maintenance MERCEDES-BENZ B-CLASS HATCHBACK 2021 User Guide

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

This will contact
youto con/rm the appoint-
ment and if necessary consult about the
de tails.
% Ifyo u select LateraTerthe service message
appears, the message is hidden and reap-
pears at a later time.
Giving consent t
Giving consent t o dat
o data tr
a transf
ansf er dur
er dur ing a Mer
ing a Mer cedes
cedes
me call
me call
R R eq
eq uir
uir ements:
ements:
R There is an active Mercedes me call via the
multimedia system or the me button in the
ove rhead control panel (/ page 314).
% The prom pttocon/rm data transfer does not
appear in all count ries.
If th eAc cident and Breakdown Management ser v-
ices are not activated on Mercedes me, theDo
you want to transmit vehicle data and the vehi-
cle's position to the Mercedes-Benz Customer
Centre in order to improve the processing of
your request? message is shown. #
Select Yes.
Re leva nt identi/cation data is transmitted
automaticall y. More information on Mercedes me: https://
ww w.mercedes.me
T T r
ransf
ansf err
erred dat
ed dat a dur
a during a Mer
ing a Mer cedes me call
cedes me call
When you make a service call via Mercedes me,
data is transmitted. This enables targ eted advice
and a smoo thservice.
The following requ irements must be ful/lled for
th e transfer of the data:
R The vehicle is switched on.
R The required da tatransfer tech nology is sup-
por tedby the mobile phone network pr ovider.
R The quality of the mobile connection is su1-
cient.
Multi-s tage transfer depends on thefo llowing fac-
to rs:
R Reason forth e initiation of the call
R The available mobile phone transmission tech-
nology.
R The activated Mercedes me connect services.
R The service selected in thevo ice control sys-
te m. %
A prom ptfor consent tothe data transmission
only occurs if the cor responding Mercedes
me connect service is not activated.
Dat
Dat a tr
a transf
ansf er if Mer
er if Mer cedes me connect ser
cedes me connect ser vices
vices
ar
ar e no
e no t activ
t activ at
ated
ed
If no Mercedes me connect services are activated
and the data pr otection prom pthas been con-
/rmed thefo llowing data is transmitted:
R Vehicle identi/cation number
R Time of the call
R Reason forth e initiation of the call
R Con/ rmation of the data pr otection prompt
R Country indicator of theve hicle
R Set language forth e multimedia system
R Telephone number of the communication plat-
fo rm installed in theve hicle
If a call is made for a service appointment via the
service reminder, thefo llowing data is also trans-
mitted:
R Current mileage and maintenance data MBUX multimedia system
317
317

If a call is made aTer automatic accident or break-
down de
tection using the multimedia system, the
fo llowing data is also transmitted:
R Current mileage and maintenance data
R Current vehicle location
If Ac cident and Breakdown Management is called
via thevo ice control system and no service has
been activated, but the data pr otection query has
been con/ rmed, thefo llowing data can also be
called up from theve hicle bythe Mercedes-Benz
Customer Centre:
R Current vehicle location
If th e data pr otection prom pthas been rejec ted,
th efo llowing data is transmitted toenable targe-
te d advice and an e1cient service:
R Reason forth e initiation of the call
R Rejection of the data pr otection prompt
R Country indicator of theve hicle
R Set language forth e multimedia system
R Telephone number of the communication plat-
fo rm installed in theve hicle Dat
Dat a tr a transf
ansf er if Mer
er if Mer cedes me connect ser
cedes me connect ser vices
vices
ar
ar e activ
e activ at
ated
ed
Only if there specti veservice is activated will
additional incident-speci/c data be transmit ted in
th e second stage toenable an optimal service.
An ove rview of the data transmitted can be found
in there specti veterm s of use for Mercedes me
connect services. These can be obtained in the
Mercedes me por tal: https://
me.secure.mercedes-benz.com
Dat Dat a pr
a pr ocessing
ocessing
The data transmitted within the scope of the call
is dele ted from the processing system aTer the
call is /nished, in so far as this data is not being
used forot her activated Mercedes me connect
services.
The incident-speci/c data is processed and stored
in the Mercedes-Benz Customer Centre and, if
re qu ired toprocess the incident, forw arded tothe
service partner authorised bythe Mercedes-Benz
Customer Centre. Please take note of the data
pr otection information on the Mercedes me Inter-
net page https://www.mercedes.me or in there
corded message immediately aTer calling the
Mercedes-Benz Customer Centre.
% The recorded message is not available in
ev ery countr y. Mer Mer
cedes me connect
cedes me connect Inf
Inf
or
ormation on Mer
mation on Mer cedes me connect
cedes me connect
% Mercedes me connect or individual Mercedes
me connect services are not available in every
countr y.Find out at a Mercedes-Benz service
centre if these functions are available in your
countr y.
Mercedes me connect consists of multiple ser v-
ices.
Yo u can use thefo llowing services via the multi-
media system and theove rhead control panel, for
ex ample:
R Accident and Breakdown Management (me
button or situation-dependent display in the
multimedia system)
R Mercedes-Benz emer gency call system (auto-
matic eme rgency call and SOS button) 318 318
MBUX multimedia system

ASS
YS
ASS YST PL
T PL US ser
US ser vice int
vice int erv
erval display
al display F
F
unction of t
unction of t he ASSYS
he AS SYST PL
T PL US ser
US ser vice int
vice int erv
erval dis-
al dis-
play
play The ASS
YST PLUS service inter val display on the
inst rument display informs you of the time or dis-
ta nce remaining before the next service due date.
Yo u can hide this service display using the back
button Gonthe leT-hand side of the steering
wheel.
Depending on how theve hicle is used, the
ASS YST PLUS service inter val display may shor ten
th e service inter val, e.g. in thefo llowing cases:
R Mainly short-distance driving
R When the engine is oTen leT idling for long
periods
R Intheev ent of frequent cold start phases
R V
V ehicles wit ehicles wit h a diesel par
h a diesel par ticulat
ticulate
e/lt
/lt er:
er: inthe
ev ent of frequently inter rupted rege neration of
th e diesel particulate /lter
Mercedes-Benz recommends avoiding such oper-
ating conditions. Yo
u can obtain information concerning the servic-
ing of your vehicle from a quali/ed specialist
wo rkshop, e.g. a Mercedes-Benz service cent re. Displa
Displa
ying t
ying t he ser
he ser vice due date
vice due date On-board computer:
4 Service 5
ASSYST PLUS
The next service due date is displa yed. #
T
T o e
o e xit t
xit t he displa y:
he displ ay:press the back button
G onthe leT-hand side of the steering
wheel.
Bear in mind thefo llowing related topic:
R Operating the on-board computer
(/ page 282). Inf
Inf
or
ormation on r
mation on r egular maint
egular maint enance w
enance work
ork *
N
NOOTE
TE Premature wearthro ugh failure to
obser veservice due dates Main
tenance workwhich is not car ried out at
th eright time or inco mplete ly can lead to
increased wear and damage totheve hicle. #
Adhere tothe prescribed service inter-
va ls. #
Always ha vethe prescribed maintenance
wo rkcar ried out at a quali/ed specialist
wo rkshop. N
No
ot
tes on special ser
es on special ser vice r
vice req
equir
uir ements
ements The prescribed service inter
val is based on nor-
mal operation of theve hicle. Ha vethe mainte-
nance workcar ried out more oTen than prescri-
bed if operating conditions are di1cult or the
ve hicle is subject toincreased stress.
The ASS YST PLUS service inter val display is only
an aid. The driver of theve hicle bears responsibil-
ity as rega rdsto whe ther maintenance work
needs tobe per form ed more oTen than speci/ed
based on the actual operating conditions and/or
loads.
Examples of arduous operating conditions:
R Regular city driving with frequent intermediate
stops
R Mainly short-distance driving 336 336
Maintenance and care

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

Opening and closing t
Opening and closing t
he bonnet
he bonnet&
W
WARNING
ARNING Risk of accident due todriving
with the bonnet unloc ked
The bonnet may open and blo ckyour vie w. #
Neverre lease the bonnet when driving. #
Before every trip, ensure that the engine
bonnet is loc ked. &
W
WARNING
ARNING Risk of accident and inju ry
when opening and closing the bonnet
The bonnet may suddenly drop into the end
position.
There is a risk of injury for an yone in the
engine bonnet's range of mo vement. #
Do not open or close the bonnet if there
is a person in the bonnet's range of
mo vement. &
W WARNING
ARNING Risk of burns when opening the
bonnet
If yo u open the bonnet in theev ent of an over-
heated engine or /re in the engine compart-
ment, thefo llowing situations may occur:
R You may come into contact with hot gases.
R You may come into contact with other
escaping hot operating 0uids. #
Before opening the bonnet, allow the
engine tocool down. #
Intheev ent of a /re in the engine com-
partment, keep the bonnet closed and
call the /re service. &
W
WARNING
ARNING Risk of injury due tomoving
parts
Components in the engine compartment may
continue torun or start unexpectedly even
when the drive system is switched o..
Obser vethefo llowing if you must open the
bonnet: #
Switch o. theve hicle. #
Neverto uch the danger zones sur round-
ing moving components, e.g. thero tation
area of thefa n. #
Remo vejewe llery and watches. #
Keep items of clo thing and hair away
from moving pa rts. &
W
WARNING
ARNING Risk of injury from touching
components under voltage
The ignition system and the fuel injection sys-
te m operate at high voltage. You could receive
an elect ric shoc k. #
Neverto uch ignition system or fuel injec-
tion system components when theve hi-
cle is switched on. The live components include
thefo llowing, for
ex ample:
R Ignition coils
R Fuel injectors 338
338
Maintenance and care

R
Electric lines tothe ignition coils and the fuel
injectors &
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. &
W
W ARNING
ARNING Risk of injury from using the
windscreen wipers when the bonnet is
open
If th e windscreen wipers start moving when
th e bonnet is open, you could be trapped by
th e wiper linkage. #
Always switch o. the windscreen wipers
and theve hicle /r stifyo u need toopen
th e bonnet. Opening t
Opening t
he bonnet
he bonnet #
Torelease the bonnet, pull on handle 1. #
Push yellow handle 1onthe bonnet catch to
th e leT as far as it will go (palm down wards).
LiT the bonnet until it is automatically raised
by the pneumatic spring.
Closing t
Closing t he bonnet
he bonnet #
Lowe rth e bonnet and let it drop from a height
of appr oximately 20 cm. Maintenance and care
339
339

#
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

&
W
W ARNI NG
ARNI NGRisk of /re and injury from
engine oil
If engine oil comes into contact with hot com-
ponent parts in the engine compartment, it
may ignite. #
Make sure that no engine oil is spilled
next tothe /ller opening. #
Allow the engine tocool o. and thor-
oughly clean the engine oil from compo-
nent parts before starting theve hicle. *
N
NO OTE
TE Engine damage caused byan inco r-
re ct oil /lter, incor rect oil or additi ves #
Do not use engine oils or oil /lters which
do not cor respond tothe speci/cations
ex plicitly prescribed forth e service inter-
va ls. #
Follow the inst ructions on the service
inter val display forch anging the engine
oil and obser vethe prescribed change
inter vals. #
Do not use additives. *
N
NOOTE
TE Damage caused bytopping up too
much engine oil To
o much engine oil can damage the engine or
th e catalytic con verter. #
Have excess engine oil remo ved at a
qu ali/ed specialist workshop. %
Depending on driving st yle, theve hicle con-
sumes up to0.8 litre of oil per 1000 km. The
oil consum ption may be higher than this when
th eve hicle is new or if you frequently drive at
high engine speeds. #
Turn cap 1anti-clockwise and remo veit. #
Top up the engine oil. #
Replace cap 1and turn it clockwise until it
engages. #
Check the oil le vel again (/ page 340). Maintenance and care
341
341

Chec
Chec
king t
king t he coolant lev
he coolant lev el
el &
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. &
W
WARNING
ARNING Risk of scalding from hot cool-
ant
If yo u open the cap, you could be scalded. #
Let the mo tor cool down before opening
th e cap. #
When opening the cap, wear pr otective
glo ves and saf ety glasses. #
Open the cap slo wlytorelease pressure. #
Park theve hicle on a le vel sur face. #
Check the coolant temp erature display in the
inst rument cluster.
The coolant temp erature must be below 70°C. #
Slowly turn cap 1anti-clockwise torelease
ove rpressure. #
Continue turning cap 1anti-clockwise and
re mo veit. The coolant le
vel is cor rect in thefo llowing cases:
R Ifth e engine is cold, the coolant is up to
mar ker bar 2.
R Ifth e engine is warm,th e coolant is up to
1.5 cm overth e mar ker bar 2. #
If necessar y,top up with coolant that has
been appr ovedfo r Mercedes-Benz.
% Further information on coolant (/ page 404) T
T
opping up t
opping up t he windscr
he windscreen w
een washer syst
asher syst em
em &
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. 342
342
Maintenance and care