he bat‐
te ry
Wo rkcar ried out incor rectly on theb attery
can, fore xamp le, lead toas hor tcircuit .This
can restrict functions releva nt fors afet ys ys‐
te ms and impairt he operating saf etyofy our
ve hicle. Breakdown assis
tance 18 9

Yo
uc oul dlose control of thev ehicle in the
fo llowing situations in particular:
R When braking
R Inthee vent of ab rupt steering maneuvers
and/or when thev ehicle's speed is not
adap tedtot heroad conditions #
Inthee vent of ashortcircui tora simi‐
la ri ncident, contact aqualified special‐
is tw orks hop immediately. #
Do no tdrive on. #
Alwaysh ave workon theb atter ycarried
out at aqualified specialis tworks hop. R
Further information on ABS (/ page111 )
R Further information on ESP ®
(/ page111 )
Fo rs afet yr easons, Mercedes-Benz recommends
th at youo nly use bat teries that ha vebeen tested
and appr oved fory our vehicle byMercedes-Benz.
These batteries pr ovide inc reased impact pr otec‐
tion toprev ent vehicle occupants from suf fering
aci db urns should theb atter ybed amaged in an
accident. &
WARNING Risk ofexplosion due toelec‐
tros tatic charge
Electros tatic charge can igni tetheh ighly
ex plosiv egas mixtur einthe batter y. #
Todischar geanye lectrostatic charge
th at ma yhave built up, touc ht he me tal
ve hicle body befor ehandling theb at‐
te ry. The highly
flammable gasm ixtur eisc reated while
th eb atter yisc harging and when jump-s tarting.
Mak esuret hat neither youn ortheb atter yis
electros tatically charge d.
Elect rostatic charge can occu rinthefollowing
cases ,for example:
R Youa rewe aring synthetic clo thing.
R Ther eisf riction between your clo thing and
th es eat.
R Youd ragorp ushtheb atter yacross acarpet
or other synthetic materials.
R Your ub theb atter ywithc loth sort owels. &
WARNING Danger of chemical burns
from theb atter yacid
Batter yacid is caustic. #
Avoid contact wit hthe skin, eyes or
clo thing. #
Do no tlean overthe batter y. #
Do no tinhal ebattery gases. #
Keep children away from theb atter y. #
Immedia tely rinse batter yacido ffthor‐
oughly wit hplenty of clean waterand
seek medica lattention immediately. +
ENVIRONMENTAL
NOTEEnvironmental
damag eduetoimproper disposal of bat‐
te ries Batteries contain pollutants. It is
illegal todispose of them wit hthe household
ru bbish. #
Dispose of batteries in an
environmen tallyr esponsibl emanner.
Ta ke dischar gedb atteries toaq ualified
specialis tworks hop or toac ollection
poin tfor used batteries. Obser
vethes afet yn otes and pr otectiv emeas‐
ures when handling batteries. Risk of
explosion Fire, open
flames and smokin gare
prohibited when handlin gthe batter y.
Av oid creating spar ks. Electrolyte
or batteryacid is cor ro‐
sive. Avoid contact wit hthe skin, eyes
and clo thing. Wear suitable pr otective
clo thing, in particular glove s, an apron
and asafet ym ask. Immedia tely rinse
electrolyt eacids plashes of fwith
clea nwater .Ifn ecessar y,seek medi‐
cal advice. We
areyep rotection. 19 0
Breakdown assis tance