2021 MERCEDES-BENZ B-CLASS HATCHBACK light

R
R
es
estr traint syst
aint syst em functionality
em functionality When
theve hicle is switched on, a self-test is per-
fo rm ed, during which the0075 restraint system
wa rning lamp lights up. It goes out no later than a
few seconds aTer theve hicle is star ted. The com-
ponents of there straint system are then func-
tional. Malfunctioning r
Malfunctioning r
es
estr traint syst
aint syst em
em A malfunction has occur
red in there straint sys-
te m if:
R the0075 restraint system warning lamp does
not light up when theve hicle is switched on
R the0075 restraint system warning lamp lights
up continuously or repeatedly during a journey
All v
All v ehicles, ex
ehicles, excep
cep t plug-in h
t plug-in h ybr
ybrid:
id: &
W
WARNING
ARNING Risk of injury due tomalfunc-
tions in there straint system
Co mp onents in there straint system ma y be
acti vated unintentionally or not deploy as
intended in an accident. #
Have there straint system checked and
re paired immediately at a quali/ed spe-
cialist workshop. Plug-in h
Plug-in h
ybr
ybrid:
id: &
D
DAN
AN GER
GER Risk of fatal injuries due to
re straint system malfunctions
Co mp onents in there straint system ma y be
acti vated unintentionally or not deploy as plan-
ned in an accident. In theeve nt of an acci-
dent, the high-voltage on-board electrical sys-
te m may not be deactivated as intended.
Yo u may su.er an electric shock if youto uch
th e damaged components of the high-voltage
on-board electrical system. #
Have there straint system checked and
re paired immediately at a quali/ed spe-
cialist workshop. #
ATer an accident, switch o. theve hicle
immediatel y. F
F
unction of t
unction of t he r
he res
estrtraint syst
aint syst em in an accident
em in an accident How
there straint system works depends on the
se verity of the impact de tected and the apparent
type of accident:
R Frontal impact
R Rear impact
R Side impact
R Only for cer tain countries: rollo ver
The activation thre sholds forth e components of
th ere straint system are de term ined based on the
ev aluation of the sensor values measured at vari-
ous points in theve hicle. This process is pre-e mp-
tive in nature. The triggering/deployment of the
components of there straint system must take
place in good time at the start of the collision.
Fa ctors which can only be seen and measured
aTer a collision has occur red cannot play a deci-
sive role in airbag deployment. Nor do they pro-
vide an indication of airbag deployment.
The vehicle may be deformed signi/cantly without
an airbag being deplo yed. This is the case if only
parts which are relatively easily deformed are
a.ec tedand thera te of vehicle deceleration is Occupant saf
ety
47 47

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

*
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

R
v
vehicles wit
ehicles wit h h
h hybr
ybr id dr
id dr iv
ive:
e: switching o. the
hy brid system and high-voltage on-board elec-
trical system
R unlocking theve hicle doors
R lowe ring the side windo ws
R displaying the emer gency guide in the multi-
media system display
R switching on the interior lighting
F
F unction of t
unction of t he pos
he post-collision brt-collision br ake
ake
Depending on the accident situation, the post-col-
lision brake can minimise the se verity of a fur ther
collision or evenavo id it.
If an accident is de tected, the post-collision brake
can implement automatic braking. When theve hi-
cle has come toa standstill, the electric parking
brake is automatically applied.
The driver can cancel automatic braking bytaking
th efo llowing actions:
R braking more strongly than automatic braking
R fully depressing the accelerator pedal with
fo rce Saf Saf
el
ely tr
y tr anspor
anspor ting c
ting childr
hildren in t
en in t he v
he vehicle
ehicle Alw
ay
Alw ays observ
s observ e when c
e when c hildr
hildren ar
en ar e trav
e tr avelling in t
elling in t he
he
v
v ehicle
ehicle %
Also strictly obser vethe saf ety no tesfo rthe
speci/c situation. In this wa yyo u can recog-
nise po tential risks and avoid dangers if chil-
dren are tr avelling in theve hicle
(/ page 62).
Be dilig
Be dilig ent
ent
Bear in mind that negligence when securing a
ch ild in thech ild restraint system ma y haveseri-
ous conse quences. Alw ays be dili gent in securing
a ch ild carefully before every journe y.
Ne ver allow babies and children totrave l sitting
on the lap of ano ther vehicle occupant.
To impr oveprotection forch ildren younger than
12 years old or under 1.50 m in height,
Mercedes-Benz recommends you obser vethefo l-
lowing information:
R Always secure thech ild in a child restraint sys-
te m suitable forth is Mercedes-Benz vehicle.
R The child restraint system must be appropria te
to the age, weight and size of thech ild. R
The vehicle seat must be suitable for /tting a
ch ild restraint system (/ page 66).
Ac cident statistics show that children secured on
th ere ar seats are generally sa ferth an children
secured on the front seats. Forth is reason,
Mercedes-Benz st rongly advises that you /t a
ch ild restraint system toare ar seat.
The g The g ener
eneric t
ic ter
erm c
m c hild r
hild r es
estr
traint syst
aint syst em
em
The generic term child restraint system is used in
th is Owner's Manual. A child restraint system is,
fo rex ample:
R a baby car seat
R are ar wa rd-facing child seat
R afo rw ard-facing child seat
R ach ild booster seat with a backrest and seat
belt guide
Mercedes-Benz recommends using a child
booster seat with a backrest.
The child restraint system must be appropria te to
th e age, weight and size of thech ild. Occupant saf
ety
61 61

Onl
Onl
y use c
y use c hild r
hild res
estrtraint syst
aint syst ems whic
ems whic h ar
h are in
e in
pr
pr oper w
oper w or
orking condition
king condition &
W
WARNING
ARNING Risk of injury or death caused
by the use of damaged child restraint sys-
te ms
Child restraint systems or their reta ining sys-
te ms that ha vebeen subjected tostress in an
accident ma y not be able toper form their
intended pr otective function.
It may be the case that thech ild cannot be
proper ly restrained. #
Always immediately replace child
re straint systems that ha vebeen dam-
aged or in volved in an accident. #
Have the securing systems forth ech ild
re straint systems checked at a quali/ed
specialist workshop before ins talling a
ch ild restraint system again. A
A
v
void dir
oid dir ect sunlight
ect sunlight &
W
WARNING
ARNING Risk of bu rns when thech ild
seat is exposed todirect sunlight
If th ech ild restraint system is exposed to
direct sunlight or heat, parts could heat up.
Children could su.er burns from these parts,
particular lyon me tallic parts of thech ild
re straint system. #
Always make sure that thech ild restraint
system is not exposed todirect sunlight. #
Protect thech ild restraint system wi th a
blank et,fo rex ample. #
Ifth ech ild restraint system has been
ex posed todirect sunlight, allow it to
cool before securing a child into it. #
Never lea vechildren unattended in the
ve hicle. Observ Observ
e when st
e when st opping or par
opping or par king
king &
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. #
When leaving theve hicle, alw aysta ke the
ke y with you and lock theve hicle. 64
64
Occupant saf
ety

F
F
itting t
itting t he ISOFIX or i‑Size c
he ISOFIX or i‑Size c hild r
hild res
estrtraint syst
aint syst em
em
on t
on t he
heleT
leT and r
and r ight r
ight r ear seats
ear seats &
W
WARNING
ARNING Risk of accident if there ar
ben chseat, rear seat and seat backrest
are not engaged
The rear ben chseat, rear seat and seat bac k-
re st ma yfo ld forw ards, even while theve hicle
is in motion.
R As a result, theve hicle occupant will be
pressed into the seat belt with increased
fo rc e. The seat belt will not be able topro-
te ct as intended and could cause addi-
tional injur y.
R Objects or loads in the boot or load com-
partment cannot be restrained bythe seat
backrest. #
Make sure that there ar ben chseat, the
re ar seat and the seat backrest are
engaged before every trip. If
th ere ar seat backrest is not engaged and
loc ked in place, there d lock veri/cation indicator
will be visible. &
W
WARNING
ARNING Risk of inju ryor death if the
permissible gross mass of thech ild and
ch ild restraint system toge ther is excee-
ded.
To o much load may be placed on the ISOFIX
or i‑Size child restraint systems and thech ild
may not be restrained co rrectly in theev ent of
an accident, forex ample. #
Ifth ech ild and thech ild restraint system
to get her weigh more than 33 kg, only
use an ISOFIX or i‑Size child restraint
system wi thwhich thech ild is secured
with theve hicle seat belt. #
Also secure thech ild restraint system
wi th th eTo pTe ther belt, if available. Alw
ays comply with the information about the
mass of thech ild restraint system:
R inthe manufacturer's installation and operat-
ing inst ructions forth ech ild restraint system
used
R on a label on thech ild restraint system, if
present Re
gula rly ch eck that the permissible gross mass
of thech ild and child restraint system is still com-
plied wi th.
When /tting a child restraint system, obse rvethe
fo llowing:
0073 Always obser vethe cor rect use of the seats
and consider their suitability for attaching a
ch ild restraint system.
ISOFIX child seat securing system
(/ page 68)
or
i‑Size child seat securing system
(/ page 69)
0073 Always comply with the manufacturer's
installation and operating instructions forthe
ch ild restraint system used.
0073 Makesure that thech ild's feet do not touch
th e front seat. If necessar y,mo vethe front
seat slightly forw ards.
® When /tting an ISOFIX child restraint sys-
te m, also obser vethefo llowing:
0073 When using a bab
When using a bab y car seat in w y car seat in weightgr
eight group
oup
0/0+ and a r
0/0+ and a r earw
earwar
ard-f
d-f acing c
acing c hild r
hild res
estrtraint
aint 70
70
Occupant saf
ety

te
ct as intended and could cause addi-
tional injur y.
R Objects or loads in the boot or load com-
partment cannot be restrained bythe seat
backrest. #
Make sure that there ar ben chseat, the
re ar seat and the seat backrest are
engaged before every trip. If
th ere ar seat backrest is not engaged and
loc ked in place, there d lock veri/cation indicator
will be visible.
When
When /tting /tting a belt-secur
a belt-secur ed c
ed child r
hild r es
estr
traint sy st
aint syst em,
em,
obse rv
observ e t
e the f
he f ollo
ollowing:
wing:
0073 Always comply with the manufacturer's
installation and operating inst ructions forthe
ch ild restraint system used.
0073 For a child restraint system in the "Universal"
or "Semi-Universal" categor y,make sure that
th e system has been appr ovedfo rth eve hicle
seat. Obser
vethe no tes under "Suitability of seats
fo r attaching belt-secured child restraint sys-
te ms" (/ page 73).
0073 When using a w
When using a w eight cat
eight categor
egory 0/0+ bab
y 0/0+ bab y
y
car seat and a w
car seat and a w eight cat
eight categor
egory I r
y I rearw
earw ar
ard-
d-
f
f acing c
acing c hild r
hild res
estrtraint syst
aint syst em on a r
em on a r ear seat:
ear seat:
adjust the front seat so that the seat does
not touch thech ild restraint system.
0073 When using a w
When using a w eight cat
eight categor
egory I f
y I forw
orw ar
ar d-
d-
f
f acing c
acing c hild r
hild res
estr
traint sy st
aint syst em:
em:remo vethe
head restraint from there specti veseat, if
possible.
ATer thech ild restraint system has been
re mo ved, replace the head restraint immedi-
atel y and adjust all head restraints co rrectl y.
0073 The backrest of thefo rw ard-facing child
re straint system must, as far as possible, be
re sting on the seat backrest of there ar seat.
0073 Ifth e head restraint of thech ild seat cannot
be fully extended when it is installed in the
ve hicle, this will result in restrictions on the
maximum size setting forch ild restraint sys-
te ms in weight category II or III. Contact with
thero of when the head
re straint is ful lyex tended and loc ked in place
will not result in any restrictions on use.
0073 Thechild restraint system must not be put
under strain between thero of and the seat
cushion and/or be /t tedfacing the wrong
direction. Where possible, adjust the seat
cushion inclination accordingl y.
0073 Thechild restraint system must not be put
under strain bythe head restraint. Adjust the
head restraints as appropria te.
0073 Make sure that thech ild's feet do not touch
th e front seat. If necessar y,mo vethe front
seat slightly forw ards. #
Installth ech ild restraint system.
The entire base of thech ild restraint system
must al ways rest on the seat sur face of the
re ar 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
fo rw ard from the seat belt outlet. Occupant saf
ety
75 75

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