2021 MERCEDES-BENZ B-CLASS HATCHBACK warning light

Then,
you can select a service and be connected
to a specialist at the Mercedes-Benz Customer
Centre.
Calling t
Calling t he Mer he Mercedes-Benz Cust
cedes-Benz Cust omer Centr
omer Centre
eaTer
aTer
aut
aut omatic accident or br
omatic accident or br eakdo
eakdown det
wn det ection
ection
R
R eq
eq uir
uir ements:
ements:
R The vehicle has de tected an accident or break-
down situation.
R The vehicle is stationar y.
R The hazard warning lights are switched on.
% This function is not available in all countries.
The vehicle can de tect accident or breakdown sit-
uations under cer tain circumstances.
In theev ent an accident or breakdown is de tec-
te d, the emer gency guide sh ows saf ety no tes in
th e multimedia system displa y.
ATer quitting the emer gency guide display on the
multimedia system, a prom ptappears asking
whe ther youwo uld like toget support from the
Mercedes-Benz Customer Centre. #
Select Call.
R ATer your ag reement, or if the Mercedes
me connect service "Accident and Break-
down Management" is active, theve hicle
data is transfer red automatically
(/ page 319).
R The Mercedes-Benz Customer Centre
ta ke syo ur call and or ganises the break-
down and accident assistance.
Yo u may be charge dfo rth ese services.
% Depending on the se verity of the accident, an
automatic emer gency call can be initia ted.
This has priority over all other active calls.
% In addition, if the Mercedes me connect
service "Telediagnostics" is active, a similar
prom ptcan appear aTer a delay in theev ent
of a breakdown. If you are already in contact
with the Mercedes-Benz Customer Centre or
ha ve already received support, this prom pt
can be ignored or declined.
% Ifyo u answer the prom ptfor support from the
Mercedes-Benz Customer Centre with Later,
th e message will be hidden and appear again
later. The prom
pttriggered bythe Mercedes me
connect service "Telediagnostics", can either
be con/ rmed or declined. ATer being
declined, this will not be shown again.
Arr Arr anging a ser
anging a ser vice appointment via a Mer
vice appointment via a Mer cedes
cedes
me call
me call
If yo u ha veactivated the maintenance manage-
ment service, releva nt vehicle data is transfer red
automatically tothe Mercedes-Benz Customer
Centre. You will then receive individual recom-
mendations rega rding the maintenance of your
ve hicle.
Re gardless of whe ther you ha veconsen tedto the
maintenance management service, the multime-
dia system reminds you aTer a cer tain amount of
time that a service is due. A prom ptappears ask-
ing if youwo uld like tomake an appointment. #
T To arr
o arr ang
ange a ser
e a ser vice appointment
vice appointment: :select Call.
ATer your ag reement, theve hicle data is
transfer red and the Mercedes-Benz customer
centre take syo ur prefer red appointment date.
The information is then sent toyour desired
service outlet. 316
316
MBUX multimedia system

R
Frequent operation in mountainous terrain or
on poor road sur faces
R When the engine is oTen leT idling for long
periods
R Operation in particular lydusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air /lter, air /lter, engine oil and oil /lter,
fo rex ample, changed more frequentl y.The tyres
must be checked more frequently if theve hicle is
operated under increased loads. Further informa-
tion can be obtained at a quali/ed specialist work-
shop. Batt Batt
er
ery disconnection per
y disconnection per iods
iodsThe AS
SYST PLUS service inter val display can cal-
culate the service due date only when the battery
is connected. #
Display and no tedown the service due date
on the inst rument display before disconnect-
ing the battery (/ page 336). Engine com
Engine com
par
partment
tment A
A
ctiv
ctiv e bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otection)
ection) Oper
Oper
ation of t
ation of t he activ
he active bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otec-
ec-
tion)
tion)
In cer tain accident situations, the actuation of the
active bonnet reduces therisk of injury topedes-
trians. The rear area of the bonnet is raised by
appr oximately 70 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonnet yourself (/ page 337).
ATer the active bonnet has been actuated, pedes-
trian pr otection may be limited.
Ha ve the full functionality of the active bonnet
re stored in a quali/ed specialist workshop.
R
R ese ese tting t
tting t he activ
he activ e bonnet
e bonnet &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. #
With your hand 0at, push down active bonnet
1 inthe area around the hinges on bo th
sides (ar rows ).
In doing so, the actuator is depressurised and
yo u may hear a hissing sound.
The engine bonnet must engage in position. #
Ifth e active bonnet can be raised slightly at
th ere ar in the area of the hinges, repeat the
step until it engages co rrectl y. Maintenance and ca
re
337
337

#
Ifth e bonnet can still be liTed slightl y,open
th e bonnet again and close it with a little force
until it engages cor rectl y. Engine oil
Engine oil
Chec
Chec
king t
king t he engine oil lev
he engine oil lev el using t
el using the on-board
he on-board
com
com put
puter
er
R
R eq
eq uir
uir ements:
ements:
R The engine has been warmed up.
R The vehicle is par ked on a le vel sur face.
R The engine is running at idle speed.
R The bonnet is closed.
The engine oil le vel is de term ined during driving.
De term ining the engine oil le vel can take up to
30 minutes with a normal driving style and even
longer with an active driving style. On-board computer:
4 Service 5
Engine oil level
One of thefo llowing message s will appear onthe
inst rument displa y:
R Engine oil level Measuring now: measu rement
of the oil le vel is not yet possible. #
Repeat there qu est aTer a maximum of
30 minutes' driving.
R Engine oil level OK andthe bar display for
indicating the oil le vel on the inst rument dis-
play is green and is between "min" and "max":
th e oil le vel is cor rect.
R Engine oil level Add 1,0 l andthe bar display
fo r indicating the oil le vel on the inst rument
display is orange and is below "min": #
Add 1 l of engine oil.
R Reduce engine oil level andthe bar display for
indicating the oil le vel on the inst rument dis-
play is orange and is abo ve"max": #
Drain o. any excess engine oil that has been
added. Todo so, consult a quali/ed specialist
wo rkshop.
R For engine oil level turn on ignition #
Switch on theve hicle tocheck the engine oil
le ve l.
R Engine oil level System inoperative: The oil
leve l sensor is defective or not connected. #
Consult a quali/ed specialist workshop.
R Engine oil level System currently unavail. #
Close the bonnet.
T T opping up engine oil
opping up engine oil &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. 340
340
Maintenance and care

Ext
Ext
er
erior lighting
ior lighting
R Clean the lenses with a wet sponge and mild
cleaning agent, e.g. car sha mpoo.
R Only use cleaning agents or cleaning clo ths
th at are suitable for plastic lenses.
V
V ehicle soc ke
ehicle soc ket (high-v
t (high-v olt
oltag
age batt
e batt er
ery)
y)
R Use clean water and a soT clo thtoclean the
ve hicle soc ket.
R Do not use high-pressure cleaners or cleaning
agents, such as soap.
Sensors
Sensors
R Clean the sensors in the front and rear bump-
ers with a soT clo thand car shampoo
(/ page 223).
R When using a high-pressure cleaner, main tain
a minimum distance of 30 cm.
Rev Rev er
ersing camer
sing camer a and 360° Camera
a and 360° Camera
R Use clean water and a soT clo thtoclean the
camera lens.
R Do not use a high-pressure cleane r.T
T ailpipes
ailpipes
R Clean with a cleaning agent recommended for
Mercedes-Benz, especially in the winter and
aTer washing theve hicle.
R Do not use acidic cleaning agents.
Tr
Tr ailer hitch
ailer hitch
R Obser vethe no tes on care in the trailer hitch
manufacturer's operator manual.
R Do not clean the ball neck with a high-pres-
sure cleaner or sol vent.
R Remo vetraces of rust on the ball, forex ample,
with a wire brush.
R Remo vedirt with a lint-free clo th.
R ATer cleaning, lightly oil or grease the ball
head.
% Before using trailers with anti-torsional cou-
pling, obser vethe manufacturer's operator
manual. N No
ot
tes on car
es on car e of t
e of t he int
he int er
erior
ior &
W
WARNING
ARNING Risk of injury from plastic parts
breaking o. aTer the use of sol vent-based
ca re products
Care and cleaning products containing sol-
ve nts can cause sur faces in the cockpit to
become porous. When the airbags are
deplo yed, plastic parts may break away. #
Do not use any care or cleaning products
containing sol vents toclean the cockpit. &
W WARNING
ARNING Risk of injury or fatal injuries
from bleached seat belts
Bleaching or dyeing seat belts can se verely
we aken them.
This can, forex ample, cause seat belts to tear
or fail in an accident. #
Never bleach or dye seat belts. To
avo id damage totheve hicle, obser vethefo l-
lowing no tes on cleaning and care: Main
tenance and ca re
349
349

&
W
W ARNI NG
ARNI NGRisk of explosion from a frozen
battery
A dischar ged battery may freeze at temp era-
tures slightly abo veor below freezing point.
During starting assistance or battery charging,
battery gas can be released. #
Always allow a battery tothaw before
ch arging it or per form ing starting assis-
ta nce. If
th e indicator/warning lamps in the inst rument
cluster do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has frozen.
In this case you may neither jump-start theve hi-
cle nor charge the batter y.
The service life of a bat tery that has been thawed
may be dramatically shor tened. The starting char-
acteristics may be impaired, especially at low
te mp eratures.
It is recommended that you ha veath awe d battery
ch ecked at a quali/ed specialist workshop. *
N
NO OTE
TE Damage caused bynume rous or
ex tended attem ptsto start the engine Numerous or
extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combusted fuel. #
Avoid numerous and extended attem pts
to start the engine. Obser
vethefo llowing points during starting assis-
ta nce and when charging the batter y:
R Only use undamaged jump lead/charging
cables with a su1cient cross-section and
insulated term inal clamps.
R Non-insulated parts of thete rm inal clamps
must not come into contact with other me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-start connec-
tion point.
R The jump lead/charging cable must not come
into contact with any parts which may mo ve
when the engine is running.
R Always make sure that nei ther you nor the bat-
te ry is electros tatically charge d. R
Keep awa y from /re and naked 0ames.
R Do not lean overth e batter y.
Obser vethe additional following points when
ch arging the batter y:
R Only use battery charge rs tested and
appro vedfo r Mercedes-Benz.
R Read the battery charge r's operating inst ruc-
tions before charging the batter y.
Obser vethe additional following points during
starting assistance:
R For starting assistance, only use batteries with
a nominal voltage of 12 V.
R The vehicles must not touch.
R P
P e etr
tr ol engine:
ol engine: only accept starting assistance
if th e engine and exhaust system are cold. S
S
t
tar
ar ting assist
ting assist ance and c
ance and c har
harging t
ging t he 12 V batt
he 12 V batt ery
ery R
R
eq
eq uir
uir ements:
ements:
R The vehicle is secured with the electric par k-
ing brake. Breakdown assistance
363
363

R
if operating conditions change, e.g. o.-
ro ad driving #
Adjust the tyre pressure, if necessar y.Ty
re pressure which is too high or too low can:
R Shor tenth e service life of the tyres.
R Cause increased tyre damage.
R Adve rsely a.ect driving characteristics and
th us driving saf ety, e.g. due toaquaplaning. &
W
WARNING
ARNING Risk of accident due torepea-
te d pressure drop in the tyres
The wheels, valves or tyres could be damaged.
To o low a tyre pressure can lead tothe tyres
bursting. #
Examine the tyres forfo re ign objects. #
Check whe ther the tyre has a puncture
or theva lve has a leak. #
Ifyo u are unable torectify the damage,
contact a quali/ed specialist workshop. Information on
there commended tyre pressure
fo rth eve hicle's factor y-/tted tyres can be found
on the tyre pressure table on the inside of the fuel
/ller 0ap (/ page 376).
Use a suitable pressure gauge tocheck the tyre
pressure. The outer appearance of a tyre does not
permit any reliable conclusion about the tyre pres-
sure.
Only cor rect tyre pressures when the tyres are
cold. Conditions for cold tyres:
R The vehicle has been par ked with the tyres out
of direct sunlight for at least thre e hours.
R The vehicle has tr avelled less than 1.6 km.
The vehicle's tyres heat up when driving. As the
te mp erature of the tyres increases, so too does
th e tyre pressure.
V
V ehicles wit ehicles wit h a tyr
h a tyre pr
e pressur
essur e monit
e monit or
oring syst
ing syst em:
em:
yo u can also check the tyre pressure using the
on-board computer.
Not
Not es on tr
es on tr ailer oper
ailer oper ation
ation
Alw ays in0ate there ar axle tyres tothere com-
mended tyre pressures on the tyre pressure table
fo r increased load. T
T
yr
yr e pr
e pr essur
essur e t
e table
able The tyre pressure
table is on the inside of the fuel
/ller 0ap. The tyre pressure
table sho ws there commended
tyre pressure for all tyres appr ovedfo rth is vehi-
cle. The recommended tyre pressures apply for
cold tyres under various operating conditions, i.e.
loading and/or speed of theve hicle. 376
376
Wheels and tyres

%
V
Vehicles wit
ehicles wit h a tyr
h a tyre pr
e pressur
essur e loss w
e loss w ar
arning
ning
syst
syst em:
em: if an emer gency spa rewheel is /tted,
th e tyre pressure loss warning system cannot
function reliabl y.Only restart the system
again when the emer gency spa rewheel has
been replaced with a new wheel.
V
V ehicles wit
ehicles wit h a tyr
h a tyre pr
e pressur
essur e monit
e monit or
oring sy
ing sy s-
s-
t
t em:
em: if an emer gency spa rewheel is /tted, the
tyre pressure monitoring system cannot func-
tion reliabl y.Fo r a few minutes aTer an emer-
ge ncy spa rewheel is /tted, the system may
still display the tyre pressure of there mo ved
wheel. Only restart the system again when the
emer gency spa rewheel has been replaced
with a new wheel.
Be sure toalso obser vethefo llowing fur ther rela-
te d subjects:
R Notes on tyre pressure (/ page 375)
R Tyre pressure table (/ page 376)
R Notes on /tting tyres (/ page 379)
R Fitting an emer gency spa rewheel
(/ page 383) In0ating
In0ating
t
the emerg
he emerg ency spar
ency spar e wheel
e wheel *
N
NOOTE
TE Overheating due tothe tyre in0ation
compressor running too long #
Do not runth e tyre in0ation compressor
fo r longer than ten minutes without inter-
ru ption. R
R
eq
eq uir
uir ements:
ements:
The emer gency spa rewheel has been /tted cor-
re ctl y. ( / page 383)
Comply with the manufacturer's saf ety no tes on
th e stic ker of the emer gency spa rewheel and on
th e tyre in0ation compressor. #
Remo vethe stic ker with the label 80 km/h
from the tyre in0ation compressor housing
and a1x it tothe inst rument cluster within the
driver's /eld of vision. #
Remo vethe tyre in0ation compressor from the
st ow age space under the luggage compart-
ment 0oor . (/ page 356, 355) #
Pull /ller hose 1and plug 3out of the tyre
in0ation compressor housing. #
Insert plug 7of /ller hose 1inthe soc ket
on the tyre in0ation compressor and then turn
it until plug 7engages. #
Unscr ewthe cap from theva lve on the emer-
ge ncy spa rewheel. #
Screw union nut 2of /ller hose 1onto the
va lve. #
Make sure on and o. switch 4ofthe tyre
in0ation compressor is set to 00. #
Insert plug 3in a soc ket in your vehicle.
R Cigar ette lighter soc ket 390
390
Wheels and tyres

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences and0050
0050Solutions
Solutions
Place the key in the
marked space See Owner's
Manual *K
eydetection is malfunctioning. #
Change the location of theke y in theve hicle. #
Place theke y in the slot for starting the engine with theke y (/ page 170). Lights Lights
Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/conseq uences and
uences and0050
0050Solutions
Solutions
:
Left dipped beam (examp le) *T
he cor responding light source is defecti ve. #
Drive on carefull y. #
Consult a quali/ed specialist workshop immediatel y.
or #
Check whe ther you are permitted toreplace the light source yourself (/ page 148).
% LED light sources: the display message forth e cor responding light appears only when all the light-emitting diodes
in the light are faulty. Display message
s andwarning/indicator lamps
419
419