MERCEDES-BENZ GLA-Class 2015 X156 Workshop Manual
Manufacturer: MERCEDES-BENZ, Model Year: 2015, Model line: GLA-Class, Model: MERCEDES-BENZ GLA-Class 2015 X156Pages: 374, PDF Size: 6.85 MB
Page 51 of 374
Objects in the vehicle interior may pre-
vent the air bag from functioning cor-
rectly. 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.
R no 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.
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 objectsto 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
any more. 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
0043deploys in front of the
steering wheel; front-passenger front air
bag 0044deploys in front of and above the glove
box.
When deployed, the front air bags offer addi- tional head and thorax protection for the
occupants in the front seats.
The PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps
inform you about the status of the front-
passenger front air bag (Y page 43).
Front-passenger front air bag 0044will only
deploy if:
R the system, based on the OCS weight sen-
sor readings, detects that the front-
passenger seat is occupied (Y page 51).
The PASSENGER AIR BAG ON indicator
lamp is lit (Y page 51)
R the restraint system control unit predicts a
high accident severity
Knee bags Occupant safety
49Safety Z
Page 52 of 374
Driver's knee bag
0043deploys under the steer-
ing column and front-passenger knee bag 0044
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 could restrict or even
prevent the deployment of the air bags inte-
grated into the seats. Consequently, the air
bags cannot protect vehicle occupants as
they are designed to do. In addition, the func- tion of the Occupant Classification System
(OCS) could be restricted. 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. Front side impact air bags
0043and rear side
impact air bags 0044deploy next to the outer
bolster of the seat backrest.
When deployed, the side impact air bag offers additional thorax protection. It also offers
additional pelvis protection for occupants in
the front seats. 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 (front) deploys in the follow-
ing situations:
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 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
0043are 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
(Y page 56). 50
Occupant safetySafety
Page 53 of 374
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 and front-passenger
knee bag are either enabled or deactivated.
The system does not deactivate:
R the side impact air bag
R the window curtain air bag
R the Emergency Tensioning Devices
Prerequisites 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 possi-
ble
If the front passenger does not observe these conditions, OCS may produce a false classi-
fication, 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. cushions. The entire base of the
child restraint system must always rest on the
seat cushion of the front-passenger seat. The
backrest of the forwards-facing child restraint
system must, as far as possible, be resting on the backrest of the front-passenger seat.
The child restraint system must not touch the roof or be put under strain by the head
restraint. Adjust the angle of the seat back- 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) 0043
PASSENGER AIR BAG ON indicator lamp
0044 PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front air bag is deactivated or
enabled.
X Press 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.
R PASSENGER AIR BAG ON 0043lights 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.
R PASSENGER AIR BAG OFF 0044lights up: the
front-passenger front air bag is deactiva-
ted. It will then not be deployed in the event
of an accident. Occupant safety
51Safety Z
Page 54 of 374
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 (Y page 233). 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. 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 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. 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"
(Y page 55). 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, in the event of an
accident, the child could:
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 ON is lit up
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 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 outlet and the front-
passenger seat accordingly. Always observe
the child restraint system manufacturer's
installation instructions.
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 12 months old in a standard
child restraint system, the PASSENGER AIR 52
Occupant safetySafety
Page 55 of 374
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 in the case of a 12-month-old child in a
standard child restraint system, the
PASSENGER AIR BAG ON can light up per-
manently after the system self-test. This
indicates that the front-passenger front air bag 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 restraint system on a suitable
rear seat.
R the 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 siton 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 a stature correspond-
ing to that of an adult, the PASSENGER AIR BAG ON indicator lamp lights up after the
system self-test and remains lit. 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 vehi-
cle" (Y page 58).
When OCS is malfunctioning, the red 0075
restraint system warning lamp in the instru-
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 an accident. 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 G
DANGER
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 notbe 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
DANGER
If the PASSENGER AIR BAG OFF indicator
lamp remains lit after the system self-test, the front-passenger front air bag is disabled. It willnot be deployed in the event of an accident. In
this case, the front-passenger front air bag
cannot perform its intended protective func- Occupant safety
53Safety
Z
Page 56 of 374
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:
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
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. G
WARNING
Objects between the seat surface and the
child restraint system could affect OCS oper- ation. This could result in the front-passengerair 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 forwards- 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 or PASSENGER AIR BAG ON
indicator lamp display the status of the front-
passenger front air bag (Y page 51).
For more information about the OCS, see
"Problems with the Occupant Classification
System" (Y page 55). 54
Occupant safetySafety
Page 57 of 374
Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Y
page 53).Problem
Possible causes/consequences and
0050
0050Solutions 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.
X Make sure the conditions for a correct classification of the per-
son on the front-passenger seat are met (Y page 51).
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 by the
weight of a child up
to 12 months old in a
child restraint sys-
tem 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 pos- sible against the backrest of the front-passenger seat. If nec-
essary, 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
accordingly.
X Make sure that no objects are applying additional weight onto
the seat.
X 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 child restraint system on the front-passenger seat. It is
recommended that you install the restraint system on a suitable
rear seat.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. Occupant safety
55Safety Z
Page 58 of 374
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
bags continue to perform their protective
function for the vehicle occupants in the
event of a crash. G
WARNING
Pyrotechnic Emergency Tensioning Devices
that have been deployed 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.
Therefore, have pyrotechnic Emergency Ten-
sioning Devices which have been triggered
immediately replaced at a qualified specialist workshop.
If Emergency Tensioning Devices or air bags
are deployed, you will hear a bang, and a small
amount of powder may also be released. The
0075 restraint system warning lamp lights up.
Only in rare cases will the bang affect your
hearing. The powder that is released gener-
ally does not constitute a health hazard, but it
may cause short-term breathing difficulties in people with asthma or other respiratory prob-
lems. To avoid this, you may wish to get out of
the vehicle or open the windows as soon as it is safe to do so.
Air bags and pyrotechnic Emergency Tension-
ing Devices (ETDs) contain perchlorate mate- rial, which may require special handling and
regard for the environment. National guide-
lines 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 impor-
tant physical data relating to vehicle deceler- ation or acceleration, such as:
R duration
R direction
R intensity
Based on the evaluation of this data, the
restraint system control unit deploys the
Emergency Tensioning Devices during a fron- tal or rear collision.
An Emergency Tensioning Device can only be
deployed, if:
R the ignition is switched on
R the components of the restraint system are
operational; see "Restraint system warning
lamp" (Y page 43)
R the belt tongue is engaged in the buckle on
the respective front-passenger seat
The Emergency Tensioning Devices in the
rear compartment are deployed independ-
ently of the lock status of the seat belts. 56
Occupant safetySafety
Page 59 of 374
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 as well as driver's and front-
passenger knee bags
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 ON indi-
cator lamp is lit. Observe the information on
the PASSENGER AIR BAG indicator lamps
(Y page 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 deployment 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 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 accelera-
tion and the direction of the force are essen- tially determined by:
R the distribution of forces during the colli-
sion
R the collision angle
R the deformation characteristics of the vehi-
cle
R the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an 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 restraint system control unit detects a
side impact or that the vehicle is rolling over, the relevant restraint system components areactivated independently of one another
depending on the apparent type of accident.
If the system determines a need for additional
protection for the vehicle occupants, the
Emergency Tensioning Devices are deployed.
R Side 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 in the fol-
lowing situations:
- 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 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 acci-
dent. The different air bag systems work
independently of each other. Occupant safety
57Safety Z
Page 60 of 374
How the air bag system works is deter-
mined by the severity of the accident detec- ted, especially the vehicle deceleration or
acceleration and the apparent type of acci-dent:
R frontal collision
R side impact
R rollover Automatic measures after an acci-
dent
Immediately after an accident, the following
measures are implemented, depending on
the type and severity of the impact:
R the hazard warning lamps are activated
R the emergency lighting is activated
R the vehicle doors are unlocked
R the front side windows are lowered
R the engine is switched off
R the fuel supply is cut off
R vehicles with mbrace: automatic emer-
gency call Children in the vehicle
Important safety notes
Accident statistics show that children
secured in the rear seats are safer than chil-
dren secured in the front-passenger seat. For this reason, Mercedes-Benz strongly advises
that you install a child restraint system on a
rear seat. Children are generally better pro-
tected there.
If a child younger than 12 years and under 5 ft
(1.50 m) in height is traveling in the vehicle:
R always secure the child in a child restraint
system suitable for Mercedes-Benz vehi-
cles. The child restraint system must be
appropriate 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 classifica-
tion system (OCS)" (Y page 51) 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 childrestraint 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 sit- ting properly. Particular attention must be
paid to children. 58
Children in the vehicleSafety