warning MERCEDES-BENZ B-CLASS HATCHBACK 2021 Owner's Manual

In addition, a
warning tone may sound.
As soon as the driver and front passenger fasten
th eir seat belts, the seat belt warning goes out. F
F
unction of t
unction of t he r
he rear seat belt st
ear seat belt st atus display
atus displayThe
rear seat belt status displ ayis only available
fo r cer tain countries. When
theve hicle is switched on, there ar seat
belt status displ ayinforms youfo r a cer tain
amount of time which rear seat belt is not fas-
te ned. Yo
u can immediately dismiss there ar seat belt
status displ ayusing the back button on the leT-
hand side of the steering wheel (/ page 282).
If a vehicle occupant unfastens a seat belt in the
re ar while theve hicle is motion, there ar seat belt
status displ ayappears again.
In addition, a warning tone may sound. In this
case, there ar seat belt status displ aycannot be
hidden using the back button on the leT-hand side
of the steering wheel. Airbags
Airbags
Ov
Ov
er
ervie
vie w of airbags
w of airbags 1
Knee airbag
2 Driver's airbag
3 Front passenger airbag
4 Window airbag
5 Side airbag
The installation location of an airbag is identi/ed
by the AIRB AGsymbol.
When enabled, an airbag can pr ovide additional
pr otection forth ere specti ve vehicle occupant. 52
52
Occupant saf
ety

Po
tential pr otection pr ovided byeach airbag:
R Knee airbag: thigh, knee and lo wer leg
R Driver's airbag, front passenger airbag: head
and ribcage
R Window airbag: head
R Side airbag: ribcage and pelvis &
W
WARNING
ARNING Risk of inju ryor death if the co-
driver airbag is enabled
If th e co-driver airbag is enabled, a child on
th e co-driver seat may be struck bythe co-
driver airbag during an accident.
NEVER use a rear wa rd-facing child restraint
system on a seat wi than ENABLED FRONT
AIR BAG; DEATH or SERIOUS INJURY tothe
CHILD ca n occur. When /tting a
child restraint system tothe front
passenger seat, obser vetheve hicle-speci/c infor-
mation (/ page 77). Also, alw ays obser vethe
no tes on rear wa rd-facing or forw ard-facing child
re straint systems on the front passenger seat
(/ page 76). Inf
Inf or ormation on aut
mation on aut omatic fr
omatic front passeng
ont passeng er airbag
er airbag
shut
shut o.
o.
The front passenger airbag can only be deplo yed
in an accident if thePA SSENGER AIR BAG OFF
indicator la mpis o.. If the front passenger seat is
occupied, make sure, bo thbefore and during the
journe y,that the status of the front passenger air-
bag is cor rect (/ page 57).
* NO
NO TE
TEDeployment of components of the
re straint system when the front passenger
seat is unoccupied In an accident,
the components of the
re straint system ma y deployunnecessarily on
th e front passenger side if:
R There are heavy objects on the front
passenger seat.
R The seat belt tongue is engaged in the seat
belt buckle of the front passenger seat and
th e front passenger seat is unoccupied. #
Stow objects in a suitable place. #
Only one person should use each seat
belt at any one time. Depending on
the de tected accident situation, the
wind owairbag on the front passenger side may
deplo y.The airbag is deplo yedre ga rdless of
whe ther the front passenger seat is occupied. Pr
ot
Pr otection pro
ection pro vided b
vided by t
y the airbags
he airbags Depending on
the accident situation, an airbag
may supplement the pr otection o.ered bya cor-
re ctly fastened seat belt. &
W
WARNING
ARNING Risk of injur y or death due to
an inco rrect seat position
If yo u deviate from the cor rect seat position,
th e airbag cannot per form its intended pr otec-
tive function.
Each vehicle occupant must make sure of the
fo llowing:
R Fasten seat belts co rrectl y.Pregnant
wo men must take particular care toensure
th at the lap belt ne ver lies across the
abdomen. Occupant saf
ety
53 53

R
Adopt the cor rect seat position and keep
as farawa y as possible from the airbags.
R Obser vethefo llowing information. #
Always make sure that there are no
objects between the airbag and vehicle
occupant. To
avo idtherisks resulting from the deployment
of an airbag, each vehicle occupant must obser ve
th efo llowing information in particular:
R Before starting your journe y,adjust your seat
cor rectl y;the driver's seat and front
passenger seat should be mo ved as far back
as possible.
When doing so, alw ays obser vethe informa-
tion on the cor rect driver's seat position
(/ page 105).
R Only hold the steering wheel bythe steering
wheel rim. This allo ws the airbag tobe fully
deplo yed.
R Always lean against the seat backrest when
th eve hicle is in motion. Do not lean forw ards
or against the door or side windo w.You may ot
herwise be in the deployment area of the
airbags.
R The occupants must alw ayske ep their feet on
th e 0oor. Do not put your feet on the cockpit,
fo rex ample. Your feet may otherwise be in the
deployment area of the airbag.
R Ifch ildren are tr avelling in theve hicle, obser ve
th e additional no tes (/ page 62).
R Always st owand secure objects cor rectl y.
Objects in theve hicle interior may pr event an air-
bag from functioning cor rectl y.Each vehicle occu-
pant must alw ays make sure of thefo llowing in
particular:
R There are no people, animals or objects
between theve hicle occupants and an airbag.
R There are no objects between the seat, door
and door pillar (B-pillar).
R There are no hard objects, e.g. coat hangers,
hanging on thegr ab handles or coat hooks.
R There are no accessories, such as mobile navi-
gation devices, mobile phones or cup holders,
within the deployment area of an airbag, e.g. on
the cockpit, on the door, on the side win-
dow or on the side trim.
In addition, no connecting cables, tensioning
straps or retaining straps must be routed or
attached totheve hicle within the deployment
area of an airbag. Alw ays comply with the
accessory manu facturer's ins tallation inst ruc-
tions and, in particular, the no tes on suitable
places for installation.
R There are no heavy, sharp-edged or fragile
objects in the poc kets of your clo thing. Store
such objects in a suitable place. Limit Limit
ations of t
ations of t he prot
he pr otection pro
ection pro vided b
vided by airbags
y airbags &
W
WARNING
ARNING Risk of injury due tomodi/ca-
tions tothe co ver of an airbag
If yo u modify the co ver of an airbag or a1x
objects such as stic kers to it,the airbag may
no longer function cor rectl y. #
Never modify the co ver of an airbag and
do not a1x objects toit. 54
54
Occupant saf
ety

The installation location of an airbag is identi/ed
by the AIRB AGsymbol (/ page 52).
Objects in the deployment area of an airbag may
pr ev ent the airbag from functioning cor rectl y. &
W
WARNI NG
ARNI NGRisk of injury from objects in
th e deployment area of an airbag
Objects in the deployment area of an airbag
can hinder or pr event the cor rect deployment
of the airbag.
The airbag may then deploy in an uncontrolled
manner and may even cause additional inju-
ri es totheve hicle occupants bydeploying.
This may be the case in particular if the airbag
is integ rated into the seat. #
Always st owand secure objects cor-
re ctl y. #
Before commencing your journe y,make
sure that no objects are st owed in the
deployment area of an airbag. &
W
WARNING
ARNING Risk of inju ryor death due to
th e use of unsuitable seat co vers
Due tounsuitable seat co vers,th e airbags
cannot pr otect vehicle occupants as intended.
In addition, the operation of the automatic
front passenger airbag shuto. could be
re stric ted. #
You should only use seat co vers that
ha ve been appr oved forth e cor respond-
ing seats byMercedes-Benz. &
W WARNI NG
ARNI NGRisk of injury due tomalfunc-
tioning sensors in the door
The function of the airbags can be impaired
due tomodi/cations or incor rect wo rkper-
fo rm ed on the doors or door trim, or if the
doors are damaged. #
Never modify the doors or parts of the
doors. #
Always ha veworkon the doors or door
trim car ried out at a quali/ed specialist
wo rkshop. &
W
WARNING
ARNING Risk of injury due todeplo yed
airbag
A depl oyed airbag no longer o.ers any pr otec-
tion. #
Have theve hicle towe dto a quali/ed
specialist workshop in order tohave the
deplo yed airbag replaced. Ha
ve deplo yed airbags replaced immediatel y. S
S
t
tatus of t
atus of t he fr
he front passeng
ont passeng er fr
er front airbag
ont airbag F
F
unction of t
unction of t he aut
he automatic fr
omatic fr ont passeng
ont passeng er airbag
er airbag
shut
shut o.
o.
The automatic front passen ger airbag shuto. is
able todetect whe ther the front passenger seat is
occupied bya person or a child restraint system.
The front passenger airbag is enabled or disabled
acco rdingl y. Occupant saf
ety
55 55

&
W
WARNI NG
ARNI NGRisk of injury or dea thdue to
objects under the co-driver seat
Objects trapped under the co-driver seat can
inter fere with the function of the automatic
co-driver airbag shuto. or damage the system. #
Do not store any objects under the co-
driver seat. #
When the co-driver seat is occupied,
make sure that no objects are trapped
under the co-driver seat. When /tting a
child restraint system tothe front
passenger seat, obser vetheve hicle-speci/c infor-
mation (/ page 77). Also, alw ays obser vethe
no tes on rear wa rd-facing or forw ard-facing child
re straint systems on the front passenger seat
(/ page 76).
A person on the front passenger seat must
obser vethefo llowing information:
R Fasten seat belts co rrectly (/ page 48).
R Sit in an almost upright seat position with their
back against the seat backrest. R
Sit with their feet resting on the 0oor, if possi-
ble.
The front passenger airbag may otherwise be dis-
abled bymistake, forex ample, in thefo llowing sit-
uations:
R The front passenger transfers their weight by
supporting themsel ves on a vehicle armrest.
R The front passen ger sits in such a wayth at
th eir weight is raised from the seat sur face. &
W
WARNING
ARNING Risk of injury or death due to a
disabled front passenger airbag
The front passenger airbag is disabled when
th ePA SSENGER AIR BAG OFF indicator la mp
is lit.
A person in the front passenger seat could
th en, forex ample, come into contact with the
ve hicle interior, especially if the person is sit-
ting too close tothe cockpit. If
th e front passenger seat is occupied, alw ays
ensure that:
R the classi/cation of the person in the front
passenger seat is cor rect and the front
passenger airbag is enabled or disabled in
accordance with the person in the front
passenger seat.
R the front passenger seat has been mo ved
as far back as possible.
R the person is seated cor rectl y. #
Both before and during the journe y,
ensure that the status of the front
passenger airbag is cor rect. If
th e front passenger seat is occupied, the classi-
/cation of the person or child restraint system on
th e front passenger seat take s place aTer the
front passenger airbag shuto. self-test. The
PA SSENGER AIR BAG indicator la mps displ aythe
status of the front passenger airbag.
Alw ays obser vethe no tes on the function of the
PA SSENGER AIR BAG indicator la mps
( / page 57). 56 56
Occupant saf
ety

F
F
unction of t
unction of t he P
he PASSEN
ASSEN GER AIR BA
GER AIR BAG indicat
G indicat or
or
lam
lam ps
ps Ve
hicles without automatic front passen ger airbag
shuto. ha vea special stic ker a1xed tothe side of
th e cockpit on the front passenger side
(/ page 76). Self-t
Self-t
es
est of aut t of aut omatic fr
omatic fr ont passeng
ont passeng er airbag shut-
er airbag shut-
o.
o. When theve hicle is switched on, a self-test is per-
fo rm ed during which the two PASSENGER AIR
BAG ON and OFF indicator la mps light up simul ta-
neous ly.
The status of the front passenger airbag is dis-
pla yed via thePA SSENGER AIR BAG indicator
la mp s aTer the self-test:
R ON is lit:
ON is lit: the front passenger airbag may
deploy during an accident.
The indicator lamp goes out aTer 60 seconds.
R ON and OFF ar ON and OFF ar e no
e not lit:
t lit: the front passenger
airbag may deploy during an accident.
R OFF is lit:
OFF is lit: the front passenger airbag is disa-
bled. It will then not be deplo yed in theev ent
of an accident.
If th ePA SSENGER AIR BAG ON indicator la mpis
o., only thePA SSENGER AIR BAG OFF indicator
la mp shows th e status of the front passenger air-
bag. The PASSENGER AIR BAG OFF indicator la mp
may be lit continuously or be o.. If
th ePA SSENGER AIR BAG OFF indicator la mp
and the0075 restraint system warning lamp light
up simultaneousl y,the front passenger seat may
not be used. Also in this case, do not /t a child
re straint system tothe front passenger seat. Ha ve
th e automatic front passenger airbag shuto.
ch ecked and repaired immediately at a quali/ed
specialist workshop.
S
S t
tatus display
atus display
If th e front passenger seat is occupied, ensure,
bo th before and during the journe y,that the sta-
tus of the front passenger airbag is cor rect forthe
cur rent situation.
ATer
ATer /tting
/tting a r
a rearw
earw ar
ard-f
d-f acing c
acing c hild r
hild res
estrtraint sy
aint sy s-
s-
t
t em t
em t o t
o the fr
he fr ont passeng
ont passeng er seat
er seat::PA SSENGER AIR
BAG OFF must be lit continuous ly. &
W
WARNI NG
ARNI NGRisk of injury or dea thwhen
using a rear wa rd-facing child restraint sys-
te m while the front passenger airbag is
enabled
If yo u secure a child in a rear wa rd-facing child
re straint system on the front passenger seat
and thePA SSENGER AIR BAG OFF indicator Occupant sa
fety
57
57

lamp is o.,
the front passenger airbag can
deploy in theev ent of an accident.
The child could be struck bythe airbag. #
Always ensu rethat the front passenger
airbag is disabled. The PASSENGER AIR
BAG OFF indicator la mpmust be lit. #
NEVER use a rear wa rd-facing child
re straint system on a seat wi than ENA-
BLED FRONT AIR BAG. This can result in
th e DEATH of or SERIOUS INJURY tothe
CHILD. When /tting a
child restraint system tothe front
passenger seat, obser vetheve hicle-speci/c infor-
mation (/ page 76).
Depending on thech ild restraint system and the
stature of thech ild, thePA SSENGER AIR BAG OFF
indicator la mpmay be o.. In this case, do not /t
th ere ar wa rd-facing child restraint system tothe
front passenger seat.
Instead, /t there ar wa rd-facing child restraint sys-
te m to a suitable rear seat.
ATer
ATer /tting /tting a f
a forw
orw ar
ard-f
d-f acing c
acing c hild r
hild res
estr
traint sy
aint sy s-
s-
t
t em t
em t o t
o the fr
he fr ont passeng
ont passeng er seat
er seat::depending on thech
ild restraint system and the stature of thech ild,
PA SSENGER AIR BAG OFF may be lit continuous ly
or be o.. Alw ays obser vethefo llowing informa-
tion. &
W
WARNING
ARNING Risk of injury or death due to
incor rect positioning of thefo rw ard-facing
ch ild restraint system
If yo u secure a child in a forw ard-facing child
re straint system on the front passenger seat
th at is positioned too close tothe cockpit, in
th eeve nt of an accident, thech ild could:
R come into contact with parts of theve hi-
cle's interior if thePA SSENGER AIR BAG
OFF indicator la mpis lit, forex ample
R be st ruck bythe airbag if thePA SSENGER
AIR BAG OFF indicator la mpis o. #
Always mo vethe front passenger seat as
fa r back as possible and fully retract the
seat cushion length adjustment. While
doing so, alw ays make sure that the
shoulder belt st rap is cor rectly routed
from the seat belt outlet of theve hicle to
th e shoulder belt guide on thech ild re
straint system. The shoulder belt strap
must be routed forw ards and down wards
from the seat belt outlet. If necessar y,
adjust the front passenger seat accord-
ingl y. #
Always comply with thech ild restraint
system manufactu rer's installation
inst ructions. When /tting a
child restraint system tothe front
passenger seat, obser vetheve hicle-speci/c infor-
mation (/ page 76).
If a per If a per son is sitting on t
son is sitting on t he fr
he front passeng
ont passeng er seat
er seat::
PA SSENGER AIR BAG OFF may be lit continuous ly
or be o., depending on the person's stature.
A person on the front passenger seat must alw ays
obser vethefo llowing information:
R Ifth e front passenger seat is occupied byan
adult or a person with a stature cor responding
to that of an adult, thePA SSENGER AIR BAG
OFF indicator la mpmust be o.. This indicates
th at the front passenger airbag is enabled.
If th ePA SSENGER AIR BAG OFF indicator
la mp is lit continuousl y,an adult or person 58
58
Occupant saf
ety

with a build cor
responding tothat of an adult
must not use the front passenger seat.
Instead, they should use a rear seat.
R Ifth e front passenger seat is occupied by a
person of smaller stature (e.g. a teenager or
small adult), thePA SSENGER AIR BAG OFF
indicator la mpis either lit continuously or
re mains o., depending on the classi/cation.
- Ifth ePA SSENGER AIR BAG OFF indicator
la mp is o.: mo vethe front passenger seat
as far back as possible, or the person of
smaller stature should use a rear seat.
- Ifth ePA SSENGER AIR BAG OFF indicator
la mp is lit continuousl y:the person of
smaller stature should not use the front
passenger seat. &
W
WARNING
ARNING Risk of injury or death when
th ePA SSENGER AIR BAG OFF indicator
la mp is lit
If th ePA SSENGER AIR BAG OFF indicator
la mp remains lit aTer the self-test, the front
passenger airbag is disabled. If
th e front passenger seat is occupied, alw ays
ensure that:
R The classi/cation of the person in the front
passenger seat is cor rect and the front
passenger airbag is enabled or disabled in
accordance with the person in the front
passenger seat.
R The person is seated proper lywith a cor-
re ctly fastened seat belt.
R The front passenger seat has been mo ved
as far back as possible. Be sure
toalso obser vethefo llowing fur ther rela-
te d subjects:
R Child restraint system on the front passenger
seat (/ page 76)
R Suitable positioning of thech ild restraint sys-
te m (/ page 66) PRE-S PRE-S
AFE
AFE®
®
syst
syst em
em F
F
unction of PRE-S
unction of PRE-S AFE
AFE®
®
(anticipat
(anticipat or
ory occupant
y occupant
pr ot
pr otection)
ection) PRE-SAFE
®
is able todetect cer tain critical driv-
ing situations and implement pre-em ptive meas-
ures toprotect theve hicle occupants.
PRE-SAFE ®
can implement thefo llowing meas-
ures independently of each other:
R Tightening the seat belts on the driver's seat
and front passenger seat.
R Closing the side windo ws.
R V
V ehicles wit
ehicles wit h sliding sunr
h sliding sunr oof:
oof:closing the slid-
ing sunroof.
R V
Vehicles wit
ehicles wit h memor
h memory function:
y function: movingthe
front passenger seat toa more favo urable seat
position.
R PRE-SAFE ®
Sound: pr ovided that the multime-
dia system is switched on, generating a brief
noise signal tostimula tethe innate pr otective
mechanism of a person's hearing. Occupant saf
ety
59
59

*
N
NO
OTE
TE Damage caused byobjects in the
fo ot we ll or behind the seat The automatic adjustment of
the seat position
may result in damage tothe seat and/or the
object. #
Stow objects in a suitable place. R
R
e
ev
ver
er sing t
sing t he PRE-S
he PRE-S AFE
AFE®
®
syst
syst em measur
em measur es
es If an accident did not occur,
the pre-em ptive
measures that we re ta ken are reve rsed.
Yo u will need toper form certain settings yourself. #
Ifth e seat belt pre-tensioning is not reduced,
mo vethe seat backrest back slightl y.
The locking mechanism releases. F
F
unction of PRE-S
unction of PRE-S AFE
AFE ®
®
PL
PL US (anticipat
US (anticipat or
ory occu-
y occu-
pant pr ot
pant pr otection plus)
ection plus) PRE-SAFE
®
PLUS can de tect cer tain impacts, par-
ticular lyan imminent rear impact, and take pre-
em ptive measures toprotect theve hicle occu- pants. These measures cann
otnecessarily pre-
ve nt an imminent impact.
PRE-SAFE ®
PLUS can implement thefo llowing
measures independently of each other:
R Tightening the seat belts on the driver's seat
and front passenger seat.
R Activating there ar hazard warning lights at a
higher 0ashing frequency.
R Increasing brake pressure when theve hicle is
stationar y.This brake application is cancelled
automatically when theve hicle pulls away.
If an accident did not occur, the pre-em ptive
measures that we re ta ken are reve rsed.
Syst
Syst em limits
em limits
The system will not initiate any action in thefo l-
lowing situations:
R when reve rsing
or
R when theve hicle is towing a trailer and there
is a risk of a rear impact The system will not initiate any braking application
in thefo llowing situations:
R whilst driving
or
R when entering or exiting a parking space while
using Active Parking Assist A A
ut
ut omatic measur
omatic measur es
esaTer
aTer an accident
an accident
Depending on the type and se verity of the acci-
dent, and depending on theve hicle's equipment,
th efo llowing measures can be implemented, for
ex ample:
R automatic braking (post-collision brake)
R activating the hazard warning lights
R triggering an automatic emer gency call
(/ page 325)
R switching o. the engine
To start theve hicle again, switch theve hicle
o. and on once more (/ page 169). Depend-
ing on the type and se verity of the accident,
yo u may no longer be able tostart theve hicle.
R switching o. the fuel supply 60
60
Occupant saf
ety

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