MERCEDES-BENZ GLC-Class 2016 X253 Workshop Manual

ROnly hold the steering wheel on the out-
side. This allows the air bag to be fully
deployed.
RAlways lean against the backrest while driv-
ing. Do not lean forwards or lean against
the door or side window. You may other-
wise be in the deployment area of the air
bags.
RAlways keep your feet in the footwell in
front of the seat. Do not put your feet on the
dashboard, for example. Your feet may oth-
erwise be in the deployment area of the air
bag.
RFor this reason, always secure persons less
than 5 ft (1.50 m) tall in suitable restraint
systems. Up to this height, the seat belt
cannot be worn correctly.
If a child is traveling in your vehicle, also
observe the following notes:
RAlways secure children under twelve years
of age and less than 5 ft (1.50 m) tall in
suitable child restraint systems.
RChild restraint systems should be installed
on the rear seats.
ROnly secure a child in a rearward-facing
child restraint 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 .
RAlways observe the instructions and safety notes on the "Occupant Classification Sys-
tem (OCS)" (
Ypage 51) and on "Children
in the vehicle" (
Ypage 60) in addition to
the child restraint system manufacturer's
installation instructions. Objects in the vehicle interior may pre-
vent 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:
Rthere are no people, animals or objects
between the vehicle occupants and an air
bag.
Rthere are no objects between the seat, door
and B-pillar.
Rno hard objects, e.g. coat hangers, hang on
the grab handles or coat hooks.
Rno accessories, such as cup holders, are
attached to the vehicle within the deploy-
ment area of an air bag, e.g. to doors, side
windows, rear side trim or side walls.
Rno heavy, sharp-edged or fragile objects
are in the pockets of your clothing. Store
such objects in a suitabl
e place.
GWARNING
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.
GWARNING
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.
Occupant safety49
Safety
Z

Front air bags
Driver's air bag:deploys in front of the
steering wheel. Front-passenger front air
bag ;deplo ysinfront of and above the glove
box.
When deployed, the front air bags offer addi-
tional head and thorax protection for the
occupants inthe front seats.
The PASS ENGER AIR BAG OFF and
PASS ENGER AIR BAG ON indicator lamps
inform you about the status of the front-
passenger air bag (
Ypage 43).
The front-passenger front air bag will only
deplo y if:
Rthe system, based on the OCS weight sen-
sor readings, detects that the front-
passenger seat is occupied (
Ypage 51).
The PASS ENGER AIR BAG ON indicator
lamp is lit(
Ypage 52)
Rthe restraint system control unit predicts a
high acc ident severity
Driver's knee bag
Driver's knee bag :deploys under the steer-
ing column. The driver's knee bag istriggered
together with the front air bag.
The driver's knee bag offers additional thigh,
knee and lower leg protection for the occu-
pant inthe driver's seat.
Side impact air bags
GWARNIN G
Unsuitable seat cover scould restrict or eve n
preven tth edeploymen tof th eair bags inte-
grated int oth eseats. Consequently, th eair
bags canno tprotect vehicl eoccupant sas
they are designed to do. In addition ,th efunc-
tion of th eOccupant Classification Syste m
(OCS )could be restricted. This poses an
increased ris kof injury or eve nfatal injury.
You should only use seat cover sthat have
been approve dfor th erespective seat by
Mercedes-Benz.
Front side impact air bags :and rear side
impact air bags ;deploy next to the outer
bols ter of the seat backrest.
When deployed, the side impact air bag offers
additional thorax protection. Ho wever,itdoes
not protect the:
Rhead
Rneck
Rarms
In the event of a side impact, the side impact
air bag isdeployed on the side on which the
impact occurs.
50Occupant safety
Safety

The side impact air bag on the front-
passenger side (front) deploys under the fol-
lowing conditions:
Rthe OCS system detects that the front-
passenger seat is occupied or
Rthe 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 acci-
dent situation occurs. In this case, deploy-
ment is independent of whether the front-
passenger seat is occupied or not.
Window curtain air bags
Window curtain air bags :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 cur-
tain 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
(
Ypage 57).
Occupant Classification System
(OCS)
Introduction
The Occupant Classification System (OCS)
categorizes the person in the front-passenger
seat. Depending on that result, the front-
passenger front air bag is either enabled or
deactivated.
The system does not disable:
Rthe side impact air bag
Rthe window curtain air bag
Rthe Emergency Tensioning Devices
Prerequisites
To be classified correctly, the front passenger
must sit:
Rwith the seat belt fastened correctly
Rin an almost upright position with their
back against the seat backrest
Rwith their feet resting on the floor, if possi-
ble
If the front passenger does not observe these
conditions, OCS may produce a false classi-
fication, e.g. because the front passenger:
Rtransfers their weight by supporting them-
selves on a vehicle armrest
Rsits 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. cushions. Fully retract the seat
cushion length. 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 back-
Occupant safety51
Safety
Z

rest and the head restraint position accord-
ingly.
Only then can OCS be guaranteed to function
correctly. Always observe the child restraint
system manufacturer's installation instruc-
tions.
Occupant Classification System opera-
tion (OCS)
:PASSENGER AIR BAG ON indicator lamp
;PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front air bag is deactivated or
enabled.
XPress the Start/Stop button once or twice,
or turn the SmartKey to position 1or 2in
the ignition lock.
The system carries out self-diagnostics.
The PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps
must light up simultaneously for approx-
imately six seconds.
The indicator lamps display the status of the
front-passenger front air bag.
RPASSENGER AIR BAG ON lights up: 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.
RPASSENGER AIR BAG OFF lights up: the
front-passenger front air bag is deactiva-
ted. It will then not be deployed in the event of an accident. If the status of the front-passenger front air
bag changes while the vehicle is in motion, an
air bag display message appears in the instru-
ment cluster (
Ypage 271). When the front-
passenger seat is occupied, always pay atten-
tion to the PASSENGER AIR BAG ON and
PASSENGER AIR BAG OFF indicator lamps. Be
aware of the status of the front-passenger
front air bag both before and during the jour-
ney.
GWARNING
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:
Rthe 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
Rthe front-passenger seat has been moved
back as far back as possible.
Rthe 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.
GWARNING
If you secure a child in a rearward-facing child
restraint system on the front-passenger seat
and the PASSENGER AIR BAG ON indicator
lamp is lit up, the front-passenger front air bag may deploy in an accident. The child could be
struck by the air bag. This poses an increased
risk of injury or even fatal injury.
52Occupant safety
Safety

Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
If the PASSENGER AIR BAG OFF indicator
lamp remains off and/or the PASSENGER AIR
BAG ON indicator lamp lights up, do not install
a rearward-facing child restraint system on
the front-passenger seat. You can find more
information on OCS under "Problems with the
Occupant Classification System"
(
Ypage 56).
GWARNING
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, in the event of an
accident, the child could:
Rcome into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example
Rbe struck by the air bag if the PASSENGER
AIR BAG ON is lit up
This poses an increased risk of injury or even fatal injury.
Always move the front-passenger seat as far
back as possible and fully retract the seat
cushion length. 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 downwards from the vehicle belt sash
guide. If necessary, adjust the vehicle belt
sash guide and the front-passenger seat
accordingly. Always observe the child
restraint system manufacturer's installation
instructions.
If OCS determines that:
Rthe front-passenger seat is unoccupied, thePASSENGER 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.
Rthe front-passenger seat is occupied by a
child of up to twelve months old, in a stand-
ard child restraint system, 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.
But even in the case of a twelve-month-old
child, in a standard child restraint system,
the PASSENGER AIR BAG ON can light up
permanently after the system self-test. This
indicates that the front-passenger front airbag is activated. The result of the classifi-
cation is dependent on, among other fac-
tors, the child restraint system and the
child's stature. It is recommended that you
install the child restraint system on a suit-
able rear seat.
Rthe front-passenger seat is occupied by a
person of smaller stature (e.g. a teenager
or small adult), either the PASSENGER AIR
BAG ON or PASSENGER AIR BAG OFF indi-
cator lamp lights up and remains lit after
the system self-test depending on the
result of the classification.
-If the PASSENGER AIR BAG ON indicator
lamp lights up, move the front-passenger
seat as far back as possible. Alterna-
tively, a person 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.
Rthe front-passenger seat is occupied by an
adult or a person of adult stature, the
PASSENGER AIR BAG ON indicator lamp
lights up after the system self-test and
remains lit. This indicates 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 vehi- cle" (
Ypage 60).
When OCS is malfunctioning, the red 6
restraint system warning lamp in the instru-
Occupant safety53
Safety
Z

ment cluster and the PASSENGER AIR BAG
OFF indicator lamp light up simultaneously.
The front-passenger front air bag is deactiva-
ted in this case and does not deploy during anaccident. Have the system checked by quali-
fied technicians as soon as possible. Consult
an authorized Mercedes-Benz Center. The
front-passenger seat should only be repaired
at an authorized Mercedes-Benz Center.
If the front-passenger seat, the seat cover or
the seat cushion is damaged, have the nec-
essary repair work carried out at an author-
ized Mercedes-Benz Center.
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
System (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
GDANGER
If both the PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps do
not light up during the system self-test, the
system is malfunctioning. The front-
passenger front air bag might be triggered
unintentionally or might not be triggered at all
in the event of an accident with high deceler-
ation. 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.
GDANGER
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.
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:
Rthe 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
Rthe person is seated properly with a cor-
rectly fastened seatbelt
Rthe front-passenger seat has been moved
back 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.
GWARNING
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
54Occupant safety
Safety

child restraint system manufacturer's instal-
lation instructions.
After the system self-test, the PASSENGER
AIR BAG OFF or PASSENGER AIR BAG ON
indicator lamp displays the status of the front-
passenger front air bag (
Ypage 52).
For more information about the OCS, see
"Problems with the Occupant Classification
System" (
Ypage 56).
Occupant safety55
Safety
Z

Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Ypage 54).
ProblemPossible causes/consequences andMSolutions
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
person of a stature cor-
responding to that of an
adult.The classification of the person on the front-passenger seat is
incorrect.
XMake sure the conditions for a correct classification of the per-
son on the front-passenger seat are met (
Ypage 51).
XIf the PASSENGER AIR BAG OFF indicator lamp remains lit, the
front-passenger seat may not be used.
XHave 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:
Runoccupied
Roccupied with the
weight of a child up
to twelve months old
in a child restraint
system
OCS is malfunctioning.
XMake sure there is nothing between the seat cushion and the
child seat.
XMake 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 pos-
sible against the backrest of the front-passenger seat. If nec-
essary, adjust the position of the front-passenger seat.
XMake sure that the seat cushion length is fully retracted.
XWhen 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.
XCheck 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
accordingly.
XMake sure that no objects are applying additional weight onto
the seat.
XIf the PASSENGER AIR BAG OFF indicator lamp remains off and/
or the PASSENGER AIR BAG ON indicator lamp lights up, do notinstall a child restraint system on the front-passenger seat. It is
recommended that you install the child restraint system on a
suitable rear seat.
XHave OCS checked as soon as possible at an authorized
Mercedes-Benz Center.
56Occupant safety
Safety

Deployment of Emergency Tensioning
Devicesan dair bags
Important safet ynotes
GWARNING
The air bag parts are hot after an air bag has
bee ndeployed .There is aris kof injury.
Do no ttouch th eair bag parts .Hav e a
deployed air bag replaced at aqualified spe -
cialis tworkshop as soo nas possible.
GWARNING
A deployed air bag no longer offers any pro -
tection and canno tprovid eth eintended pro -
tection in an accident. There is an increase d
ris kof injury.
Hav eth evehicle towed to aqualified special-
ist workshop in order to hav e adeployed air
bag replaced.
It is important fo ryour safet yand that of your
passenger to hav edeployed air bags replaced
and to hav eany malfunctionin gair bags
repaired. Thi swill help to mak esur eth eair
bags continue to perform their protective
function fo rth evehicle occupant sin th e
event of acrash .
GWARNING
Pyrotechnic Emergency Tensioning Devices
that hav ebee ndeployed are no longer opera-
tional and are unable to perform their inten-
ded protective function .Thi sposes an
increase dris kof injury or eve nfatal injury.
Therefore, hav epyrotechni cEmergency Ten -
sioning Devices whic hhav ebee ntriggere d
immediately replaced at aqualified specialis t
workshop .
An electric moto ris used by PRE-SAF E®to
trigger th etightenin gof th eseat belt in haz -
ardous situations. Thi sprocedur eis reversi-
ble.
If Emergency Tensioning Devices are trig-
gered or air bags are deployed ,you will hear a
bang, and asmall amount of powder may also be released. The
6restrain tsystem warn -
in g lamp lights up.
Only in rar ecases will th eban gaffec tyour
hearing. The powder that is release dgener-
ally doe sno tconstitute ahealth hazard ,but it
may caus eshort-term breathin gdifficulties in
people wit hasthm aor other respirator yprob-
lems. To avoid this, you may wish to get out of
th evehicle or ope nth ewindows as soo nas it
is saf eto do so.
Ai rbags and pyrotechni cEmergency Tension-
in gDevices (ETDs) contain perchlorat emate-
rial ,whic hma
y require special handlin gand
regard fo rth eenvironment. National guide-
lines mus tbe observed durin gdisposal. In
California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm .
Method of operation
Duringth efirst stage of acollision ,th e
restrain tsystem contro luni tevaluates impor -
tant physical dat arelatin gto vehicle deceler -
ation or acceleration ,suc has:
Rduration
Rdirection
Rintensit y
Based on th eevaluation of this data, th e
restrain tsystem contro luni ttriggers th e
Emergency Tensioning Devices durin g afron -
ta lor rea rcollision .
An Emergency Tensioning Devic ecan only be
triggered, if:
Rth eignition is switched on
Rth ecomponent sof th erestrain tsystem are
operational; see "Restrain tsystem warnin g
lamp " (
Ypage 43)
Rthebelt tongue is engage din th ebuckl eon
th erespective front-passenger seat
The Emergency Tensioning Devices in th e
rea rcompartmen tare triggere dindepend -
entl yof th eloc kstatus of th eseat belts.
If th erestrain tsystem contro luni tdetects a
more severe accident, further component sof
Occupant safety57
Safety
Z

the restraint system are activated independ-
ently of each other in certain frontal collision
situations:
RFront air bags and driver's knee bag
RWindow 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 ON indi-
cator lamp is lit. Observe the information on
the PASSENGER AIR BAG indicator lamps
(
Ypage 43).
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 pro-
pellant gas if a second deployment threshold
is reached within a few milliseconds.
The activation threshold of the Emergency
Tensioning Devices and the air bag are deter-
mined by evaluating the rate of vehicle decel-
eration or acceleration which occurs at vari-
ous points in the vehicle. This proce
ss is pre-
emptive in nature. Deployment should take
place in good time at the start of the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
Rthe distribution of forces during the colli-
sion
Rthe collision angle
Rthe deformation characteristics of the vehi-
cle
Rthe 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 air bag.
Nor do they provide an indication of air bag
deployment. The vehicle can be deformed considerably,
without an air bag being deployed. This is the
case if only parts which are relatively easily
deformed are affected and the rate of decel-
eration is not high. Conversely, air bags may
be deployed even though the vehicle suffers
only minor deformation. This is the case if, for
example, very rigid vehicle parts such as lon-gitudinal body members are hit, and sufficient
deceleration occurs as a result.
If the control unit of the restra int s
ystem
detects a side impact or a vehicle rollover, the
relevant components of the restraint system
are activated separately depending on the
anticipated type of accident.
RSide impact air bags on the side of impact, independently of the Emergency Tension-
ing Device and the use of the seat belt on
the driver's seat and outer seats in the sec-
ond row
The side impact air bag on the front-
passenger side (front) deploys under the
following conditions:
-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
RWindow 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
RFront Emergency Tensioning Devices, if the
system determines that deployment can
offer additional protection for the vehicle
occupants in this situation
RRear Emergency Tensioning Devices in cer-
tain situations if the vehicle rolls over
RWindow curtain air bags on the driver's and
front-passenger side in certain situations
when the vehicle rolls over, if the system
determ ines th
at deployment can offer addi-
tional protection to that provided by the
seat belt
iNot all air bags are deployed in an acci-
dent. The different air bag systems work
independently of each other.
58Occupant safety
Safety