MERCEDES-BENZ CLS-Class 2013 W218 Service Manual

tamper with electronic components or their
software.
In this section, you will learn the most
important facts about the restraint system
components of the vehicle.
The restraint system consists of:
R seat belts
R child restraint systems
R LATCH-type (ISOFIX) child seat anchors
Additional protection is provided by:
R SRS (Supplemental Restraint System)
R NECK-PRO head restraints/NECK-PRO
luxury head restraints
R PRE-SAFE ®
R air bag system components with:
-PASSENGER
AIR BAG OFF indicator lamp
- front-passenger seat with Occupant
Classification System (OCS)
The different air bag systems work
independently of each other. The protective
functions of the system work in conjunction
with each other. Not all air bags are deployed
in an accident.
i See "Children in the vehicle" for
information on infants and children
traveling with you in the vehicle restraint
systems for infants and children
(Y page 58). SRS (Supplemental Restraint System)
Introduction SRS consists of:
R
6 SRS warning lamp
R Air bags
R Air bag control unit with crash sensors
R Emergency Tensioning Devices
R Belt force limiters
SRS reduces the risk of occupants coming
into contact with the vehicle's interior in the
event of an accident. It can also reduce the effect of the forces to which occupants are
subjected during an accident.
SRS warning lamp
G
WARNING
The SRS self-check has detected a
malfunction if the 6 SRS indicator lamp:
R does not light up at all
R does not go out after approximately four
seconds after the engine is started
R lights

up after the engine is started or while
the vehicle is in motion
For your safety, Mercedes-Benz strongly
recommends that you have the system
checked as soon as possible at a qualified
specialist workshop. SRS may otherwise fail
to activate when it is needed in the event of
an accident, which could lead to serious or
fatal injuries. SRS might also be activated
unexpectedly and unnecessarily, which could
also result in injury.
In addition, work carried out improperly on
SRS may render SRS inoperative or cause
unintended air bag deployment. Work on the
SRS system should only be carried out by
qualified specialist personnel. Consult a
qualified specialist workshop.
If it is necessary to modify an air bag system
to accommodate a person with disabilities,
contact an authorized Mercedes-Benz Center
for details. USA only: for further information,
contact our Customer Assistance Center at
1-800-FOR-MERCedes (1-800-367-6372).
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
readiness when the SRS 6 indicator lamp
goes out while the engine is running. Occupant safety
39
Safety Z

Safety guidelines for seat belts,
Emergency Tensioning Devices (ETDs)
and air bags
G
WARNING
R Damaged seat belts or seat belts that have
been subjected to stress in an accident
must be replaced. Their anchoring points
must also be checked. Only use seat belts
installed or supplied by an authorized
Mercedes-Benz Center.
R Air bags and pyrotechnic Emergency
Tensioning Devices (ETDs) contain
perchlorate material, which may require
special handling and regard for the
environment. Check your national disposal
guidelines. California residents, see
www.dtsc.ca.gov/HazardousWaste/
Perchlorate/index.cfm.
R Air bags and ETDs are designed to function
on a one-time-only basis. An air bag or ETD
that has deployed must be replaced. PRE-
SAFE ®
has electrically operated reversible
belt tensioners in addition to the
pyrotechnic ETDs.
R Do not pass seat belts over sharp edges.
They could tear.
R Do not make any modification that could
change the effectiveness of the seat belts.
R Do not bleach or dye seat belts as this may
severely weaken them. In a crash they may
not be able to provide adequate protection.
R No modifications of any kind may be made
to any components or wiring of the SRS.
R Do not change or remove any component
or part of the SRS.
R Do not install additional trim material, seat
covers, badges, etc. to the:
-padded steering wheel boss
- knee bag covers
- front-passenger air bag cover
- outer side of front seat bolsters
- side trim next to the rear seat backrest
- roof lining trim R
Do not install additional electrical/
electronic equipment on or near SRS
components and wiring.
R Keep

area between air bags and occupants
free of objects (e.g. packages, purses,
umbrellas, etc.).
R Do not hang items such as coat hangers
from the coat hooks or handles over the
door. These items may be thrown around in
the vehicle and cause head and other
injuries when the window curtain air bag is
deployed.
R Air bag system components will be hot after
an air bag has inflated. Do not touch them.
R Never place your feet on the instrument
panel, dashboard, or on the seat. Always
keep both feet on the floor in front of the
seat.
R Improper repair work on the SRS creates a
risk of rendering the SRS inoperative or
causing unintended air bag deployment.
Work on the SRS must therefore only be
performed by qualified technicians.
Contact an authorized Mercedes-Benz
Center.
R For your protection and the protection of
others, when scrapping the air bag unit or
ETD, our safety instructions must be
followed. These instructions are available
from any authorized Mercedes-Benz
Center.
R Given the considerable deployment speed,
required inflation volume, and the material
of the air bags, there is the possibility of
abrasions or other, potentially more serious
injuries resulting from air bag deployment.
If you sell your vehicle, Mercedes-Benz
strongly recommends that you inform the
subsequent owner that the vehicle is
equipped with SRS. Also, refer them to the
applicable section in the Operator's Manual. 40
Occupant safety
Safety

Air bags
Important safety notes G
WARNING
Air bags are designed to reduce the incidence
of injuries and fatalities in certain situations:
R frontal impacts (driver's and front-
passenger front air bags and knee bags)
R side
impacts (side impact air bags, window
curtain air bags and pelvis air bags)
R rollover (window curtain air bags)
However, no system available today can
completely eliminate injuries and fatalities.
When the air bags are deployed, a small
amount of powder is released. The powder
generally does not constitute a health hazard
and does not indicate that there is a fire in the
vehicle. In order to prevent potential
breathing difficulties, you should leave the
vehicle as soon as it is safe to do so. If you
have any breathing difficulty but cannot get
out of the vehicle after the air bag inflates,
then get fresh air by opening a window or
door. G
WARNING
In order to reduce the potential danger of
injuries caused during the deployment of the
front air bags, the driver and front passenger
must always be correctly seated and wear
their seat belts.
For maximum protection in the event of a
collision, you must always be in the normal
seat position with your back against the
backrest.

Fasten your seat belt and make sure
that it is correctly positioned on your body. As the air bag inflates with considerable
speed and force, a proper seating position
and correct positioning of the hands on the
steering

wheel will help to keep you at a safe
distance from the air bag. Occupants who are
not wearing their seat belt, are not seated
properly or are too close to the air bag can be
seriously injured or killed by an air bag, as it
inflates with great force instantaneously:
R sit with the seat belt fastened correctly and
in a position that is as upright as possible
with your back against the backrest.
R move the driver's seat as far back as
possible, still permitting proper operation
of vehicle controls. The distance from the
center of the driver's chest to the center of
the air bag cover on the steering wheel
must be at least 10 inches (25 cm). You
should be able to accomplish this by
adjusting the seat and steering wheel. If
you have any difficulties, please contact an
authorized Mercedes-Benz Center.
R do not lean your head or chest close to the
steering wheel or dashboard.
R only hold the steering wheel on the outside.
Placing hands and arms inside the rim can
increase the risk and potential severity of
hand/arm injury if the driver front air bag
inflates.
R adjust the front-passenger seat as far back
as possible from the dashboard when the
seat is occupied.
R occupants, especially children, should
never place their bodies or lean their heads
in the area of the door where the side
impact air bag inflates. This could result in
serious or fatal injuries should the side
impact air bag be deployed. Always sit as
upright as possible, wear the seat belt
properly and use an appropriately sized
infant restraint, toddler restraint or booster
seat recommended for the size and weight
of the child.
Failure to follow these instructions can result
in severe injuries to you or other occupants. Occupant safety
41
Safety
Z

If you sell your vehicle, it is important that you
make the buyer aware of this safety
information. Be sure to give the buyer this
Operator's Manual.
G
WARNING
Accident research shows that the safest place
for children in an automobile is in a rear seat.
A side impact air bag related injury may occur
if occupants, especially children, are not
properly seated or restrained when next to a
side impact air bag which needs to deploy
rapidly in a side impact in order to do its job.
To help avoid the possibility of injury, please
follow these guidelines:
(1) Always sit as upright as possible and use the seat belts properly.
Make sure that children 12 years
old

and under use an appropriately
sized child restraint, infant
restraint, or booster seat
recommended for the size and
weight of the child.
(2) Always wear seat belts properly.
If the air bags are deployed, you will hear a
bang,
and a small amount of powder may also
be released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard. The 6 SRS warning lamp
lights up.
The air bags are deployed if the air bag control
unit detects the need for deployment. Only in
the event of such a situation will the air bags
provide their supplemental protection.
If the driver and front passenger do not wear
their seat belts, it is not possible for the air
bags to provide their supplemental
protection.
In the event of other types of impacts and
impacts below air bag deployment
thresholds, the air bags will not deploy. The
driver and passengers will then be protected
to the extent possible by a properly fastened
seat belt. A properly fastened seat belt is also needed to provide the best possible
protection in a rollover.
Air bags provide additional protection; they
are not, however, a substitute for seat belts.
All vehicle occupants must fasten their seat
belts regardless of whether your vehicle is
equipped with air bags or not.
It

is important for your safety and that of your
passengers to have deployed air bags
replaced and to have any malfunctioning air
bags repaired. This will help to make sure the
air bags continue to perform their protective
function for the vehicle occupants in the
event of a crash.
Front air bags Driver's air bag
: deploys in front of the
steering wheel; front-passenger front air
bag ;

deploys in front of and above the glove
box.
The front air bags increase protection for the
driver's and front-passenger's head and
chest.
They are deployed:
R in the event of certain frontal impacts
R if the system determines that air bag
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 air bags in the
vehicle
If the vehicle overturns, the front air bags are
generally not deployed. If the system detects 42
Occupant safety
Safety

high vehicle deceleration in a longitudinal
direction, the front air bags are deployed.
If a child restraint system is installed to the
front-passenger seat and the
4
PASSENGER AIRBAG OFF indicator lamp
does not light up on the center console:
R a child restraint system without
transponders for air bag deactivation
system is installed or
R a child restraint system with transponders
is not properly installed.
Your
vehicle has adaptive, two-stage front air
bags. In the event of a collision, the air bag
control unit evaluates the vehicle
deceleration. In the first deployment stage,
the front air bag is filled with enough
propellant gas to reduce the risk of injuries.
The front air bag is fully deployed if a second
deployment threshold is exceeded within a
few milliseconds.
The deployment of the front-passenger front
air bag is also influenced by the weight
category of the front passenger, which is
determined by the Occupant Classification
System (OCS) ( Y page 45).
The lighter the passenger side occupant, the
higher the vehicle deceleration rate required
(predicted at the start of the impact) for
second-stage inflation of the front-passenger
front air bag. In the second stage, the front
air bags are inflated with the maximum
amount of propellant gas available.
The front air bags are not deployed in
situations where a low impact severity is
predicted. You will then be protected by the
fastened seat belt.
Front-passenger front air bag will only deploy
if:
R the system, based on the OCS weight
sensor readings, has detected that the
front-passenger seat is occupied.
R the 45 indicator lamp on the center
console is not lit (Y page 45).
R the air bag control unit predicts a high
impact severity. Knee bags
Driver's knee bag
:
deploys underneath the
steering column and front-passenger knee
bag ; underneath the glove box. They
deploy together with the front air bags. They
are designed to operate together with the
front air bags in frontal impacts if certain
thresholds are exceeded. The knee bags
operate at best in conjunction with correctly
positioned and fastened seat belts.
Knee bags provide increased protection for
the driver and front passenger against the risk
of:
R knee injuries
R thigh injuries
R lower leg injuries
Side impact air bags G
WARNING
Only use seat covers which have been tested
and approved by Mercedes-Benz for your
vehicle

model. Using seat covers or other seat
coverings can cause a malfunction of the side
impact air bags and/or the pelvis air bags.
Contact an authorized Mercedes-Benz Center
for availability. G
WARNING
The pressure sensors for side impact air bag
control are located in the doors. Do not
modify any components of the doors or door
trim panels including, for example, the
addition of door speakers. Occupant safety
43
Safety
Z

Improper repair work on the doors or the
modification
or addition of components to the
doors create a risk of rendering the side
impact air bags inoperative or causing
unintended air bag deployment. Work on the
doors must therefore only be performed by
qualified technicians. Contact an authorized
Mercedes-Benz Center. Front side impact air bags
: and rear side
impact air bags ; deploy next to the outer
seat cushions.
When

deployed, the side impact air bags offer
additional protection for the thorax of 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 side impact air bags 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
acceleration, e.g. in a side impact
R independently of the use of the seat belt
R independently of the front air bags
R independently of the ETDs
If the vehicle overturns, the side impact air
bags are generally not deployed. side impact
air bags are deployed if the system detects
high vehicle deceleration or acceleration in a
lateral direction and determines that side
impact air bag deployment can offer additional protection to that provided by the
seat belt.
Side impact air bags will not deploy in side
impacts which do not exceed the system's
preset deployment thresholds for lateral
acceleration/deceleration. You will then be
protected by the fastened seat belt.
The side impact air bag on the front-
passenger side is not deployed in the
following situations:
R
OCS

has detected that the front-passenger
seat is unoccupied.
R the front-passenger seat belt is not
fastened.
The side impact air bag on the front-
passenger side will deploy if the front-
passenger seat belt is fastened, regardless of
whether the front-passenger seat is occupied
or not.
Pelvis air bags G
WARNING
Only use seat covers which have been tested
and approved by Mercedes-Benz for your
vehicle

model. Using seat covers or other seat
coverings can cause a malfunction of the side
impact air bags and/or the pelvis air bags.
Contact an authorized Mercedes-Benz Center
for availability. Pelvis air bag deployment enhances the level
of

protection of the vehicle occupants on the
side of the vehicle on which the impact
occurs. 44
Occupant safety
Safety

Pelvis air bags
: deploy next to and below
the outer seat cushions. They 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
acceleration, e.g. in a side impact
R independently of the use of the seat belt
R independently of the front air bags
R independently of the ETDs
If
the vehicle overturns, the pelvis air bags are
generally not deployed. Exception: if the
system detects high vehicle deceleration or
acceleration in a lateral direction and
determines that deployment can offer
additional protection to that provided by the
seat belt.
Pelvis air bags : will not deploy in side
impacts which do not exceed the system's
preset deployment thresholds for lateral
acceleration/deceleration. You will then be
protected by the fastened seat belt.
The pelvis air bag on the front-passenger side
is not deployed in the following situations:
R OCS has detected that the front-passenger
seat is unoccupied.
R the front-passenger seat belt is not
fastened.
The pelvis air bag on the front-passenger side
will deploy if the front-passenger seat belt is
fastened, regardless of whether the front-
passenger seat is occupied or not.
Window curtain air bags Window curtain air bags
: enhance the level
of protection for the head, but not chest or
arms, of the vehicle occupants on the side of
the vehicle on which the impact occurs.
window curtain air bags : enhance the level
of protection for the head, but not chest or
arms, of the vehicle occupants on the side of
the vehicle on which the impact occurs.
The window curtain air bags are integrated
into the side of the roof frame and deploy in
the area from the A-pillar to the C-pillar.
Window curtain air bags are deployed:
R at the start of an accident with a high rate
of lateral vehicle deceleration or
acceleration, 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 window curtain air bag
deployment can offer additional 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 air bags
Window curtain air bags will not deploy in
impacts which do not exceed the system's
preset deployment thresholds for lateral
acceleration/deceleration. You will then be
protected by the fastened seat belt. Occupant Classification System
(OCS)
Method of operation G
WARNING
If the 45 indicator lamp illuminates
when
an adult or someone larger than a small
individual is in the front-passenger seat, have
the front passenger reposition himself or
herself in the seat until the 45
indicator lamp goes out.
In the event of a collision, the air bag control
unit will not allow front-passenger front air Occupant safety
45
Safety
Z

bag deployment when the OCS has classified
the front-passenger seat occupant as
weighing
as much as or less than a typical 12-
month-old child in a standard child restraint
or if the front-passenger seat is classified as
being empty.
When the OCS senses that the front-
passenger seat occupant is classified as
being up to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 45 indicator lamp will
illuminate when the engine is started and
remain illuminated, indicating that the front-
passenger front air bag is deactivated.
When the OCS senses that the front-
passenger seat is classified as being empty,
the 45 indicator lamp will illuminate
when the engine is started and remain
illuminated, indicating that the front-
passenger front air bag is deactivated.
When the OCS senses that the front-
passenger seat occupant is classified as
being heavier than the weight of a typical 12-
month-old child seated in a standard child
restraint or as being a small individual (such
as a young teenager or a small adult), the
45 indicator lamp will illuminate for
approximately 6 seconds when the engine is
started and then, depending on occupant
weight sensor readings from the front-
passenger seat, remain illuminated or go out.
With the 45 indicator lamp
illuminated, the front-passenger front air bag
is deactivated. With the 45 indicator
lamp out, the front-passenger front air bag is
activated.
When the OCS senses that the front-
passenger seat occupant is classified as an
adult or someone larger than a small
individual, the 45 indicator lamp will
illuminate for approximately 6 seconds when
the engine is started and then go out,
indicating that the front-passenger front air
bag is activated.
If the 45 indicator lamp is illuminated,
the front-passenger front air bag and the front-passenger knee bag are deactivated and
will not be deployed.
If the
45 indicator lamp is not
illuminated, the front-passenger front air bag
and the front-passenger knee bag are
activated and will be deployed:
R in the event of certain frontal impacts
R if impact exceeds a preset deployment
threshold
R independently
of the side impact air bag or
pelvis air bag
If the front-passenger front air bag is
deployed, the rate of inflation will be
influenced by:
R the rate of relevant vehicle deceleration as
assessed by the air bag control unit
R the front passenger's weight category as
identified by OCS G
WARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats

than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seats whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriate infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
The infant or child restraint must be properly
secured with the vehicle's seat belt, the seat
belt and Top Tether strap, or lower ISOFIX
child seat retaining loops and Top Tether
strap, fully in accordance with the infant or
child seat manufacturer's instructions.
Occupants, especially children, should always
sit as upright as possible, wear the seat belt
properly and use an appropriately sized infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
Children can be killed or seriously injured by
an inflating air bag. 46
Occupant safety
Safety

Note the following important information if it
is necessary to carry a child on the front-
passenger seat:
R
Your vehicle is equipped with air bag
technology designed to deactivate the
front-passenger
front air bag and the front-
passenger knee bag in your vehicle when
the system senses the weight of a typical
12-month-old child or less along with the
weight of a standard appropriate child
restraint on the front-passenger seat.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates in a collision which
could occur under some circumstances,
even with the air bag technology installed
in your vehicle. The only means to eliminate
this risk completely is never to place a child
in a rear-facing child restraint in the front-
passenger seat. We therefore strongly
recommend that you always place a child
in a rear-facing child restraint on the rear
seat.
R If you install a rear-facing child restraint on
the front-passenger seat, make sure the
45 indicator lamp is illuminated,
indicating that the front-passenger front air
bag and front-passenger knee bag are
deactivated. Should the 45
indicator lamp not illuminate or go out while
the restraint is installed, please check
installation. Periodically check the
45 indicator lamp while driving to
make sure that the 45 indicator
lamp is illuminated. If the 45
indicator lamp goes out or remains out, do
not transport a child on the front-passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat could be seriously
injured or even killed if the front-passenger
front air bag is deployed. R
If you place a child in a forward-facing child
restraint on the front-passenger seat:
- move the seat as far back as possible
- use the proper child restraint
recommended for the age, size and
weight of the child
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
R For children larger than the typical 12-
month-old child, the front-passenger front
air bag and the front-passenger knee bag
may or may not be activated. G
WARNING
If the red 6 SRS warning lamp in the
instrument cluster and the 45
indicator lamp light up simultaneously, the
OCS is malfunctioning. The front passenger
front

air bag and the front passenger knee bag
will be deactivated in this case. Have the
system checked by qualified technicians as
soon as possible. Contact an authorized
Mercedes-Benz Center.
Only have the seat repaired or replaced at an
authorized Mercedes-Benz Center.
In order to ensure proper operation of the air
bag system and OCS:
R Sit with the seat belt properly fastened in a
position that is as upright as possible with
your back against the seat backrest.
R When seated, a passenger should not
position him/herself in such a way as to
cause the passenger's weight to be lifted
from the seat cushion as this may result in
the OCS being unable to correctly
approximate the passenger's weight
category.
R Read and observe all warnings in this
chapter. Occupant safety
47
Safety Z

If the SmartKey has been removed from the
ignition lock or is in position 0, the
45 indicator lamp
: does not light
up.
The Occupant Classification System (OCS)
categorizes the occupant on the front-
passenger
seat by means of a weight sensor.
The front-passenger front air bag and the
front-passenger knee bag are deactivated
automatically for certain weight categories.
The 45 indicator lamp shows you the
current status. If the 45 indicator
lamp lights up, the front-passenger air bag
and the front-passenger knee bag are
disabled.
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
To be classified correctly, the front passenger
must sit:
R with the seat belt fastened correctly
R in a position that is as upright as possible
with their back against the seat backrest
R with their feet on the floor
The OCS weight sensor reading is affected if
the occupant's weight is transferred, e.g. by
leaning on the armrest.
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. For safety reasons, Mercedes-Benz
recommends that you only use seat
accessories that have been approved by
Mercedes-Benz.
Both the driver and the front passenger
should always observe the
45
indicator lamp to determine whether or not
the front passenger is positioned correctly.
Also observe the air bag display messages,
which appear in the instrument cluster
(Y page 235).
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
will also deploy.
The OCS may have detected that the seat:
R is empty or occupied by the weight of a
typical child up to twelve months old,
seated in a child restraint system
R is

occupied by a small individual, such as a
young teenager or a small adult
R is occupied by a child in a child restraint
system whose weight is greater than that
of a typical twelve month old child.
These are examples of when the OCS
deactivates the front-passenger front air bag
and front-passenger knee bag. Deactivation
takes place although the collision fulfills the
criteria for deploying the driver's air bag.
For further information, see "Air bag display
messages" ( Y page 235).
System self-test G
WARNING
If the 4 5 indicator lamp does not
illuminate,
the system is not functioning. You
must contact an authorized Mercedes-Benz
Center before seating any child on the front
passenger seat. G
WARNING
Never place anything between seat cushion
and
child seat (e.g. a pillow), since it reduces
the effectiveness of the OCS. The underside
and rear side child restraint system must be
placed entirely on the seat cushion and the 48
Occupant safety
Safety