2013 MERCEDES-BENZ CLA belt

Airbag deployment only provides increased
protection if the seat belt is worn correctly.
The seat belt helps, firstly, to keep the vehicle
occupant in the best position in relation to the
airbag. Secondly, in a head-on collision, for
example, the seat belt restricts movement of
the vehicle occupant towards the point of
impact.
SRS (Supplemental Restraint System)
Introduction
Supplemental Restraint System (SRS) with:
R the 6 SRS warning lamp
R airbags
R airbag control unit (with crash sensors)
R belt tensioners for the front seat belts and
the outer seat belts in the rear
R seat belt force limiters for the front seat
belts and the outer seat belts in the rear
SRS reduces the risk of vehicle occupants
coming into contact with parts of the vehi-
cle's interior in the event of an accident. It can
also reduce the forces to which vehicle occu-
pants are subjected during an accident.
SRS warning lamp
GWARNING
If SRS is malfunctioning, child restraint sys-
tem components may be triggered uninten-
tionally or might not be triggered at all in the
event of an accident with a high rate of vehicle
deceleration. There is an increased risk of
injury, possibly even fatal.
Have SRS checked and repaired immediately
at a qualified specialist workshop.
SRS functions are checked regularly when
you switch on the ignition and when the
engine is running. Therefore, malfunctions
can be detected in good time.
The 6 SRS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out no later than a few seconds
after the engine is started.
The SRS components are in operational read-
iness when the 6 SRS warning lamp goes
out while the engine is running.
A malfunction has occurred if:
R the 6 SRS warning lamp does not light
up when the ignition is switched on
R the engine is running and the 6 SRS
warning lamp does not go out after a few
seconds
R the engine is running and the 6 SRS
warning lamp lights up again
Triggering of belt tensioners and air-
bags
During the first stage of a collision, the airbag
control unit evaluates important physical
data relating to vehicle deceleration or accel-
eration, such as:
R duration
R direction
R magnitude
Based on the evaluation of this data, the air-
bag control unit pre-emptively triggers the
belt tensioners in the first stage.
If there is an even higher rate of vehicle decel-
eration or acceleration in a longitudinal direc-
tion, the front airbags are also deployed.
Your vehicle has adaptive, two-stage front air-
bags. The airbag control unit evaluates vehi-
cle deceleration or acceleration in the event
of a collision. In the first deployment stage,
the front airbag is filled with enough propel-
lant gas to reduce the risk of injuries. The
front airbag is fully deployed if a second
deployment threshold is reached within a few
milliseconds.
The belt tensioner and airbag triggering
thresholds are variable and are adapted to the
detected rate of deceleration or acceleration
of the vehicle. This process is pre-emptive in
nature. The triggering process must take
place in good time at the start of the collision.
Occupant safety41SafetyZ

The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R the distribution of forces during the colli-
sion
R the collision angle
R the deformation characteristics of the vehi-
cle
R the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an airbag,
nor do they provide an indication of airbag
deployment.
The vehicle may be deformed significantly,
e.g. the bonnet or the wing, without an airbag
being deployed. This is the case if only parts
which are relatively easily deformed are affec-
ted and the rate of deceleration is not high.
Conversely, airbags may be deployed even
though the vehicle suffers only minor defor-
mation. This is the case if, for example, very
rigid vehicle parts such as longitudinal body
members are hit, and sufficient deceleration
occurs as a result.
i The front belt tensioners can only be trig-
gered if the seat belt tongues on the front
seats are correctly engaged in the seat belt
buckles.
i Not all airbags are deployed in an acci-
dent. The different airbag systems work
independently of each other.
How the airbag system works is deter-
mined by predicting the severity of the acci-
dent, especially vehicle deceleration or
acceleration, and the type of accident:
R head-on collision
R side impact
R overturnAirbags
Important safety notesGWARNING
Airbags provide additional protection; they
are not, however, a substitute for seat belts.
Observe the following notes to reduce the risk
of serious or even fatal injury caused by airbag
deployment:
R all vehicle occupants – in particular, preg-
nant women – must wear their seat belt
correctly at all times and lean back against
the backrest, which should be positioned
as close to the vertical as possible. The
head restraint must support the back of the
head at about eye level.
R always secure children less than
1.50 m tall or under 12 years of age in suit-
able child restraint systems.
R all vehicle occupants must select a seat
position that is as far away from the airbag
as possible. The driver's seat position must
allow the vehicle to be driven safely. The
driver's chest should be as far away from
the centre of the driver's airbag cover as
possible.
R move the front-passenger seat as far back
as possible. This is especially important if
you have secured a child in a child restraint
system on the front-passenger seat.
R vehicle occupants – in particular, children
– must not lean their head into the area of
the window in which the sidebag/window-
bag is deployed.
R rearward-facing child restraint systems
must not be fitted to the front-passenger
seat unless the front-passenger airbag has
been disabled. On the front-passenger
seat, the front-passenger airbag is disabled
if a child restraint system with a trans-
ponder for automatic child seat recognition
is fitted to the front-passenger seat in a
vehicle equipped with automatic child seat
recognition. The 4 PASSENGER AIRBAG
42Occupant safetySafety

Front airbags
! Do not place heavy objects on the front-
passenger seat. This could cause the sys-
tem to identify the seat as being occupied.
In the event of an accident, the restraint
systems on the front-passenger side may
be triggered and have to be replaced.
Driver's airbag : deploys in front of the
steering wheel; front-passenger front air-
bag ; deploys in front of and above the glove
compartment.
The front airbags increase protection for the
driver's and front-passenger's head and
chest.
They are deployed:
R at the start of an accident with a high rate
of vehicle acceleration or deceleration in a
longitudinal direction.
R if the system determines that airbag
deployment can offer additional protection
to that provided by the seat belt.
R depending on whether the seat belt is being
used.
R independently of other airbags in the vehi-
cle.
If the vehicle overturns, the front airbags are
generally not deployed.
Vehicles with automatic child seat recog-
nition in the front-passenger seat: front-
passenger airbag ; is only activated if the
system determines that the front-passenger
seat is occupied. The PASSENGER AIRBAG
OFF indicator lamp on the centre console
does not light up ( Y page 53).
If a child restraint system is fitted to the front-
passenger seat and the PASSENGER AIRBAG
OFF indicator lamp on the centre console is
not on:
R a child restraint system without a trans-
ponder for automatic child seat recognition
has been fitted or
R a child restraint system with a transponder
has been fitted incorrectly
Driver's kneebag
Driver's kneebag : deploys underneath the
steering column. The driver's kneebag is trig-
gered together with the front airbag. The driv-
er's kneebag is designed to operate together
with the front airbags in frontal impacts if cer-
tain thresholds are exceeded. The driver's
kneebag operates best in conjunction with
correctly positioned and fastened seat belts.
Driver's kneebag : increases the driver's
protection against:
R knee injuries
R thigh injuries
R lower leg injuries
Sidebags
GWARNING
Unsuitable seat covers may obstruct or even
prevent deployment of the airbags integrated
into the seats. The airbags may then fail to
protect the vehicle occupants as intended.
Operation of the automatic child seat recog-
44Occupant safetySafety

nition may also be impaired. There is an
increased risk of injury, possibly even fatal.
Use only seat covers which have been specif-
ically approved for the respective seat by
Mercedes-Benz.GWARNING
Sensors to control the airbags are located in
the doors. Modifications or work not per-
formed correctly to the doors or door panel-
ling, as well as damaged doors, can lead to
the function of the sensors being impaired.
The airbags might therefore not function
properly any more. Consequently, the airbags
cannot protect vehicle occupants as they are
designed to do. This poses an increased risk
of injury.
Never modify the doors or parts of the doors.
Always have work on the doors or door pan-
elling carried out at a qualified specialist
workshop.
You should only use seat cover that have been
approved for your vehicle by Mercedes-Benz.
The seat covers must have a special tear
seam for sidebags. Otherwise, the sidebags
cannot deploy correctly and therefore cannot
provide the intended protection in the event
of an accident.
Front sidebags : and rear sidebags ;
deploy next to the outer seat cushions.
When deployed, the sidebags offer additional
protection of the thorax for occupants on the
front seats as well as also of the pelvis for the
vehicle occupants on the side of the vehicle
on which the impact occurs. However, they
do not protect the:
R head
R neck
R arms
The sidebags are deployed:
R on the side on which an impact occurs
R at the start of an accident with a high rate
of lateral vehicle deceleration or accelera-
tion, e.g. in a side impact
R independently of the use of the seat belt
R independently of the front airbags
R independently of the belt tensioners
If the vehicle overturns, the sidebags are gen-
erally not deployed. Sidebags are deployed if
the system detects high vehicle deceleration
or acceleration in a lateral direction and
determines that sidebag deployment can
offer additional protection to that provided by
the seat belt.
Windowbags
Windowbags : enhance the level of protec-
tion for the head (but not chest or arms), of
the vehicle occupants on the side of the vehi-
cle on which the impact occurs.
Windowbags : are integrated into the side
of the roof frame and deployed in the area
from the A-pillar to the C-pillar.
Occupant safety45SafetyZ

Windowbags are deployed:
R at the start of an accident with a high rate
of lateral vehicle deceleration or accelera-
tion, e.g. in a side impact
R on the side on which an impact occurs
R on the driver's and the front passenger's
side if the vehicle overturns and the system
determines that deployment can offer addi-
tional protection to that provided by the
seat belt
R independently of the use of the seat belt
R regardless of whether the front-passenger
seat is occupied
R independently of the front airbags
PRE-SAFE ®
(anticipatory occupant
protection)
! Make sure that there are no objects in the
footwell or behind the seats when moving
the seat back. There is a risk that the seats
and/or the objects could be damaged.
PRE-SAFE ®
takes pre-emptive measures to
protect occupants in certain hazardous sit-
uations. Although your vehicle is equipped
with a PRE-SAFE ®
system, the possibility of
injury in the event of an accident cannot be
ruled out.
Always adapt your driving style to suit the
prevailing road and weather conditions and
maintain a safe distance from the vehicle in
front. Drive carefully.
PRE-SAFE ®
intervenes:
R when BAS activates, e.g. in emergency
braking situations.
R when adaptive Brake Assist intervenes
powerfully on vehicles with DISTRONIC
PLUS.
R in critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely.
PRE-SAFE ®
takes the following measures
depending on the hazardous situation detec-
ted:
R the front seat belts are pre-tensioned.
R vehicles with the memory function: the
front-passenger seat is adjusted if it is in an
unfavourable position.
R if the vehicle skids, the panorama sliding
sunroof and the side windows are closed so
that only a small gap remains.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pretensioning. All settings made by
PRE-SAFE ®
can then be reversed.
If the seat belts are not released:XMove the backrest or seat back slightly, but
only when the vehicle is stationary.
Seat belt pretensioning is reduced and the
locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. More
information about seat-belt adjustment can
be found under "Seat-belt adjustment"
( Y page 48).
Seat belts
Important safety notes
GWARNING
A seat belt which is not worn correctly, or
which has not been engaged in the seat belt
buckle correctly, cannot provide the intended
level of protection. Under certain circumstan-
ces, this could cause severe or even fatal inju-
ries in the event of an accident.
Therefore, make sure that all occupants — in
particular, pregnant women — wear their seat
belts correctly at all times.
R The seat belt must fit snugly on your body
and must not be twisted.Therefore, avoid
wearing bulky clothing, e.g. a winter coat.
The shoulder section of the belt must be
routed across the centre of your shoulder
46Occupant safetySafety

— on no account across your neck or under
your arm — and pulled tight against your
upper body. The lap belt must always pass
across your lap as low down as possible, i.e.
over your hip joints — not across your abdo-
men. If necessary, push the seat belt
slightly downwards and adjust it by pulling
it in the direction the seat belt retracts.
R Do not route the seat belt strap over sharp
or fragile objects. Please make sure that
such objects are not on or in your clothing,
e.g. spectacles, pens or keys etc. The seat
belt strap could become damaged and tear
during an accident and you or other vehicle
occupants could be injured.
R Only one person should use each seat belt
at any one time. Children must never travel
sitting on the lap of another occupant. The
child will not be secured in the event of an
accident, heavy braking or sudden change
of direction. This may result in the child or
other occupants being seriously or fatally
injured.
R Persons under 1.50 m tall cannot wear the
seat belts correctly. For this reason secure
persons less than 1.50 m tall in specially
designed, suitable restraint systems.
R Children under 1.50 m tall and younger
than twelve years of age cannot wear the
seat belts correctly. For this reason secure
them in special suitable child restraint sys-
tems installed on a suitable seat. Additional
information can be found in the Operating
Instructions in the chapter "Safety", "Chil-
dren in the Vehicle". Observe the installa-
tion instructions of the child restraint sys-
tem manufacturer.
R Do not secure an object with a seat belt if
the seat belt is also being used by one of
the vehicle's occupants.GWARNING
The seat belt does not offer the intended level
of protection if the backrest is not in the
upright position. When braking or in the event
of an accident, you could slide underneath the
seat belt and sustain abdomen or neck inju-
ries, for example. This poses an increased risk
of injury or even fatal injury.
Adjust the seat properly before beginning
your journey. Always make sure that the seat
is in the upright position.GWARNING
Seat belts cannot perform their intended pro-
tective function if:
R they are damaged, modified, bleached or
coloured, or are very dirty
R the seat belt buckle is damaged or very
dirty
R modifications have been made to the seat
belt tensioners or belt anchorages
In the event of an accident, seat belts can
sustain damage that is not visible to the naked
eye, e. g. due to glass splinters. Modified or
damaged seat belts could tear or fail in the
event of an accident, for example. Modified
belt tensioners could deploy unexpectedly or
fail. There is an increased risk of serious or
even fatal injuries.
Never make modifications to seat belts, belt
tensioners, belt anchorages or seat belt
retractors. Make sure that the seat belts are
undamaged, are not worn and are clean.
Mercedes-Benz recommends that you only
use seat belts which have been approved
specifically for your vehicle by Mercedes-
Benz.
Seat belts are the most effective means of
restraining the movement of vehicle occu-
pants in the event of an accident. This
reduces the risk of vehicle occupants coming
into contact with parts of the vehicle interior.
Occupant safety47SafetyZ

Fastening seat beltsXAdjust the seat and move the backrest to
an almost vertical position ( Y page 94).XPull the seat belt smoothly through belt
sash guide :.XWithout twisting it, guide the shoulder sec-
tion of the seat belt across the middle of
your shoulder and the lap section across
your pelvis.XEngage belt tongue ; in buckle =.
Seat belt adjustment: if necessary, the driv-
er's and front-passenger seat belts auto-
matically adjust to the upper body
( Y page 48).XIf necessary, adjust the seat belt to the
appropriate height ( Y page 48).XIf necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
Information on releasing the seat belt with
release button ?(Y page 49).
Seat belt adjustment
The seat-belt adjustment function adjusts the
driver's and front-passenger seat belt to the
upper body of the occupants.
The belt strap is tightened slightly when:
R you engage the belt tongue in the belt
buckle and you then turn the key to position
2 in the ignition lock.
R the key is in position 2 in the ignition lock
and you then engage the belt tongue in the
buckle.
The seat-belt adjustment will apply a certain
tightening force if any slack is detected
between the occupant and the seat belt. Do
not hold on to the seat belt tightly while it is
adjusting. You can switch the seat-belt
adjustment on and off in the on-board com-
puter ( Y page 225).
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. More
information about PRE-SAFE ®
can be found
in the "PRE-SAFE ®
(preventative occupant
protection)" section ( Y page 46).
Belt height adjustment
You can adjust the belt height for the front
seats. Adjust the belt to a height that allows
the upper part of the seat belt to be routed
across the centre of your shoulder.
XTo raise: slide the belt sash guide upwards.
The belt sash guide engages in various posi-
tions.XTo lower: press and hold belt sash guide
release :.XSlide the belt sash guide downwards.XLet go of belt sash guide release : and
make sure that the belt sash guide has
engaged.48Occupant safetySafety

Releasing the seat belts
! Make sure that the seat belt is fully rolled
up. Otherwise, the seat belt or belt tongue
will be trapped in the door or in the seat
mechanism. This could damage the door,
the door trim panel and the seat belt. Dam-
aged seat belts can no longer fulfil their
protective function and must be replaced.
Visit a qualified specialist workshop.
XPress release button ? on belt buckle =.XGuide belt tongue ; back to belt sash
guide :.
Belt warning for the driver and front
passenger
The 7 seat belt warning lamp in the instru-
ment cluster is a reminder for all occupants
to fasten their seat belts. It may light up con-
tinuously or flash. In addition, a warning tone
may sound.
The 7 seat belt warning lamp goes out and
the warning tone ceases when the driver and
the front passenger have fastened their seat
belt.
Only for certain countries: the 7 seat belt
warning lamp lights up for six seconds after
every engine start. It lights up regardless of
whether the driver's and front-passenger seat
belts have already been fastened. If the driv-
er's and front-passenger seat belts have
already been fastened, the 7 seat belt
warning lamp then goes out.
i For more information on the 7 seat
belt warning lamp, see "Warning and indi-
cator lamps in the instrument cluster, seat
belt" ( Y page 255).
Rear seat belt status indicator
Example: rear seat belt status indicator
The rear-compartment seat belt status indi-
cator indicates the rear seat on which the belt
is fastened. In the example, the occupant on
the right rear seat, when viewed in the direc-
tion of travel, is secured. The ü symbol in
the display indicates a fastened seat belt. If a
seat belt is not fastened or if a seat is not
occupied, the ý symbol is displayed.
The rear-compartment seat belt status indi-
cator appears in the multifunction display for
around 30 seconds if:
R you drive off and reach a speed of approx-
imately 10 km/h.
R the rear passengers fasten or unfasten
their seat belts while the vehicle is in
motion.
R someone gets in or out of the vehicle and
the vehicle drives off again.
You can also cancel the rear seat belt status
indicator immediately ( Y page 226).
i The status indicator for the rear-compart-
ment seat belts is only available for certain
countries.
Occupant safety49SafetyZ