2021 MERCEDES-BENZ B-CLASS HATCHBACK brake

0073
Thechild restraint system must not be put
under strain bythe head restraint. Adjust the
head restraints as appropria te.
0073 Never place objects (e.g. cushions) under or
behind thech ild restraint system. &
W
WARNING
ARNING Risk of injur y or death due to
objects between the seat sur face and the
ch ild restraint system
Objects between the seat sur face and the
ch ild restraint system could a.ect the function
of the automatic front passenger airbag shut-
o.. #
Do not place any objects between the
seat sur face and thech ild restraint sys-
te m. #
Always make sure that thech ild restraint
system is co rrectly /t ted. #
Set the front passenger seat as far back as
possible and mo vethe seat into the highest
position if possible. #
Adjust the seat cushion inclination so that the
front ed geofthe seat cushion is in the highest position and
there ar edge of the seat cushion
is in the lo west position. #
Set the seat backrest tothe most vertical
position possible. #
Install thech ild restraint system.
The entire base of thech ild restraint system
must al ways rest on the sitting sur face of the
front passenger seat. #
Always make sure that the shoulder belt strap
is cor rectly routed from the seat belt outlet of
th eve hicle tothe shoulder belt guide on the
ch ild restraint system.
The shoulder belt strap must be routed for-
wa rds and down wards from the seat belt out-
let. #
If necessar y,adjust the front passenger seat
accordingl y. Child safe
Child safe
ty locks
ty loc ks A
A
ctiv
ctiv ating or deactiv
ating or deactiv ating t
ating the c
he child safe
hild safe ty loc
ty lock f
k for
or
t
t he r
he r ear doors
ear doors &
W
WARNING
ARNING Risk of accident and injury due
to leaving children unattended in theve hi-
cle
If ch ildren are leT unattended in theve hicle,
th ey could, in particular:
R open doors, thereby endangering other
persons or road users.
R get out and be struck byoncoming tra1c.
R operate vehicle equipment and become
trapped, forex ample.
In addition, thech ildren could also set the
ve hicle in motion by,fo rex ample:
R releasing the parking brake.
R changing the transmission position.
R starting theve hicle. #
Never lea vechildren unattended in the
ve hicle. 78
78
Occupant saf
ety

K
K
e
ey
y Ov
Ov
er
ervie
vie w of ke
w of key functions
y functions &
W
W ARNING
ARNING Risk of accident and inju rydue
to leaving children unattended in theve hi-
cle
If ch ildren are leT unattended in theve hicle,
th ey could, in particular:
R open doors, thereby endangering other
persons or road users.
R get out and be struck byoncoming tra1c.
R operate vehicle equipment and become
trapped, forex ample.
In addition, thech ildren could also set the
ve hicle in motion by,fo rex ample:
R releasing the parking brake.
R changing the transmission position.
R starting theve hicle. #
Never lea vechildren unattended in the
ve hicle. #
When leaving theve hicle, alw aysta ke the
ke y with you and lock theve hicle. #
Keep theve hicle key out of there ach of
ch ildren. *
N
NOOTE
TE Damage totheke y caused bymag-
netic /elds #
Keep theke yaw ay from strong magnetic
/elds. Ve
hicle key
1 Locks
2 Indicator lamp 3
Unloc ks
4 Opens/closes theta ilgate
% If indicator lamp 2does not light up aTer
pressing theÜ orß button, the battery
is we ak or possibly dischar ged. Re place the
battery as soon as possible.
Re place theke y battery (/ page 83).
The key loc ksand unloc ksthefo llowing compo-
nents:
R Doors
R Fuel /ller 0ap
R Soc ket 0ap (plug-in hybrid)
R Tailgate
If th eve hicle is not opened within appr oximately
40 seconds aTer unlocking, it loc ksagain. Anti-
th eT pr otection is primed again.
Do not keep theke yto get her with elect ronic devi-
ces or me tal objects. This can a.ect theke y's
functionalit y. Opening and closing
81 81

A
A
ctiv
ctiv ating/deactiv
ating/deactiv ating t
ating the hazar
he hazar d w
d war
arning lights
ning lights #
Press button 1.
The hazard warning lights will switch on automati-
cally if:
R the airbag has been deplo yed.
R theve hicle is heavily braked from a speed of
more than 70 km/h toa standstill. When
you pull away again, the hazard warning
light system will switch o. automatically at
appr oximately 10 km/h. You can also switch o.
th e hazard warning light system using button 1. A A
dap
dap tiv
tive functions, MUL
e functions, MUL TIBEAM LED
TIBEAM LED Int Int
ellig ellig ent Light Syst
ent Light Syst em function
em function
The MULTIBEAM LED headlamp s adapttothe
driving and weather situation and pr ovide exten-
ded functions for impr oved illumination of the
ro ad.
The system comprises thefo llowing functions:
R Active headlamps (/ page 141)
R Cornering light (/ page 142)
R Motorw ay mode (/ page 142)
R City lighting (/ page 142)
Syst
Syst em limits
em limits
R The system is active only when it is dar k.A
A
ctiv
ctiv e headlam
e headlamps function ps function R
The headlamps follow the steering mo ve-
ments.
R Releva nt areas are better illumina ted during a
journe y.
The functions are active when the high beam is
switched on. Light and sight
141
141

#
Neverto uch damaged components of
th e high-voltage on-board electrical sys-
te m. #
ATer an accident, do not touch any com-
ponents of the high-voltage on-board
electrical system. #
ATer an accident, ha vetheve hicle trans-
por tedawa y. #
Have the components of the high-voltage
on-board electrical system checked at a
qu ali/ed specialist workshop and
re placed if necessar y.R
R
eq
eq uir
uir ements:
ements:
Only disconnect the high-voltage on-board electri-
cal system manually in thefo llowing situations:
R The 0075 restraint system warning lamp lights
up in the Instrument Displa y,e.g. aTer an
accident.
R The vehicle is badly damaged, e.g. aTer an
accident, and there straint system co mpo-
nents ha venot been triggered. T
T
o oper
o oper at
ate t
e t he high-v
he high-v olt
oltag
age disconnect de
e disconnect de vice
vice #
Switch o. theve hicle. #
ShiT the transmission toposition 005D. #
Apply the electric parking brake. #
Secure theve hicle against rolling away (see
th eve hicle Owner's Manual). #
Open the bonnet. #
Press release tab1 inthe direction of the
ar ro w and pull it out. #
Pull high- voltage disconnect device 2inthe
direction of the ar row until it engages.
The high- voltage on-board electrical system is
switched o..
All workon thehy brid drive system (including
aTer disconnecting the high-voltage on-board
electrical system manually) may only be car ried
out byaqu ali/ed specialist workshop. Switc
Switc
hing on t
hing on t he pow
he power suppl
er suppl y or t
y or the v
he vehicle
ehicle &
W
WARNING
ARNING Risk of accident and injury due
to leaving children unattended in theve hi-
cle
If ch ildren are leT unattended in theve hicle,
th ey could, in particular:
R open doors, thereby endangering other
persons or road users.
R get out and be struck byoncoming tra1c. 168
168
Driving and parking

R
operate vehicle equipment and become
trapped, forex ample.
In addition, thech ildren could also set the
ve hicle in motion by,fo rex ample:
R releasing the parking brake.
R changing the transmission position.
R starting theve hicle. #
Never lea vechildren unattended in the
ve hicle. #
When leaving theve hicle, alw aysta ke the
ke y with you and lock theve hicle. #
Keep theve hicle key out of there ach of
ch ildren. R
R
eq
eq uir
uir ements:
ements:
R The key is in theve hicle and is recognised.
R V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: The
brake pedal is not depressed.
R V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: The clutch
pedal is not depressed. #
T To switc o switc h on t
h on the pow
he pow er supply
er supply :
:press button
1 once.
Yo u can, forex ample, activate the windscreen
wiper.
The po wer supply is switched o. again if thefo l-
lowing conditions are met:
R You open the driver's door.
R you press button 1twice more. #
T
To switc
o switc h on t
h on the v
he vehicle:
ehicle: press button 1
twice.
Indicator and warning lamps go on in the
inst rument cluster.
The vehicle is switched o. again if one of thefo l-
lowing conditions is met:
R V
V ehicles wit ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: You do
not start theve hicle within 15 minutes and the
transmission is in position 005Dorthe electric
parking brake is applied.
R V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: You do not
start theve hicle within 15 minutes and the
electric parking brake is applied.
R you press button 1once. S
S
t
tar
ar ting t
ting t he v
he vehicle
ehicle S S
t
tar
ar ting t
ting t he v
he vehicle wit
ehicle wit h t
h the st
he st ar
art/st
t/st op butt
op butt on
on &
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 Driving and parking
169
169

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 /re due to0ammable
material in the engine compartment or the
ex haust system
Flammable materials may ignite. #
Therefore, check regula rly th at there are
no 0ammable materials in the engine
compartment or on theex haust system. R
R
eq
eq uir
uir ements:
ements:
R The key is in theve hicle and is recognised. #
V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: Depress
th e clutch pedal. #
V Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: ShiT
th e transmission toposition 005Dor005C. #
Depress the brake pedal and press button 1
once. #
Ifth eve hicle does not start: switch o. non-
essential consumers and press but ton1
once. #
Ifth eve hicle still does not start and the dis-
play message Place the key in the marked
space See Owner's Manual appears inthe
inst rument displa y: starttheve hicle with the
ke y in the mar ked space (emer gency ope ra-
tion mode) (/ page 170).
% You can switch o. theve hicle while driving. To
do this, press button 1for about thre e sec-
onds or bypressing button 1thre e times
within thre e seconds. Be sure toobser vethe
saf ety no tes under "Driving tips"
(/ page 173).
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 wit
ehicle wit h t
h the ke
he key in t
y in t he mark
he mark ed
ed
space (emerg
space (emerg ency oper
ency oper ation mode)
ation mode)
If th eve hicle does not start and thePlace the
key in the marked space See Owner's Manual
message appears in the inst rument displa y,you can start
theve hicle in emer gency ope ration
mode. Mar
ked space (e xample with cup holder without
co ver) #
Open the co ver of the mar ked space 2if
necessar y. #
Make sure that the mar ked space 2is
em pty. 170 170
Driving and parking

#
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

R
The bonnet is closed.
R The doo rsare closed and loc ked.
R The windo wsand sliding sunroof are closed. #
Start theve hicle using the smartphone.
ATer every engine start, the engine runs for
te n minutes.
Yo u can car ryout a maximum of two consecutive
starting attem pts. You must start the engine with
th eke y before trying tostart theve hicle again
with the smartphone.
Yo u can switch o. theve hicle at any time as fol-
lo ws:
R Viath e Smartphone App
R By pressing theÜ orß button on the
key
% Further information can be found in the
smartphone app.
Secur
Secur ing t
ing the v
he v ehicle ag
ehicle ag ains
ainst st
t star
arting bef
ting bef or
ore car ry-
e car ry-
ing out maint
ing out maint enance or r
enance or repair w
epair wor
ork:
k: #
Switch on the hazard warning light system.
or #
Unlock the doors.
or #
Open a side window or the sliding sunroof. R
R
unning-in not
unning-in not es
es To
preser vethe engine during the /rst 1,500 km:
R Drive at varying road speeds and engine
speeds.
R Do not drive at speeds greater than
140 km/h.
R Drive theve hicle in drive prog ram A
or ;.
R ShiT tothe next highest gear at theve ry latest
when the needle reaches the last third before
th ere d area in there v counter.
R Do not shiT down manual lyin order tobrake.
R Avoid overstraining theve hicle, e.g. driving at
full thro ttle.
R V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: do not
depress the accelerator pedal be yond the
pressure point (kickdown). R
Only increase the engine speed gradually and
accelerate theve hicle tofull speed aTer
1,500 km.
This also applies when the engine or parts of the
driv etra in ha vebeen replaced.
Please also obser vethefo llowing running-in
no tes:
R In cer tain driving and driving saf ety sy stems,
th e sensors adjust automatically while a cer-
ta in distance is being driven aTer theve hicle
has been deli vered or aTer repairs. Full sys-
te m e.ectiveness is not reached until the end
of this teach-in process.
R Brakepads, brake disks and tyres that are
either new or ha vebeen replaced only achie ve
optimum braking e.ect and grip aTer se veral
hund red kilometres of driving. Compensate for
th ere duced braking e.ect byapplying greater
fo rc eto the brake pedal. 172
172
Driving and parking