2018 MERCEDES-BENZ A-CLASS HATCHBACK Owners Manual

Re
stra int sy stem Pr
otection bythere stra int sy stem The
restra int sy stem includes thefo llowing com‐
ponents:
R Seat belt sy stem
R Airbags
R Child restra int sy stem
R Child seat securing sy stem
The restra int sy stem can reduce therisk of vehi‐
cle occupants coming into contact with parts of
th eve hicle's interior in theeve nt of an accident.
The restra int sy stem can also reduce thefo rc es
to which vehicle occupants are subjected in the
eve nt of an accident.
Only a seat belt which is worncor rectly can pro‐
vide the intended le vel of pr otection. Depending
on the de tected accident situation, seat belt ten‐
sioners and/or airbags supplement a cor rectly
wo rnseat belt. Seat belt tensioners and/or air‐
bags are not depl oyed in everyaccident. Fo
rth ere stra int sy stem toprov ide its full pr otec‐
tion, each occupant must obser vethefo llowing:
R Fasten the seat belt cor rectl y.
R Be in an almost up right position with their
back against the seat backrest.
R Sit with their feet resting on thefloor, if pos‐
sible.
R Alw ays secure persons under 1.50 m tall in
an additional restra int sy stem suitable for
Mercedes-Benz vehicles.
Ho wever,no sy stem available today can com‐
ple tely eliminate injuries and fata lities in every
accident situation. In particular, the seat belt
and airbag generally do not pr otect against
objects penetrating theve hicle from the outside.
The risk of an injury resulting from airbag
deployment also cannot be ruled out entirel y. Re
duced restra int sy stem pr otection &
WARNING Risk of inju ryor death from
modifications tothere stra int sy stem
The restra int sy stem can no longer function
cor rectly af ter alterations ha vebeen made.
The restra int sy stem may then not pr otect
th eve hicle occupants as intended byfailing
in an accident or triggering unexpec tedly, for
ex ample #
Never alter the parts of there stra int
sy stem. #
Neverta mp er with the wiring or any
electronic component parts or their
software. If it is necessary
tomodify theve hicle toaccom‐
modate a person with disabilities, con tact a
qu alified specialist workshop.
Mercedes-Benz recommends that you use driv‐
ing aids which ha vebeen appr ovedfo ryo ur vehi‐
cle byMercedes-Benz. 30
Occupant saf ety

Re
stra int sy stem functionality When
the ignition is switched on, a self-test is
per form ed, during which the6 restra int sys‐
te m wa rning lamp lights up. It goes out no later
th an a few seconds af terth eve hicle is star ted.
The components of there stra int sy stem are then
functional. Malfunctioning
restra int sy stem A malfunction has occur
red in there stra int sys‐
te m if:
R the6 restra int sy stem warning lamp does
not light up when the ignition is switched on
R the6 restra int sy stem warning lamp
lights up continuously or repeatedly during a
journey &
WARNING Risk of inju ryor fata l injury
due toa malfunction in there stra int sys‐
tem
If th ere stra int sy stem is malfunctioning,
re stra int sy stem components may be trig‐ ge
red unintentionally or might not be trig‐
ge red at all in theev ent of an accident. This
may af fect the seat belt tensioner or airbag,
fo rex ample. #
Have there stra int sy stem checked and
re paired immediately at a qualified spe‐
cialist workshop. Fu
nction of there stra int sy stem in an acci‐
dent How
there stra int sy stem works is de term ined by
th e se verity of the impact de tected and the type
of accident anticipated:
R Frontal impact
R Rear impact
R Side impact
R Onlyfor cer tain countries: rollo ver
The activation thre sholds forth e components of
th ere stra int sy stem are de term ined based on
th eev aluation of the sensor values measured at
va rious points in theve hicle. This process is pre-
em ptive in nature. The triggering/deployment of th
e components of there stra int sy stem must
ta ke place in good time at thest art of the colli‐
sion.
Fa ctors whi chcan only be seen and measu red
af te r a collision has occur red cann otplay a deci‐
sive role in airbag deployment, nor do they pro‐
vide an indication of airbag deployment.
The vehicle may be deformed significantly with‐
out an airbag being deplo yed. This is the case if
only parts which are relatively easily deformed
are af fected and thera te ofvehicle deceleration
is not high. Con versely, an airbag may be
deplo yedev en though theve hicle suf fers only
minor deformation. If very rigid vehicle parts
such as longitudinal members are hit, forex am‐
ple, this may result in suf ficiently high le vels of
ve hicle deceleration. Occupant saf
ety31

The co
mponents of there stra int sy stem can
be activated or deplo yed independently of
each other: Component De
tected deploy‐
ment situation
Seat belt tensioner sFrontal impact, rear
impact, side impact,
ro llo ver 1) Driver's airbag, front
passenger front air‐
bag
Fr
ontal impact Knee airbag
Frontal impact Side impact airbag Side impact
Wi ndow airba gS ide impact,roll‐
over 1)
, frontal impact 1)
Only for cer tain countries.
The front passen ger front airbag can only be
depl oyed in an accident if thePA SSENGER AIR
BA G OFF indicator lamp is off. If the front
passenger seat is occupied, make sure, bo thbefore and during
the journe y,that thest atus of
th e front passenger front airbag is cor rect
(→ page 41). &
WARNING Rick of burns from hot airbag
components
The airbag parts are hot af ter an airbag has
been depl oyed. #
Do not touch the airbag parts. #
Have a deplo yed airbag replaced at a
qu alified specialist workshop as soon
as possible. Mercedes-Benz
recommends that you ha vethe
ve hicle towe dto aqu alified specialist workshop
af te r an accident. Take this into account, partic‐
ularly if a seat belt tensioner is trig gered or an
airbag deplo yed.
If th e seat belt tensioners are trig gered 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 af fect your hear‐
ing. R
Ingeneral, the powder released is not haz‐
ardous tohealth but may cause short-term
breathing dif ficulties topersons suf fering
from as thma or other pulmonary conditions.
Pr ov ided it is safe todo so, lea vetheve hicle
immediately or open the window in order to
pr eve nt brea thing dif ficulties. Seat belts
Pr
otection pr ovided bythe seat belt Alw
aysfast enyour seat belt co rrectly before
st arting a journe y.A seat belt can only pr ovide
th e best le vel of pr otection if it is worncor rectly. &
WARNING Risk of inju ryor death due to
incor rectly fastened seat belt
If th e seat belt is not worncor rectly, it can‐
not 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 sudden ly.32
Occupant saf ety

#
Alw ays ensure that all vehicle occu‐
pants ha vetheir seat belts fastened
cor rectly and are sitting prope rly. Alw
ays obser vethe instructions about the cor‐
re ct driver's seat position and adjusting the seat
(→ page 88).
In order forth e cor rectly wornseat belt topro‐
vide the intended le vel of pr otection, each vehi‐
cle occupant must obser vethefo llowing infor‐
mation:
R The seat belt must not be twis ted and must
fi t tightly and snu gly across the body.
R The seat belt must be routed across the
centre of the shoulder and as low down
across the hips as possible.
R The shoulder section of the seat belt should
not touch your ne cknor be routed under
yo ur 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. Ne verro ute the lap
belt across your abdomen.
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. Ne ver allow babies and chil‐
dren totrave l sitting on the lap of ano ther
ve hicle occupant.
R Never secure objects with a seat belt if the
seat belt is also being used byone of the
ve hicle's occupants. Alw ays obser vethe
instructions for loading theve hicle when
securing objects, luggage or loads
(→ page 101).
Also ensu rethat no objects, e.g. a cushion,
are ever placed between a person and the
seat.
If ch ildren are tra velling in theve hicle, be sure to
obser vethe instructions and saf ety no tes on
"Children in theve hicle" (→ page 46). Re
duced seat belt pr otection &
WARNING Risk of inju ryor death due to
incor rect seat position
The seat belt does not of ferth e intended
le ve l of pr otection if you ha venot mo vedthe
seat backrest toan almost vertical position.
When braking or in theeve nt of an accident,
yo u could slide underneath the seat belt and
sus tain abdominal or neck injuries, forex am‐
ple. #
Adjust the seat proper lybefore begin‐
ning your journe y. #
Alw ays ensure that the seat backrest is
in an almost vertical position and that
th e shoulder section of your seat belt is
ro uted across the cent reofyour shoul‐
der. Occupant saf
ety33

&
WARNING Risk of inju ryor death when
additional restra int sy stems are not used
fo r persons with a smaller build
Pe rsons under 1.50 m tall cannot wearthe
seat belt cor rectly wi thout a suitable addi‐
tional restra int sy stem.
If th e seat belt is not worncor rectly, it can‐
not 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 sudden ly.#
Alw ays secure persons under 1.50 m
ta ll in a suitable restra int sy stem. &
WARNING Risk of inju ryor death due to
damaged or modified seat belts
Seat belts cann otprov ide pr otection in the
fo llowing situations:
R Ifth e seat belts are damaged, modified,
ex treme lydirty, bleached or dyed R
Ifth e seat belt buckle is damaged or
ex treme lydirty
R Ifth e seat belt tensioners, seat belt
anchorages or seat belt retractors ha ve
been modified
Seat belts may be damaged in an accident,
although the damage may not be visible, e.g.
due tosplinters of glass.
Modified or damaged seat belts may tear or
fa il, e.g. in an accident.
Modified seat belt tensioners could acciden‐
ta lly trigger or failto function as intended. #
Never modify the seat belts, seat belt
te nsioners, seat belt anchorages or seat
belt retractors. #
Makesure that the seat belts are
undamaged, not wornand clean. #
Alw ays ha vethe seat belts checked
immediately af ter an accident at a
qu alified specialist workshop. Mercedes-Benz
recommends that you use seat
belts which ha vebeen appr ovedfo ryo ur vehicle
by Mercedes-Benz.
The sport seat is designed forth est andard
th re e-point seat belt. If youfit a di fferent multi‐
point seat belt, e.g. sport or racing seat belts,
th ere stra int sy stem cann otprov ide the intended
le ve l of pr otection.
Depending on the type of seat, there may be
openings in the seat backrest. These openings
ha ve no function. &
WARNING Risk of inju ryor fata l injury
due tomodified seat belt sy stems
If yo ufe ed seat belts thro ugh the opening in
th e seat backrest, the seat backrest may be
damaged or may even break in theeve nt of
an accident. #
Only use thest andard thre e-point seat
belt. #
Never modify the seat belt sy stem. 34
Occupant saf ety

&
WARNING Risk of inju ryor death from
deplo yedpy rotech nic seat belt tension‐
ers
Py rotech 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 qualified specialist work‐
shop. Mercedes-Benz
recommends that you ha vethe
ve hicle towe dto aqu alified specialist workshop
af te r an accident.
* NO
TEDama gecaused 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. #
Alw ays ensure that an unused seat belt
is fully retracted. Fa
stening seat belts If
th e seat belt is pulled quickly or sharpl y,the
seat belt retractor lo cks. The seat belt stra p can‐
not be pulled out any fur ther. #
Alw ays engage seat belt tongue 2ofthe
seat belt into seat belt buckle 1ofthe cor‐
re sponding seat. Ve
hicles with automatic front passen ger
front airbag shu toff:
* NO
TEDeployment of the seat belt ten‐
sioner and side impact airbag when the
front passenger seat is unoccupied If
th e seat belt tongue is engaged in the seat
belt buckle of the unoccupied front
passenger seat, the seat belt tensioner and
th e side impact airbag may also deploy in the
ev ent of an accident along with other sys‐
te ms. #
Only one person should use each seat
belt at any one time. Ve
hicles without automatic front passen ger
front airbag shu toff:
* NO
TEDeployment of the seat belt ten‐
sioner when the front passenger seat is
unoccupied If
th e seat belt tongue is engaged in the seat
belt buckle of the unoccupied front
passenger seat, the seat belt tensioner may Occupant sa
fety 35

also deploy in
theev ent of an accident along
with other sy stems. #
Only one person should use each seat
belt at any one time. Seat belt adjustment function
Ve
hicles with PRE-SAFE ®
:if th e front seat belt
is not pulled tight across your body, the seat belt
adjustment may automatically apply a cer tain
tigh tening 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 sys‐
te m (→ page 36). Re
leasing a seat belt #
Press there lease button in the seat belt
buckle and guide the seat belt back with the
seat belt tongue. Ac
tivating/deactivating seat belt adjustment
via the multimedia sy stem Multimedia sy
stem:
, © .
Settings .
Vehicle #
Activate or deacti vate Belt adjustment. Seat belt
warning function for the driver and
front passen ger The
ü seat belt warning lamp in the instru‐
ment display is a reminder that all vehicle occu‐
pants must weartheir seat belts cor rectly.
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. Fu
nction of there ar seat belt status display The
rear seat belt status display is on lyavailable
fo r cer tain countries. The
rear seat belt status display informs you
which rear seat belt is not fastened.
Yo u can immediately dismiss there ar seat belt
st atus display using the back button on the left-
hand side of thesteering wheel (→ page 250).
If a vehicle occupant unfas tens a seat belt in the
re ar while theve hicle is motion, there ar seat
belt status display appears again.
In addition, an acoustic warning tone may sound.
In this case, there ar seat belt status display
cannot be hidden using the back button on the
left-hand side of thesteering wheel. 36
Occupant saf ety

Airbags
Overview of airbags
1
Knee airbag
2 Driver's airbag
3 Front passenger front airbag
4 Window airbag
5 Side impact airbag
The ins tallation location of an airbag is identified
by the AIRB AGsymbol.
When enabled, an airbag can pr ovide additional
pr otection forth ere spective vehicle occupant. Pot
ential pr otection from each airbag: AIRB
AG Potential pr otection for
…
Knee airbag Thigh, knee and lo wer leg
Driver's airbag,
front passenger
front airbag Head and
ribcage
Wi ndow airba gHead
Side impact air‐
bag Ribcage and pelvis *
NO
TEImpo rtant points toremember if
th e front passenger seat is unoccupied In an accident,
the components of the
re stra int sy stem may deploy unnecessarily
on the 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
the front passenger seat is
unoccupied. #
Stow objects in a suitable place. #
Only one person should use each seat
belt at any one time. &
WARNING Risk of inju ryor fata l injuries
if th e front passenger airbag is enabled
If th e front passenger front airbag is enabled,
a ch ild on the front passenger seat may be
st ru ck bythe front passenger airbag during
an accident.
NEVER use a rear wa rd-facing child restra int
sy stem on a seat with an ENABLED FRONT
AIRB AG, DEAT H or SERIOUS INJU RYtothe
CH ILD can occur. When
fitting a child restra int sy stem tothe front
passenger seat, obser vetheve hicle-specific
information (→ page 52). Also, alw ays obser ve
th e no tes on rear wa rd-facing or forw ard-facing
ch ild restra int sy stems on the front passenger
seat. Occupant saf
ety37