2017 MERCEDES-BENZ CLS window

driver or front passenger have fastened their
seat belts.
If the driver or front passenger unfasten their
seat belts during the journey, the seat belt warn-
ing is activated again.
Air bags
Introduction The installation point of an air bag can be rec-
ognized by the AIR BAG symbol.
An air bag complements the correctly fastened
seat belt. It is no substitute for the seat belt. The
air bag provides additional protection in appli-
cable accident situations.
Not all air bags are deployed in an accident. The
different air bag systems function independ-
ently from one another ( Y
page 53).
However, no system available today can com-
pletely eliminate injuries and fatalities.
It is also not possible to rule out a risk of injury
caused by an air bag due to the high speed at
which the air bag must be deployed.
Important safety notes
G WARNING
If you do not sit in the correct seat position,
the air bag cannot protect as intended and
could even cause additional injury when
deployed. This poses an increased risk of
injury or even fatal injury.
To avoid hazardous situations, always make
sure that all of the vehicle's occupants: R
have fastened their seat belts correctly,
including pregnant women R
are sitting correctly and maintain the great-
est possible distance to the air bags R
follow the following instructions
Always make sure that there are no objects
between the air bag and the vehicle's occu-
pants. R
Adjust the seats properly before beginning
your journey. Always make sure that the seat
is in an almost upright position. The center of the head restraint must support the head at
about eye level. R
Move the driver's and front-passenger seats
as far back as possible. The driver's seat posi-
tion must allow the vehicle to be driven safely. R
Only hold the steering wheel on the outside.
This allows the air bag to be fully deployed. R
Always lean against the backrest while driv-
ing. Do not lean forwards or lean against the
door or side window. You may otherwise be in
the deployment area of the air bags. R
Always keep your feet in the footwell in front
of the seat. Do not put your feet on the dash-
board, for example. Your feet may otherwise
be in the deployment area of the air bag. R
For this reason, always secure persons less
than 5 ft (1.50 m) tall in suitable restraint sys-
tems. Up to this height, the seat belt cannot
be worn correctly.
If a child is traveling in your vehicle, also
observe the following notes: R
Always secure children under twelve years of
age and less than 5 ft (1.50 m) tall in suitable
child restraint systems. R
Child restraint systems should be installed on
the rear seats. R
Only secure a child in a rearward-facing child
re straint system on the front-passenger seat
when the front-passenger front air bag is
deactivated. If the PASSENGER AIR BAG OFF
indicator lamp is permanently lit, the front-
passenger front air bag is deactivated
( Y
page 42). R
Always observe the instructions and safety
notes on the "Occupant Classification System
(OCS)" ( Y
page 49) and on "Children in the
vehicle" ( Y
page 58 )i n addition to the child
restraint system manufacturer's installation
and operating instructions.
Objects in the vehicle interior may prevent
an air bag from functioning correctly. Before
starting your journey and to avoid risks resulting
from the speed of the air bag as it deploys, make
sure that: R
there are no people, animals or objects
between the vehicle occupants and an air
bag. R
there are no objects between the seat, door
and B-pillar. R
no hard objects, e.g. coat hangers, hang on
the grab handles or coat hooks.46
Occupant safety
Safety

R
no accessories, such as cup holders, are
attached to the vehicle within the deployment
area of an air bag, e.g. to doors, side windows,
rear side trim or side walls. R
no heavy, sharp-edged or fragile objects are in
the pockets of your clothing. Store such
objects in a suitable place.
G WARNING
If you modify the air bag cover or affix objects
such as stickers to it, the air bag can no longer
function correctly. There is an increased risk
of injury.
Never modify an air bag cover or affix objects
to it.
G WARNING
Sensors to control the air bags are located in
the doors. Modifications or work not per-
formed correctly to the doors or door panel-
ing, as well as damaged doors, can lead to the
function of the sensors being impaired. The air
bags might therefore not function properly
anymore. Consequently, the air bags cannot
protect vehicle occupants as they are
designed to do. There is an increased risk of
injury.
Never modify the doors or parts of the doors.
Always have work on the doors or door pan-
eling carried out at a qualified specialist work-
shop.
Front air bags
Driver's air bag C deploys in front of the steer-
ing wheel. Front-passenger front air bag D
deploys in front of and above the glove box. When deployed, the front air bags offer addi-
tional head and thorax protection for the occu-
pants in the front seats.
The PASSENGER AIR BAG OFF indicator lamp
informs you about the status of the front-
passenger front air bag ( Y
page 42).
The front-passenger front air bag will only
deploy if: R
the system, based on the OCS weight sensor
readings, detects that the front-passenger
seat is occupied ( Y
page 49)R
the PASSENGER AIR BAG OFF indicator lamp
does not light up ( Y
page 49)R
the restraint system control unit predicts a
high accident severity
Knee bags
Driver's knee bag C deploys under the steering
column and front-passenger knee bag D under
the glove box. The driver's and front-passenger
knee bags are triggered together with the front
air bags.
The driver's and front-passenger knee bags
offer additional thigh, knee and lower leg pro-
tection for the occupants in the front seats.
Side impact air bags
G WARNING
Unsuitable seat covers can obstruct or pre-
vent deployment of the air bags integrated
into the seats. Consequently, the air bags
cannot protect vehicle occupants as they are
designed to do. In addition, the operation of
the occupant classification system (OCS)
could be adversely affected. This poses an
increased risk of injury or even fatal injury.Occupant safety 47
Safety Z

Window curtain air bags
Window curtain air bags C are integrated into
the side of the roof frame and deployed in the
area from the A-pillar to the C-pillar.
When deployed, the window curtain air bag
enhances the level of protection for the head.
However, it does not protect the chest or arms.
In the event of a side impact, the window curtain
air bag is deployed on the side on which the
impact occurs.
If the system determines that they can offer
additional protection to that provided by the
seat belt, a window curtain air bag may be
deployed in other accident situations
( Y
page 53).
Occupant Classification System
(OCS)
Introduction The Occupant Classification System (OCS) cat-
egorizes the person in the front-passenger seat.
Depending on that result, the front-passenger
front air bag and front-passenger knee bag are
either enabled or deactivated.
The system does not deactivate: R
the side impact air bag R
the pelvis air bag R
the window curtain air bag R
the Emergency Tensioning Devices Requirements To be classified correctly, the front passenger
must sit: R
with the seat belt fastened correctly R
in an almost upright position with their back
against the seat backrest R
with their feet resting on the floor, if possible
If the front passenger does not observe these
conditions, OCS may produce a false classifica-
tion, e.g. because the front passenger: R
transfers their weight by supporting them-
selves on a vehicle armrest R
sits in such a way that their weight is raised
from the seat cushion
If it is absolutely necessary to install a child
restraint system on the front-passenger seat, be
sure to observe the correct positioning of the
child restraint system. Never place objects
under or behind the child restraint system, e.g. a
cushion. The entire base of the child restraint
system must always rest on the seat cushion of
the front-passenger seat. The backrest of the
forward-facing child restraint system must lie as
flat as possible against the backrest of the front-
passenger seat.
The child restraint system must not touch the
roof or be subjected to a load by the head
restraint. Adjust the angle of the seat backrest
and the head restraint position accordingly.
Only then can OCS be guaranteed to function
correctly. Always observe the child restraint sys-
tem manufacturer's installation and operating
instructions.
Occupant Classification System opera-
tion (OCS) Occupant safety 49
Safety Z

continue to perform their protective function for
the vehicle occupants in the event of a crash.
G WARNING
Emergency Tensioning Devices that have
deployed pyrotechnically are no longer opera-
tional and are unable to perform their inten-
ded protective function. This poses an
increased risk of injury or even fatal injury.
Have pyrotechnically triggered Emergency
Tensioning Devices replaced immediately at a
qualified specialist workshop.
An electric motor is used by PRE-SAFE ®
to trig-
ger the tightening of the seat belt in hazardous
situations. This procedure is reversible.
If Emergency Tensioning Devices are triggered
or air bags are deployed, you will hear a bang,
and a small amount of powder may also be
released. The u restraint system warning
lamp lights up.
Only in rare cases will the bang affect your hear-
ing. The powder that is released generally does
not constitute a health hazard, but it may cause
short-term breathing difficulties in people with
asthma or other respiratory problems. Provided
it is safe to do so, you should leave the vehicle
immediately or open the window in order to pre-
vent breathing difficulties.
Air bags and pyrotechnic Emergency Tensioning
Devices (ETDs) contain perchlorate material,
which may require special handling and regard
for the environment. National guidelines must
be observed during disposal. In California, see
www.dtsc.ca.gov/HazardousWaste/
Perchlorate/index.cfm .
Method of operation During the first stage of a collision, the restraint
system control unit evaluates important physi-
cal data relating to vehicle deceleration or accel-
eration, such as: R
duration R
direction R
intensity
Based on the evaluation of this data, the
restraint system control unit triggers the Emer-
gency Tensioning Devices during a frontal or
rear collision. An Emergency Tensioning Device can only be
triggered, if: R
the ignition is switched on R
the components of the restraint system are
operational. You can find further information
under: "Restraint system warning lamp"
( Y
page 42) R
the belt tongue is engaged in the buckle on
the respective front-passenger seat
The Emergency Tensioning Devices in the rear
compartment are triggered independently of the
lock status of the seat belts.
If the restraint system control unit detects a
more severe accident, further components of
the restraint system are activated independ-
ently of each other in certain frontal collision
situations: R
Front air bags and driver's knee bag R
Window curtain air bag, if the system deter-
mines that deployment can offer additional
protection to that provided by the seat belt
The front-passenger front air bag is activated or
deactivated depending on the person on the
front-passenger seat. The front-passenger front
air bag can only deploy in an accident if the
PASSENGER AIR BAG OFF indicator lamp is off.
Observe the information on the PASSENGER AIR
BAG OFF indica tor lamp ( Y
page 42).
Your vehicle has two-stage front air bags. During
the first deployment stage, the front air bag is
filled with propellant gas to reduce the risk of
injuries. The front air bag is fully deployed with
the maximum amount of propellant gas if a sec-
ond deployment threshold is reached within a
few milliseconds.
The activation threshold of the Emergency Ten-
sioning Devices and the air bag are determined
by evaluating the rate of vehicle deceleration or
acceleration which occurs at various points in
the vehicle. This process is pre-emptive in
nature. Deployment should take place in good
time at the start of the collision.
The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by: R
the distribution of forces during the collision R
the collision angle R
the deformation characteristics of the vehicle 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 deci-54
Occupant safety
Safety

sive role in the deployment of an air bag. Nor do
they provide an indication of air bag deploy-
ment.
The vehicle can be deformed considerably, with-
out an air bag being deployed. This is the case if
only parts which are relatively easily deformed
are affected and the rate of deceleration is not
high. Conversely, air bags may be deployed even
though the vehicle suffers only minor deforma-
tion. This is the case if, for example, very rigid
vehicle parts such as longitudinal body mem-
bers are hit, and sufficient deceleration occurs
as a result.
If the restraint system control unit detects a side
impact or if the vehicle rolls over, the applicable
components of the restraint system are activa-
ted independently of each other depending on
the apparent type of accident. R
Side impact air bags and pelvis air bag on the
side the impact takes place, independently of
the Emergency Tensioning Device and the use
of the seat belt on the driver's seat and outer
seats in the second row -
the OCS system detects that the front-
passenger seat is occupied or -
the belt tongue is engaged in the belt
buckle of the front-passenger seat R
Window curtain air bag on the side of impact,
independently of the use of the seat belt and
independently of whether the front-
passenger seat is occupied R
Emergency Tensioning Devices, if the system
determines that deployment can offer addi-
tional protection in this situation R
Window curtain air bags on the driver's and
front-passenger side in certain situations
when the vehicle rolls over, if the system
determines that deployment can offer addi-
tional protection to that provided by the seat
belt
i Not all air bags are deployed in an accident.
The different air bag systems work independ-
ently of each other.
How the air bag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or accel-
eration and the apparent type of accident: R
Frontal collision R
Side impact R
Rollover NECK-PRO head restraints/NECK-
PRO luxury head restraints
Important safety notes
G WARNING
The function of the head restraint may be
impaired if you: R
attach objects such as coat hangers to the
head restraints, for example R
use head restraint covers
If you do so, the head restraints cannot fulfill
their intended protective function in the event
of an accident. In addition, objects attached
to the head restraints could endanger other
vehicle occupants. There is an increased risk
of injury.
Do not attach any objects to the head
restraints and do not use head restraint cov-
ers.
Method of operation NECK-PRO head restraints/NECK-PRO luxury
head restraints offer additional protection
against head and neck injuries. In the event of a
rear collision of a certain severity, the NECK-
PRO head restraints/NECK-PRO luxury head
restraints on the driver's and front-passenger
seats are moved forwards and upwards. This
provides better head support.
If the NECK-PRO head restraints/NECK-PRO
luxury head restraints have been triggered in an
accident, reset the NECK-PRO head restraints/
NECK-PRO luxury head restraints on the driver's
seat and the front-passenger seat
( Y
page 56). Otherwise, the additional protec-
tion will not be available in the event of another
rear-end collision. You can see that a NECK-PRO
head restraint/NECK-PRO luxury head restraint
has been triggered if it is tilted forward and can
no longer be adjusted.
Mercedes-Benz recommends that you have the
functionality of the NECK-PRO head restraints/
NECK-PRO luxury head restraints checked at a
qualified specialist workshop after a rear-end
collision.Occupant safety 55
Safety Z

Function PRE-SAF E ®
intervenes:R
in emergenc y braking situations, e.g. when
BA S is activatedR
in critical driving situations, e.g. when physi-
cal limits are exceeded and th e vehicl e under-
steer s or oversteer s severelyR
on vehicles wit h th e Drivin g Assistanc e pack-
age: if BA S PLU S intervenes powerfully or th e
radar sensor system detect s an imminent
danger of collision in certai n situation s
PRE-SAF E ®
takes th e followin g measures
depending on th e hazardous situation detected:R
th e fron t seat belt s are pre-tensioned.R
th e front-passenger seat is adjusted if it is in
an unfavorable position .R
if th e vehicl e skids, th e side windows and th e
sliding sunroo f are closed.R
vehicles wit h a multicontour seat or active
multicontour seat : th e air pressur e in th e side
bolsters of th e backrest is increased.
If th e hazardous situation passes without result -
ing in an accident, PRE-SAF E ®
slackens th e belt
pre-tensioning . On vehicles wit h multicontour
seat s or active multicontour seats, th e air pres-
sure in th e side bolsters is reduce d again . All
setting s made by PRE-SAF E ®
can then be
reversed.
If th e seat belt pre-tensioning is no t reduced:X
Mov e th e seat backrest or seat bac k slightly
when th e ve hicl e i s stationary.
The seat belt pre-tensioning is reduce d and
th e lockin g mechanism is released.
The seat-belt adjustmen t is an integral part of
th e PRE-SAF E ®
convenience function . Informa-
tion about th e convenience function can be
foun d under "Belt adjustment" ( Y
page 45).
PRE-SAFE ®
PLUS (anticipatory occu-
pant protection system PLUS)
Introduction
PRE-SAF E ®
PLU S is only available in vehicles
wit h th e Drivin g Assistanc e package.
Usin g th e radar sensor system, PRE-SAF E ®
PLU S is able to detect that a head-on or rear-end
collision is imminent . In certai n hazardous sit - uations, PRE-SAF E ®
PLU S takes pre-emptive
measures to protect th e vehicl e occupants.
Important safety notes The intervention of PRE-SAF E ®
PLU S canno t
preven t an imminent collision .
The driver is no t warned about th e intervention
of PRE-SAF E ®
PLUS.
PRE-SAF E ®
PLU S does no t interven e if th e vehi-
cle is backin g up.
When driving , or when parking or exiting a park -
ing spac e wit h assistanc e from Active Parking
Assist , PRE-SAF E ®
PLU S will no t apply th e
brakes.
Function PRE-SAF E ®
PLU S intervenes in certai n situa-
tion s if th e radar sensor system detect s an
imminent head-on or rear-end collision .
PRE-SAF E ®
PLU S takes th e followin g measures
depending on th e hazardous situation detected: R
if th e radar sensor system detect s that a
head-on collision is imminent , th e seat belt s
are pre-tensioned. R
if th e radar sensor system detect s that a rear -
en d collision is imminent :-
th e brak e pressur e is increased if th e driver
applie s th e brakes when th e vehicl e is sta-
tionary. -
th e seat belt s are pre-tensioned.
The PRE-SAF E ®
PLU S braking application is can -
celed: R
if th e accelerato r pedal is depressed when a
gear is engage d R
if th e ris k of a collision passes or is no longer
detected R
if DISTRONI C PLU S indicates an intention to
pull away
If th e hazardous situation passes without result -
ing in an accident, th e original setting s are
restored .Occupant safety 57
Safety Z

Aut oma tic measures after an acci-
dent Immediately after an accident, th e followin g
measures are implemented, depending on th e
typ e and severity of th e impact :R
th e hazard warning lamp s are activatedR
th e emergenc y lighting is activatedR
th e vehicl e door s are unlocke dR
th e fron t side windows are loweredR
vehicles wit h a memory function : th e electri-
call y adjustable steering whee l is raisedR
th e engin e is switched off and th e fuel supply
is cut off R
vehicles wit h mbrace : automatic emergenc y
call
Children in the vehicle
Import ant safety notesAcciden t statistics sho w that children secured
in th e rear seat s are safer than children secured
in th e front-passenger seat . Fo r this reason ,
Mercedes-Benz strongly advises that you instal l
a child restrain t system on a rear seat . Children
are generally bette r protected there .
If a child younger than twelve years old and
under 5 ft (1.5 0 m) in height is traveling in the
vehicle: R
always secure the child in a child restraint
system suitable for Mercedes-Benz vehicles.
The child restraint system must be appropri-
ate to the age, weight and size of the child R
be sure to observe the instructions and safety
notes in this section in addition to the child
restraint system manufacturer's installation
instructions R
be sure to observe the instructions and safety
notes on the "Occupant classification system
(OCS)" ( Y
page 49)
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start the engine. In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
G WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
G WARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro-
tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Always ensure that all vehicle occupants have
their seat belts fastened correctly and are sitting
properly. Particular attention must be paid to
children.
Observe the safety notes on the seat belt
( Y
page 43) and the notes on correct use of seat
belts ( Y
page 44).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg) until they reach a height where a
three-point seat belt can be properly fastened
without a booster seat.
Special seat belt retractor
G WARNING
If the seat belt is released while driving, the
child restraint system will no longer be58
Children in the vehicle
Safety

You can thus avoid the risks that could arise as
a result of: R
an incorrectly categorized person in the front-
passenger seat R
the unintentional deactivation of the front-
passenger front air bag R
the unsuitable positioning of the child
restraint system, e.g. too close to the dash-
board
Rearward-facing child restraint system If it is absolutely necessary to install a rearward-
facing child restraint system on the front-
passenger seat, always make sure that the
front-passenger front air bag is deactivated.
Only if the PASSENGER AIR BAG OFF indicator
lamp is permanently lit ( Y
page 42) is the front-
passenger front air bag deactivated.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Forward-facing child restraint system If it is absolutely necessary to install a forward-
facing child restraint system on the front-
passenger seat, always move the front-
passenger seat as far back as possible. The
entire base of the child restraint system must
always rest on the seat cushion of the front-
passenger seat. The backrest of the child
restraint system must lie as flat as possible
against the backrest of the front-passenger
seat. The child restraint system must not touch
the roof or be subjected to a load by the head
restraint. Adjust the angle of the seat backrest
and the head restraint position accordingly.
Always make sure that the shoulder belt strap is
correctly routed from the vehicle belt outlet to
the shoulder belt guide on the child restraint
system. The shoulder belt strap must be routed
forwards and downwards from the vehicle belt
outlet. If necessary, adjust the vehicle belt out-
let and the front-passenger seat accordingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions. Child-proof locks
Important safety notes
G WARNING
If children are traveling in the vehicle, they
could: R
open doors, thus endangering other people
or road users R
exit the vehicle and be caught by oncoming
traffic R
operate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the
vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle.
Override feature for: R
the rear doors ( Y
page 63)R
the rear side windows ( Y
page 63)
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
G WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.62
Children in the vehicle
Safety