MERCEDES-BENZ B-CLASS HATCHBACK 2021 Workshop Manual

not high. Con
versely, an airbag may be depl oyed
ev en though theve hicle su.ers only minor defor-
mation. If very rigid vehicle parts such as longitu-
dinal membe rsare hit, this may result in su1-
ciently high le vels of vehicle deceleration.
Depending on the de tected deployment situation,
th e components of there straint system can be
acti vated or deplo yed independently of each
ot her:
R Seat belt tensioner: frontal impact, rear
impact, side impact, rollo ver 1
R Driver's airbag, front passenger airbag: frontal
impact
R Knee airbag: frontal impact
R Side airbag: side impact
R Window airbag: side impact, rollo ver 1
, frontal
impact
1) Only for cer tain countries.
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 thejourne
y,that the status of the front passenger air-
bag is cor rect (/ page 57). &
W
WARNING
ARNING Risk of burns from hot airbag
components
The airbag parts are hot aTer an airbag has
been deplo yed. #
Do not touch the airbag parts. #
Have a depl oyed airbag replaced at a
qu ali/ed specialist workshop as soon as
possible. Mercedes-Benz
recommends that you ha vethe
ve hicle towe dto aqu ali/ed specialist workshop
aTer an accident. Take this into account, particu-
lar lyif a seat belt tensioner is triggered or an air-
bag deplo yed.
If th e seat belt tensioners are triggered or an air-
bag is deplo yed, you will hear a bang, and a small
amount of powder may also be released:
R The bang will not generally a.ect your hearing.
R Ingeneral, the powder released is not hazard-
ous tohealth but may cause short- term breathing di1culties
topersons su.ering from
asthma or other pulmonary conditions.
Pr ov ided it is safe todo so, lea vetheve hicle
immediately or open the window in order to
pr ev ent breathing di1culties. Seat belts
Seat belts
Pr
ot
Pr otection pro
ection pro vided b
vided by t
y the seat belt
he seat belt Alw
aysfa sten your seat belt cor rectly before
starting a journe y.A seat belt can only pr ovide
th e best le vel of pr otection if it is worncor rectl y. &
W
WARNI NG
ARNI NGRisk of injury or dea thdue to
incor rectly fastened seat belt
If th e seat belt is not worncor rectl y,it cannot
per form its intended pr otective function.
In addition, an incor rectly fastened seat belt
can also cause injuries, forex ample, in the
ev ent of an accident or when braking or
ch anging direction suddenl y.48
48
Occupant saf
ety

#
Always ensu rethat all vehicle occupants
ha ve their seat belts fastened co rrectly
and are sitting proper ly.Alw
ays obser vethe inst ructions about the cor rect
driver's seat position and adjusting the seat
(/ page 105).
In order forth e cor rectly wornseat belt toprov ide
th e intended le vel of pr otection, each vehicle
occupant must obser vethefo llowing information:
R The seat belt must not be twisted and must /t
tightly and snugly across the body.
R The seat belt must be routed across the
cent reofthe shoulder and as low down across
th e hips as possible.
R The shoulder section of the seat belt should
not touch your neck nor be routed under your
arm or behind your bac k.
R Avoid wearing bulky clo thing, e.g. a winter
coat.
R Push the lap belt down as far as possible
across your hips and pull tight with the shoul-
der section of the belt. Neverro ute the lap
belt across your abdomen. Pregnant
women must also take particular
care with this.
R Neverro ute the seat belt across sharp, poin-
te d, abrasive or fragile objects.
R Only one person should use each seat belt at
any one time.
R Never secure objects with a seat belt if the
seat belt is also being used byone of theve hi-
cle's occupants.
Also ensu rethat no objects, e.g. a cushion,
are ever placed between a person and the
seat.
If ch ildren are tr avelling in theve hicle, be sure to
obser vethe inst ructions and saf ety no tes on
"Child ren in theve hicle" (/ page 62).
Alw ays obser vethe inst ructions for loading the
ve hicle when securing objects, lug gage or loads
(/ page 118). Limit Limit
ations of t
ations of t he prot
he pr otection pro
ection pro vided b
vided by t
y the seat
he seat
belt
belt &
W
WARNING
ARNING Risk of injury or death due to
incor rect seat position
The seat belt will not o.er the intended le vel
of pr otection if you ha venot mo vedth e seat
backrest toan almost vertical position.
In particular, you may slip under the seatbelt
and injure yourself. #
Adjust the seat proper lybefore begin-
ning your journe y. #
Always ensu rethat the seat backrest is
in an almost vertical position and that
th e shoulder section of your seat belt is
ro uted across the centre of your shoul-
der. Occupant saf
ety
49
49

&
W
WARNI NG
ARNI NGRisk of injury or dea thwhen
additional restraint systems are not used
fo r persons with a smaller stature
Pe rsons under 1.50 m tall cannot wearthe
seat belt cor rectly without a suitable addi-
tional restraint system. #
Always secure persons under 1.50 m tall
in a suitable restraint system. &
W
WARNING
ARNING Risk of injur y or death due to
damaged or modi/ed seat belts
Seat belts cannot pr ovide pr otection in thefo l-
lowing situations:
R the seat belt is damaged, has been modi-
/ed, is extremely dirty, blea ched or dyed
R the seat belt buckle is damaged or
ex tremely dirty
R modi/cations ha vebeen made tothe seat
belt tensioner, seat belt anchorage or seat
belt retractor
Seat belts may sustain non-visible damage in
an accident, e.g. due toglass splinters. Modi/ed or damaged seat belts could
tear or
fa il in theev ent of an accident, forex ample.
Modi/ed seat belt tensioners could acciden-
ta lly trigger or failto function as intended. #
Never modify the seat belt system, for
ex ample the seat belt, seat belt buckle,
seat belt tensioner, seat belt anchorage
and seat belt retractor. #
Make sure that the seat belts are undam-
aged, not wornand clean. #
Always ha vethe seat belts checked
immediately aTer an accident at a quali-
/ed specialist workshop. Mercedes-Benz
recommends that you use seat
belts which ha vebeen appr ovedfo ryo ur vehicle
by Mercedes-Benz. &
W
WARNI NG
ARNI NGRisk of injury or dea thfrom
deplo yedpy rotech nic seat belt tensioners
Pyro tech nic seat belt tensioners that ha ve
been deplo yed are no longer operational and
are unable toper form their intended pr otec-
tive function. #
Therefore, ha vedeplo yedpy rotech nic
seat belt tensioners immedia tely
re placed at a quali/ed specialist work-
shop. Mercedes-Benz
recommends that you ha vethe
ve hicle towe dto aqu ali/ed specialist workshop
aTer an accident.
* N
NOOTE
TE Damage caused bytrapping the
seat belt If an unused seat belt is not fully
retracted, it
may become trapped in the door or in the seat
mechanism. #
Always ensu rethat an unused seat belt
is fully retracted. F
F
ast
ast ening seat belts
ening seat belts If
th e seat belt is pulled quickly or sharpl y,the
seat belt retractor loc ks. The seat belt strap can-
not be pulled out any fur ther. 50
50
Occupant saf
ety

#
Always engage seat belt tongue 2ofthe seat
belt into seat belt buckle 1ofthe cor re-
sponding seat.
% A seat belt can only pr ovide the best le vel of
pr otection if it is worncor rectl y.Obser vethe
no tes on fastening the seat belt (/ page 48).*
N
NOOTE
TE Deployment of components of the
re straint system when the front passenger
seat is unoccupied and a seat belt is
buckled When
the front passenger seat is unoccupied
and the seat belt tongue of the seat belt is
engaged in the seat belt buckle, components
of there straint system ma y deployunnecessa-
ri ly on the front passenger side, e.g. the seat
belt tensioner. #
Only buckle the seat belts as intended. %
Obser vethe no tes on st owage areas
(/ page 118).
Information on /tting a child restraint system
and on children tr avelling in theve hicle can
be found in the "Children in theve hicle" sec-
tion (/ page 66). Seat belt adjus Seat belt adjustment function
tment function V
V
ehicles wit
ehicles wit h PRE-S
h PRE-SAFE
AFE®
®
:
:aTer a front seat belt
has been fastened, the automatic seat belt adjust- ment may apply a cer
tain tightening forc e. Do not
hold the seat belt tightly while it is adjusting.
Yo u can activate and deactivate the seat belt
adjustment function using the multimedia system
(/ page 51). A
A
ctiv
ctiv ating/deactiv
ating/deactiv ating seat belt adjus
ating seat belt adjustment via tment via
t
t he multimedia syst
he multimedia syst em
em Multimedia system:
4 © 5
Settings 5
Vehicle #
Activate or deactivate Belt adjustment. R
R
eleasing seat belts
eleasing seat belts #
Press there lease button in the seat belt
buckle and guide the seat belt back with the
seat belt tongue. Seat belt w
Seat belt w
ar
arning function f
ning function f or t
or the dr
he dr iv
iver and fr
er and fr ont
ont
passeng
passeng er
er The
00E9 seat belt warning lamp in the Instru-
ment Display is a reminder that all vehicle occu-
pants must weartheir seat belts cor rectl y. Occupant saf
ety
51
51

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