2017 MERCEDES-BENZ CLS warning

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

You should only use seat covers that have
been approved for the respective seat by
Mercedes-Benz.
Front side impact air bags C and rear side
impact air bags D deploy next to the outer bol-
ster of the seat backrest.
When deployed, the side impact air bag offers
additional thorax protection. However, it does
not protect the: R
head R
neck R
arms
In the event of a side impact, the side impact air
bag is deployed on the side on which the impact
occurs.
The side impact air bag on the front-passenger
side deploys under the following conditions: R
the OCS system detects that the front-
passenger seat is occupied or R
the belt tongue is engaged in the belt buckle
of the front-passenger seat
If the belt tongue is engaged in the belt buckle,
the side impact air bag on the front-passenger
side deploys if an appropriate accident situation
occurs. In this case, deployment is independent
of whether the front-passenger seat is occupied
or not.
Pelvis 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.
You should only use seat covers that have
been approved for the respective seat by
Mercedes-Benz.
Pelvis air bags C deploy below next to the outer
seat cushions.
When activated, the pelvis air bag enhances the
level of protection of the vehicle occupants on
the side of the vehicle on which the impact
occurs.
The pelvis air bag is deployed on the side of the
impact.
The pelvis air bag on the front-passenger side
does not deploy under the following conditions: R
the OCS detects that the front-passenger
seat is unoccupied or R
the belt tongue is not engaged in the belt
buckle of the front-passenger seat.
If the belt tongue is engaged in the belt buckle,
the pelvis air bag on the front-passenger side
deploys if an appropriate accident situation
occurs. In this case, deployment is independent
of whether the front-passenger seat is occupied
or not.48
Occupant safety
Safety

PASSENGER AIR BAG OFF indicator lamp C
shows you whether the front-passenger front air
bag is deactivated. X
Turn the SmartKey to position 1 or 2 in the
ignition lock or on vehicles with KEYLESS-GO,
press the Start/Stop button once or twice.
The system carries out self-diagnostics.
The PASSENGER AIR BAG OFF indicator lamp
must light up for approximately six seconds.
The PASSENGER AIR BAG OFF indicator lamp
then displays the status of the front-passenger
front air bag. If the status of the front-passenger
front air bag changes while the vehicle is in
motion, an air bag display message may appear
in the instrument cluster ( Y
page 210). When
the front-passenger seat is occupied, always
pay attention to the PASSENGER AIR BAG OFF
indicator lamp. Be aware of the status of the
front-passenger front air bag both before and
during the journey.
If the PASSENGER AIR BAG OFF indicator
lamp: R
is lit : the front-passenger front air bag is
deactivated. It will then not be deployed in the
event of an accident. R
is not lit : the front-passenger front air bag is
enabled. If, in the event of an accident, all
deployment criteria are met, the front-
passenger front air bag is deployed.
G WARNING
If the PASSENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is
disabled. It will not be deployed in the event of
an accident and cannot perform its intended
protective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
When the front-passenger seat is occupied,
always ensure that: R
the classification of the person in the front-
passenger seat is correct and the front-
passenger front air bag is enabled or disa- bled in accordance with the person in the
front-passenger seat R
the front-passenger seat has been moved
back as far back as possible. R
the person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag is correct.
G WARNING
If you secure a child in a child restraint system
on the front-passenger seat and the
PASSENGER AIR BAG OFF indicator lamp is
off, the front-passenger front air bag can
deploy in the event of an accident. The child
could be struck by the air bag. This poses an
increased risk of injury or even fatal injury.
Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
G WARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too
close to the dashboard, the child could, in the
event of an accident: R
come into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example R
be struck by the air bag if the PASSENGER
AIR BAG OFF indicator lamp is off
This poses an increased risk of injury or even
fatal injury.
Move the front-passenger seat as far back as
possible. Always make sure that the shoulder
belt strap is correctly routed from the vehicle
belt sash guide to the shoulder belt guide on
the child restraint system. The shoulder belt
strap must be routed forwards and down-
wards from the vehicle belt sash guide. If nec-
essary, adjust the vehicle belt sash guide and
the front-passenger seat accordingly. Always
observe the child restraint system manufac-
turer's installation instructions.50
Occupant safety
Safety

If OCS determines that: R
the front-passenger seat is unoccupied, the
PASSENGER AIR BAG OFF indicator lamp
lights up after the system self-test and
remains lit. This indicates that the front-
passenger front air bag is deactivated. R
the front-passenger seat is occupied by a
child of up to twelve months old, in a standard
child restraint system, the PASSENGER AIR
BAG OFF indicator lamp lights up after the
system self-test and remains lit. This indi-
cates that the front-passenger front air bag is
deactivated.
But even in the case of a twelve-month-old
child, in a standard child restraint system, the
PASSENGER AIR BAG OFF indicator lamp can
go out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated. The result of the classification is
dependent on, among other factors, the child
restraint system and the child's stature. It is
recommended that you install the child
restraint system on a suitable rear seat. R
the front-passenger seat is occupied by a per-
son of smaller stature (e.g. a teenager or
small adult), the PASSENGER AIR BAG OFF
indicator lamp lights up and remains lit after
the system self-test depending on the result
of the classification or, alternatively, goes out. -
If the PASSENGER AIR BAG OFF indicator
lamp is off, move the front-passenger seat
as far back as possible. Alternatively, a per-
son of smaller stature can sit on a rear seat. -
If the PASSENGER AIR BAG OFF indicator
lamp is lit, a person of smaller stature
should not use the front-passenger seat. R
the front-passenger seat is occupied by an
adult or a person of adult stature, the
PASSENGER AIR BAG OFF indicator lamp
goes out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated.
If children are traveling in the vehicle, be sure to
observe the notes on "Children in the vehicle"
( Y
page 58).
When the occupant classification system (OCS)
is malfunctioning, the red u restraint system
warning lamp in the instrument cluster and the
PASSENGER AIR BAG OFF indicator lamp light
up simultaneously. The front-passenger front air
bag is deactivated in this case and does not
deploy during an accident. Have the Occupant
C lassification System (OCS) checked and repaired immediately at a qualified specialist
workshop. Mercedes-Benz recommends that
you use an authorized Mercedes-Benz Center
for this purpose.
If the front-passenger seat, the seat cover or the
seat cushion are damaged, have the necessary
repair work carried out at a qualified specialist
workshop. Mercedes-Benz recommends that
you use an authorized Mercedes-Benz Center
for this purpose.
For safety reasons, Mercedes-Benz recom-
mends that you only use seat accessories that
have been approved by Mercedes-Benz.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag will
also deploy. The Occupant Classification Sys-
tem (OCS) categorizes the occupant in the front-
passenger seat. Depending on that result, the
front-passenger front air bag is either enabled or
deactivated.
System self-test
G DANGER
If the PASSENGER AIR BAG OFF indicator
lamp does not light up during the system self-
test, then the system is malfunctioning. The
front-passenger front air bag might be trig-
gered unintentionally or might not be trig-
gered at all in the event of an accident with
high deceleration. This poses an increased
risk of injury or even fatal injury.
In this case the front-passenger seat may not
be used. Do not install a child restraint system
on the front-passenger seat. Have the Occu-
pant Classification System (OCS) checked
and repaired immediately at a qualified spe-
cialist workshop.
G WARNING
If the PASSENGER AIR BAG OFF indicator
lamp remains lit after the system self-test, the
front-passenger front air bag is disabled. It will
not be deployed in the event of an accident. In
this case, the front-passenger front air bag
cannot perform its intended protective func-
tion, e.g. when a person is seated in the front-
passenger seat.Occupant safety 51
Safety Z

That person could, for example, come into
contact with the vehicle's interior, especially
if the person is sitting too close to the dash-
board. This poses an increased risk of injury or
even fatal injury.
When the front-passenger seat is occupied,
always ensure that: R
the classification of the person in the front-
passenger seat is correct and the front-
passenger front air bag is enabled or disa-
bled in accordance with the person in the
front-passenger seat R
the person is seated properly with a cor-
rectly fastened seatbelt R
the front-passenger seat has been moved
as far back as possible
If the PASSENGER AIR BAG OFF indicator
lamp remains lit when it should not, the front-
passenger seat may not be used. Do not
install a child restraint system on the front-
passenger seat. Have the Occupant Classifi-
cation System (OCS) checked and repaired
immediately at a qualified specialist work-
shop. G WARNING
Objects between the seat surface and the
child restraint system could affect OCS oper-
ation. This could result in the front-passenger
air bag not functioning as intended during an
accident. This poses an increased risk of
injury or even fatal injury.
Do not place any objects between the seat
surface and the child restraint system. 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, as far as
possible, be resting on the backrest of the
front-passenger seat. Always comply with the
child restraint system manufacturer's instal-
lation instructions.
After the system self-test, the PASSENGER AIR
BAG OFF indicator lamp displays the status of
the front-passenger front air bag ( Y
page 49).
For more information about the OCS, see "Prob-
lems with the Occupant Classification System"
( Y
page 52).
Problems with the Occupant Classification System (OCS) Be sure to observe the notes on "System self-test" ( Y
page 51).52
Occupant safety
Safety

Problem
Possible causes/consequences and P Solutions
The PASSENGER AIR
BAG OFF indicator lamp
lights up and remains lit,
even though the front-
passenger seat is occu-
pied by an adult or a per-
son of a stature corre-
sponding to that of an
adult. The classification of the person on the front-passenger seat is incor-
rect. X
Make sure the conditions for a correct classification of the person
on the front-passenger seat are met ( Y
page 49).X
If the PASSENGER AIR BAG OFF indicator lamp remains lit, the front-
passenger seat may not be used. X
Have OCS checked as soon as possible at an authorized Mercedes-
Benz Center.
The PASSENGER AIR
BAG OFF indicator lamp
does not light up and/or
does not stay on.
The front-passenger seat
is: R
unoccupied R
occupied with the
weight of a child up to
twelve months old in a
child restraint system OCS is malfunctioning. X
Make sure there is nothing between the seat cushion and the child
seat. X
Make sure that the entire base of the child restraint system rests 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. If necessary,
adjust the position of the front-passenger seat. X
When installing the child restraint system, make sure that the seat
belt is tight. Do not pull the seat belt tight using the front-passenger
seat adjustment. This could result in the seat belt and the child
restraint system being pulled too tightly. X
Check for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to the child
restraint system. If necessary, adjust the head restraint accord-
ingly. X
Make sure that no objects are applying additional weight onto the
seat. X
If the PASSENGER AIR BAG OFF indicator lamp remains off, do not
install a child restraint system on the front-passenger seat. It is
recommended that you install the child restraint system on a suit-
able rear seat. X
Have OCS checked as soon as possible at an authorized Mercedes-
Benz Center.
Deployment of Emergency Tensioning
Devices and air bags
Important safety notes
G WARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible. G WARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified special-
ist workshop in order to have a deployed air
bag replaced.
It is important for your safety and that of your
passenger to have deployed air bags replaced
and to have any malfunctioning air bags
repaired. This will help to make sure the air bagsOccupant safety 53
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