2021 MERCEDES-BENZ B-CLASS HATCHBACK engine

#
Select Maximum ,8 amps or6 amps .
When the battery is charge d, thech arging cur-
re nt is limi tedto the selected amperage.
% For saf etyre asons, only use thech arging
cable supplied with theve hicle or an original
Mercedes-Benz charging cable. Mercedes-
Benz thoroughly tests these original charging
cables forth eir suitability forth e high-voltage
ch arging of your vehicle. Pur chase these parts
from your Mercedes-Benz Service Centre and
obtain advice there.
A
A ctiv
ctiv ating or deactiv
ating or deactiv ating r
ating rout
oute-based oper
e-based oper ating
ating
mode s
mode str trat
at egy
egy #
Select Electric in city .
Depending on the pr evious status, the func-
tion is activated or deactivated. Calling up t Calling up t
he ener
he energy
gy0ow
0ow display
display Multimedia system:
4 © 5
EQ #
Select Energy flow.
The visualisation of the energy 0ow in theve hi-
cle is displ ayed. In addition
tothe energy 0o w,information on the
status of thehy brid system and the cur rent state
of charge ofthe high-voltage battery is also dis-
pla yed. F F
unctions of t
unctions of t he ener
he energy
gy0ow
0ow display
display 1
State of charge ofthe high-voltage battery
2 Combustion engine
3 Energy 0ow
4 High-voltage battery
5 Status of thero ute-based operating-mode
strategy (/ page 181) The active components of
thehy brid system are
highlighted in the energy 0ow displa y.The energy
0ow between the individual components is shown
in colour.
The energy 0ow is shown in di.erent colours
depending on the operating status:
R Whit
Whit e: e:constant energy 0ow
R R
Red:
ed: high energy 0ow (boost e.ect)
R Gr
Green:
een: low- emission energy 0ow in the case of
re cuperation, elect ric mode and when charg-
ing the high-voltage battery N
N
a
avig
vig ation
ation N
No
ot
tes on na
es on na vig
vigation
ation R
R
out
out e guidance wit
e guidance wit h augment
h augmented r
ed reality
eality &
W
WARNING
ARNING Risk of accident and injury as a
re sult of distraction, inco rrect depiction or
wrong interpr etation of the display
The camera image of the augmented reality
displ ayis not suitable as a guide for driving. 302
302
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