2021 MERCEDES-BENZ B-CLASS HATCHBACK service

Observ
Observ
e law
e laws and leg
s and leg al r
al req
equir
uir ements
ements
Alw ays obser vethe legal requ irements when
using a child restraint system in theve hicle.
Make sure that thech ild restraint system is
appro ved in accordance with theva lid test speci/-
ca tions and guidelines. Further information can
be obtained at a quali/ed specialist workshop.
Mercedes-Benz recommends that you use a
Mercedes-Benz Service Centre forth is purpose.
Onl
Onl y use appr ov
y use appr oved ced c hild r
hild r es
estrtraint syst
aint syst ems
ems
Only child restraint systems that meet thefo llo w-
ing UNECE standards are permitted for use in the
ve hicle:
R UN-R44
R UN-R129 (i-Size child restraint systems)
In fo rm ation on child restraint system appro val
categories and de tails on the appr oval label on
th ech ild restraint system (/ page 66). Det
Det
ecting r
ecting r isk
isks,av
s, avoiding dangoiding dang er
er Secur Secur
ing syst ing syst ems f
ems for c
or child r
hild r es
estrtraint syst
aint syst ems in
ems in
t
t he v
he v ehicle
ehicle
Only use thefo llowing securing systems forch ild
re straint systems:
R the ISOFIX or i-Size securing rings
R theve hicle's seat belt system
R theTo pTe ther anchorages
Fi tting an ISOFIX or an i-Size child restraint sys-
te m is prefer red.
Simply attaching tothe securing rings on theve hi-
cle can reduce therisk of /tting thech ild restraint
system incor rectl y.
When securing a child with the integ rated seat
belt of the ISOFIX or i-Size child restraint system,
al wa ys comply with the permissible gross weight
fo rth ech ild and child restraint system
(/ page 70).
A
A dv
dv ant
ant ag
age of a r
e of a r earw
earwar
ard-f
d-f acing c
acing c hild r
hild res
estrtraint sy
aint sy s-
s-
t
t em
em
It is preferable totransport a baby or a small child
in a suitable rear wa rd-facing child restraint sys- te
m. In this case, thech ild sits in the opposite
direction tothe direction of tr avel and faces bac k-
wa rds.
Babies and small children ha vecomparatively
we ak neck muscles in relation tothe size and
we ight of their head. The risk of injury tothe cer-
vical spine during an accident can be reduced in a
re ar wa rd-facing child restraint system.
Alw ay
Alw ays secur
s secur e a c
e a child r
hild r es
estr
traint syst
aint syst em corr
em correctly
ectly &
W
WARNING
ARNING Risk of injury or death due to
incor rect ins tallation of thech ild restraint
system
The child can then not be pr otected or
re strained as intended. #
Be su retocomply with the manufactur-
er's installation inst ructions forth ech ild
re straint system and its co rrect use. #
Make sure that the entire base of the
ch ild restraint system al ways rests on
th e sitting sur face of the seat. 62
62
Occupant saf
ety

#
Keep theve hicle key out of there ach of
ch ildren. &
W
W ARNING
ARNING Risk offatal injury due toexpo-
sure toextreme heat or cold in theve hicle
If persons, particular lych ildren, are subjected
to prolonged exposure tointense heat or cold,
th ere is a risk of se vere injury or even death. #
Never lea vepersons, particular lych il-
dren, unattended in theve hicle. Ov
Ov
er
ervie
vie w of r
w of r ecommended c
ecommended c hild r
hild res
estr
traint syst
aint syst ems
ems %
Further information on the cor rect child
re straint system can be ob tained at a quali-
/ed specialist workshop. Mercedes-Benz rec-
ommends that you use a Mercedes-Benz
Service Centre forth is purpose. Secur
Secur ing wit
ing wit h ISOFIX
h ISOFIX
W
W eight cat
eight cat egor
egory 0+ (up t
y 0+ (up t o 13 k
o 13 kg and up to
g and up to
appro
appro x. 15 mont
x. 15 mont hs)
hs) T
T
ype
ype 1
1
B
BAB
AB Y S
Y S AFE plus
AFE plus
Size catego ry E
Appro valE 1 04 301 146
Order number 2
B6 6 86 8224
1 Manufacturer: Britax Römer .2 With colour code 9H95. W
W
eight cat
eight cat egor
egory I (9 t
y I (9 t o 18 k
o 18 kg and fr g and fr om appro
om appro x-
x-
imat
imat el
ely 9 mont
y 9 mont hs t
hs to 4 y
o 4 y ear
ears)
s) T
T
ype
ype 1
1
DUO plus
DUO plus
Size categor yB1
Appro valE 1 04 301 133
Order number 2
A 000 970 43 02
1 Manufacturer: Britax Römer .2 With colour code 9H95. Secur
Secur
ing wit
ing wit h t
h the v
he v ehicle seat belt
ehicle seat belt
W
W eight cat
eight cat egor
egory 0 (up t
y 0 (up t o 10 k
o 10 kg and approg and appro ximat
ximat ely
ely
6 mont
6 mont hs) and w
hs) and w eight cat
eight categor
egory 0+ (up t
y 0+ (up t o 13 kg
o 13 kg
and appro
and appro ximat
ximatel
ely 15 mont
y 15 mont hs)
hs) T
T
ype
ype 1
1
B
BAB
AB Y S
Y S AFE plus II
AFE plus II
Appr oval E1 04 301 146
Order number 2
A 000 970 38 02
1 Manufactu rer: Britax Römer .2 With colour code 9H95. W
W
eight cat
eight cat egor
egory I (9 t
y I (9 t o 18 k
o 18 kg and fr g and fr om appro
om appro x-
x-
imat
imat el
ely 9 mont
y 9 mont hs t
hs to 4 y
o 4 y ear
ear s)
s) T
T
ype
ype 1
1
DUO plus
DUO plus
Appr oval E1 04 301 133
Order number 2
A 000 970 43 02
1 Manufactu rer: Britax Römer .2 With colour code 9H95. Occupant saf
ety
65
65

#
Remo vetheke y1 from theke yring. #
Place theke y1 inthe mar ked space 2on
th e symbol 3.
The vehicle will start aTer a short time.
When youre mo vetheke y1 from the mar ked
space 2,theve hicle can be driven. For fur-
th er engine starts ho wever,theke y1 must
be located in the mar ked space 2onthe
symbol 3during the entire journe y. #
Have theke y1 checked at a quali/ed spe-
cialist workshop.
If t
If t he v
he v ehicle does no
ehicle does no t st
t st art:
art: #
Place theke y1 inthe mar ked space 2and
lea veitth ere. #
V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: Depress
th e clutch pedal. #
Depress the brake pedal and start theve hicle
using the start/s top button.
% You can switch on the po wer supply or the
ve hicle with the start/s top button. Obser
veany information rega rding display mes-
sages that can be displ ayed on the inst rument
displa y. S
S
t
tar
ar ting t
ting t he v
he vehicle via R
ehicle via R emot
emote Online Ser
e Online Ser vices
vices Cooling or heating t
Cooling or heating t
he v
he vehicle int
ehicle int er
erior bef
ior bef ore
ore
st
st ar
ar ting t
ting t he jour
he jour ney
ney
Ensu rethefo llowing before starting the engine:
R The legal stipulations in the area where your
ve hicle is par ked allow engine starting via
smartphone.
R It is safe tostart and runth e engine where
yo ur vehicle is par ked.
R The fuel tank is su1cient lyfull.
R The star ter battery is su1ciently charge d.
Char
Char ging t
ging t he st
he start
arter batt
er batt er
ery bef
y bef or
ore st
e st ar
arting t
ting t he
he
jour
jour ney
ney
Yo u can receive a message on your smartphone
when the state of charge ofthe star ter battery is
lo w. You can then start theve hicle with the smart-
phone tocharge the batter y.The vehicle is auto-
matically switched o. aTer ten minutes. Ensure
thefo llowing before starting the engine:
R The legal stipulations in the area where your
ve hicle is par ked allow engine starting via
smartphone.
R It is safe tostart and runth e engine where
yo ur vehicle is par ked.
R The fuel tank is su1cient lyfull.
S
S t
tar
ar ting t
ting t he v
he vehicle (R
ehicle (R emot
emot e Online)
e Online) &
W
WARNING
ARNING Risk of crushing or entrapment
due tounintentional starting of the engine
Limbs could be crushed or trapped if the
engine is star ted unintentionally during service
or maintenance work. #
Always secure the engine against unin-
te ntional starting before ca rrying out
main tenance or repair work. R
R
eq
eq uir
uir ements:
ements:
R Park position 005Dis selected.
R The anti-theT alarm system is not activated.
R The hazard warning light system is switched
o.. Driving and parking
171
171

The lettering in
the segment will light up brightl y,
th e outer edge will light up and the segment will
/ll up when thefo llowing driving style is adop ted:
R 1 Steady speed
R 2 Gentle deceleration and rolling
R 3 Moderate acceleration
The lettering in the segment will be grey ,th e outer
edge will be dark and the segment will em pty
when thefo llowing driving style is adop ted:
R 1 Fluctuations in speed
R 2 Heavy braking
R 3 Sporty acceleration
The ECO display will show you when you ha ve
driven economicall y:
R The thre e segments will /ll up comple tely at
th e same time
R The edges around all thre e segments will light
up
The additional range achie ved as a result of your
driving style in comparison with a driver with a
ve ry sporty driving st yle will be shown in thecent
reof display 4. Therange displa yed does
not indicate a /xed reduction in consum ption. R R
eg
eg ener
ener ativ
ative br
e br ak
ake syst
e syst em (plug-in h
em (plug-in h ybr
ybrid)
id) F F
unction of t unction of t he r
he recuper
ecuper ativ
ative br
e br ak
ake syst
e syst em
em
Depending on the selected recuperation le vel,the
electric mo tor is operated as an alternator when
in ove rrun mode and during braking in order to
ch arge the high-voltage battery while driving. As
soon as youre lease the accelerator pedal when
th eve hicle is in motion, recuperation in overrun
mode is initiated.
The higher there cuperation, the more sharply the
ve hicle is braked when coasting and the more
electrical energy is fed into the high-voltage bat-
te ry.
The rege nerative brake system has thefo llowing
ch aracteristics:
R supports braking with elect ronically cont rolled
brake force boosting
R con verts th e kinetic energy of theve hicle into
elect ric energy %
Ifyo u brake hard, the mechanical brake is
also used. This means that the maximum
re cuperative energy cann otbe reco vered. The
more you drive and brake in an anticipatory
manner, the more e1cient lyenergy can be
re cuperated.
Syst
Syst em limits em limits
The braking e.ect of the electric mo tor during
re cuperation in overrun mode may be reduced or
may not be available at all in thefo llowing situa-
tions:
R when the high-voltage battery charge level
increases
R ifth e high-voltage battery is not yet at a nor-
mal operating temp erature
R when driving at speeds close tozero
R in transmission position 005C
R during and aTer ESP ®
inter venes
In these cases, the desired deceleration is set by
th e brake control system. Also brake with the
service brake if necessar y.178
178
Driving and parking

Obser
vethe no tes on operating 0uids
(/ page 396).
Ad Blue ®
is available here:
R AdBlue ®
can be topped up byfast se rvice at a
qu ali/ed specialist workshop, e.g. a
Mercedes-Benz Se rvice Centre.
R AdBlue ®
is available at many /lling stations
from AdBlue ®
/lling pumps.
R Alternati vely,Ad Blue ®
is available at quali/ed
specialist workshops, e.g. Mercedes-Benz
Se rvice Centres, and at many /lling stations in
Ad Blue ®
re/ll canis ters or AdBlue ®
re/ll bot-
tles.
% Ensure the connection between there /ll con-
ta iner and vehicle /ller neck does not drip.
T
T opping up A
opping up A dBlue
dBlue®
®
* NO
NOTE
TEEngine damage due toAd Blue ®
being in the fuel #
AdBlue ®
must not be used to/ll the fuel
ta nk. #
Only use AdBlue ®
to /ll theAd Blue ®
ta nk. #
Do not over/ll theAd Blue ®
tank. *
N
NOOTE
TE Contamination of theve hicle inte-
ri or due toAd Blue ®
lea kage #
ATer topping up, carefully close the
Ad Blue ®
re/ll con tainer. #
Avoid car rying AdBlue ®
re/ll con tainers
permanently in theve hicle. R
R
eq
eq uir
uir ements:
ements:
R The vehicle is unloc ked.
The following message s appear in order in the
Instrument Displ aywhen theAd Blue ®
tank
re qu ires topping up:
R Refill AdBlue See Owner’s Manual The
Ad Blue ®
leve l has fallen below there ser ve
ra nge. Top up with at least 5 l of AdBlue ®
.
R Top up AdBlue Emergency op. in XXX miles
See Owner's Manual The lowAdBlue ®
level
will lead tolimited per form ance aTer the re
maining distance displa yed has been driven.
To p up with at least 5 l of AdBlue ®
.
R XX,X l Top up AdBlue Emer. op.: max. XXX
km/h Start not poss. in XXX km The low
Ad Blue ®
leve l will lead tolimited per form ance
from the speed displa yed. ATer there maining
distance displa yed has been co vered, it will no
longer be possible tostart theve hicle. Top up
with at least the amount of AdBlue ®
displa yed.
R XX,X l Top up AdBlue Switch on ignition, wait
60 sec. or eng. start not poss. TheAdBlue ®
ta nk is em pty. Yo u can no longer start the
ve hicle. Top up with at least the amount of
Ad Blue ®
displa yed. Switch on theve hicle and
wa itfor appr oximately 60 seconds. Start the
ve hicle.
Yo u can see theAd Blue ®
range and le vel in the
Service menu in the Instrument Displa y.
% The AdBlue ®
range sh own depends strongly
on the driving style and operating conditions.
The actual range can therefore deviate from
th e calculated range. 196
196
Driving and parking

It is
recommended that youch arge the high-volt-
age battery at a wallbox or charging station due to
th e impr ovedch arging per form ance and better
ch arging e1ciency o.ered.
S
S t
to
o wing t
wing t he c
he char
harging cable
ging cable
Alw ays st owtheve hicle charging cable in the
ch arging cable bag pr ovided and secure it in the
boot or load compartment of your vehicle.
Otherwise, thech arging cable is not su1ciently
secured.
Syst
Syst em limits em limits
The po wer output of the high-voltage battery may
be impaired bythefo llowing:
R High or low outside temp eratures
R Electrical auxiliary consumers in theve hicle
being switched on, e.g. operating the air con-
ditioning system
R Extended periods without charging
The charging time of the high-voltage battery may
be increased bythefo llowing:
R High or low outside temp eratures
R Extended periods without charging R
The maximum available charge cur rent of the
ch arging facility
R The charging cur rent set (mode 2) in the multi-
media system (/ page 301) N
No
ot
tes on c
es on c har
harging t
ging t he high-v
he high-v olt
oltag
age batt
e batt er
ery at t
y at t he
he
mains soc ke
mains soc ket (mode 2)
t (mode 2) &
D
DAN
AN GER
GER Risk of fatal injury from incor-
re ctly ins talled component parts
Connecting thech arging cable toa mains
soc ket using incor rectly ins talled component
parts could cause a /re or an electric shoc k,
fo rex ample. #
Only connect thech arging cable to a
mains soc ketth at:
R Has been proper lyinstalled and
R Has been inspected byaqu ali/ed elect ri-
cian #
For saf etyre asons, only use thech arging
cable supplied with theve hicle or an
original Mercedes-Benz charging cable. #
Purchase these parts at a Mercedes-
Benz Service Centre and obtain advice
th ere.
Mercedes-Benz thoroughly tests these original
ch arging cables forth eir suitability for high-
vo ltage charging of your vehicle. #
Never use a damaged charging cable. #
Do not use:
R Extension cables
R Extension reels
R Multiple soc kets #
Never use soc ket ada pters toconnect
th ech arging cable tothe mains soc ket.
The only exception being if the adap ter
has been tested and appro vedby the
manufacturer forch arging the high-volt-
age battery of an electric vehicle. #
Obser vethe saf ety no tes in the operat-
ing inst ructions forth e soc ket ada pter. Only
thefo llowing charging cables may be used:
R The charging cable supplied with theve hicle. 200 200
Driving and parking

higher
than the amount of energy actually absor-
bed bythe high-voltage batter y.This is there sult
of di.erent le vels of charging losses and is descri-
bed as rech arge e1ciency. Charging losses occur,
fo rex ample, due toheat that builds up when
ch arging or from auxiliary consumers that are
switched on. Further information on rech arge e1-
ciency can be obtained at a quali/ed specialist
wo rkshop. Se
Se
tting t
tting t he maximum per
he maximum per missible c
missible c har
harging cur-
ging cur-
r
r ent f
ent f or c
or char
harging at a mains soc ket
ging at a mains soc ket *
N
NO
OTE
TE Overloading the mains soc ket due
to excessive charging cur rent If
th ech arging cur rent is too high, the fuse
could be tripped or theex tern al mains supply
could overheat. #
Make sure that theex tern al mains supply
has been designed tohandle the set
ch arging cur rent. #
If necessar y,reduce the set charging
cur rent or use a di.erent mains soc ket. #
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 suitabil-
ity for high-voltage charging of your vehi-
cle. Pur chase these parts at a Mercedes-
Benz Service Centre and obtain advice
th ere. #
Check the setting of the maximum
ch arge cur rent using thech arging capa-
city shown in the Instrument Displa y. Before
charging at a mains soc ket, ha vethe maxi-
mum permissible charging cur rent forth ere leva nt
mains soc ket or the building inspected byaqu ali-
/ed elect rician. The charging cable supplied is set
to a countr y-speci/c maximum charging cur rent
va lue. When charging abroad, the maximum value
may exceed the permitted value forth at countr y.
When abroad, obser vethe count ry-speci/c la ws
when charging. If you ha vequestions concerning
setting thech arging cur rent or if there is a mal-
function, please contact a quali/ed specialist
wo rkshop. #
Set the maximum permissible charging cur-
re nt in the multimedia system menu
(/ page 301).
If th eex act value of the maximum permissible
ch arging cur rent cannot be set, select the next
smaller adjustable value.
% Ifth eve hicle requ ires more time than usual to
ch arge the high-voltage batter y,ch eck the
maximum charging cur rent settings in the
multimedia system menu. Ov Ov
er
er vie
vie w of t
w of t he c
he char
harging cable contr
ging cable contr ol panel
ol panel The
charging cable cont rol panel sho ws the cur-
re nt status of thech arging process. Driving and parking
203
203

*
N
NO
OTE
TE Damage totheve hicle due toitro ll-
ing away #
Always secure theve hicle against rolling
awa y. #
Bring theve hicle toa standstill bypressing the
brake pedal. #
Ongradients, turn the front wheels so that the
ve hicle will rollto wa rdsth eke rb if it starts
moving. #
Apply the electric parking brake. #
V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: Engage
/rst 0047orreve rsege ar 005E. #
V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: Engage
transmission position 005Din a stationary vehi-
cle with the brake pedal applied
(/ page 188). #
Switch o. theve hicle bypressing the1 but-
to n. #
Release the service brake slo wly. #
Get out of theve hicle and lock it.
% When you park theve hicle, you can still oper-
ate the side windo wsand the panoramic slid-
ing sunroof for appr oximately four minutes if
th e driver's door is closed. Gar
Gar
ag
age door opener
e door opener Pr
Pr
ogr
ogr amming butt
amming butt ons f
ons for t
or the g
he g ar
arag
ag e door opener
e door opener &
D
DAN
AN GER
GER Risk of fatal injuries caused by
ex haust gases
Combustion engines emit poisonous exhaust
ga ses such as carbon monoxide. Inhaling
th ese exhaust gases is hazardous tohealth
and leads topoisoning. #
Never lea vetheve hicle or, if present, the
stationa ryheater running in an enclosed
space without su1cient ventilation. &
W
WARNI NG
ARNI NGRisk of injury bybecoming
trapped when opening and closing a
ga rage door
When you operate or prog ram a garage door
with an integ ratedga rage door opener, per-
sons can become trapped or struck bythe
ga rage door if they stand wi thin its range of
mo vement. 216 216
Driving and parking