MERCEDES-BENZ A-CLASS HATCHBACK 2015 Workshop Manual
Manufacturer: MERCEDES-BENZ, Model Year: 2015, Model line: A-CLASS HATCHBACK, Model: MERCEDES-BENZ A-CLASS HATCHBACK 2015Pages: 417, PDF Size: 11.91 MB
Page 51 of 417
Driver's airbag
:deploys in front of the
steering wheel. Front-passenger front air-
bag ;deploys in front of and above the glove
compartment.
When deployed, the front airbags 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 airbag (Y page 41).
The front-passenger front airbag will only
deploy if:
R the automatic front-passenger front airbag
deactivation system has detected that the
front-passenger seat is occupied
(Y page 49). The PASSENGER AIR BAG
ON indicator lamp is lit (Y page 50)
R the restraint system control unit predicts a
high accident severity
Driver's kneebag Driver's kneebag
:deploys under the steer-
ing column. The driver's kneebag is triggered
together with the front airbags.
The driver's kneebag offers additional thigh,
knee and lower leg protection for the occu-
pant in the driver's seat.
i The driver's kneebag is only available in
certain countries.
Sidebags G
WARNING
Unsuitable seat covers can obstruct or pre-
vent the deployment of the airbags integrated into the seats. Consequently, the airbags can-
not protect vehicle occupants as they are
designed to do. In addition, the function of the automatic front-passenger front airbag deac-
tivation system 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 corresponding seats by Mercedes-Benz. Front sidebags
:and rear sidebags ;
deploy next to the outer bolster of the seat
backrest.
When deployed, the sidebag offers additional thorax protection. It also offers additional pel-
vis protection for occupants in the front
seats. However, it does not protect the:
R head
R neck
R arms 48
Occupant safetySafety
Page 52 of 417
In the event of a side impact, the sidebag is
deployed on the side on which the impact
occurs.
Vehicles with the automatic front-passenger
airbag deactivation system: the sidebag on
the front-passenger side deploys under the
following conditions:
R an occupant is detected on the front-
passenger seat 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 sidebag on the front-passenger
side deploys if an appropriate accident situa- tion occurs. In this case, deployment is inde- pendent of whether the front-passenger seat
is occupied or not.
Windowbags Windowbags
:are integrated into the side
of the roof frame and deploy in the area from
the A-pillar to the C-pillar.
When deployed, the windowbag 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 windowbag
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 windowbag may be deployed in
other accident situations (Y page 55). Automatic front-passenger front air-
bag deactivation
Introduction In order to recognise a child restraint system
on the front-passenger seat, the automatic
front-passenger front airbag deactivation sys- tem categorises the person in the front-
passenger seat. Depending on that result, the
front-passenger front airbag is either enabled or disabled. If a rearward-facing child
restraint system is fitted to the front-
passenger seat, the PASSENGER AIR BAG
OFF indicator lamp must light up after the
system self-test and remain lit. The front-
passenger front airbag is disabled.
The system does not disable:
R the sidebag
R the windowbag
R the seat belt tensioner
Make sure that your vehicle is equipped with
the automatic front-passenger front airbag
deactivation system (Y page 61). If this is
not the case, always install a child restraint
system on a suitable rear seat (Y page 62).
If it is absolutely necessary to install a child
restraint system on the front-passenger seat,
be sure to observe the correct positioning of
the child restraint system. Never place
objects under or behind the child restraint
system, e.g. a cushion. 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, as far as possible, be resting onthe 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 backrest and the
head restraint position accordingly. Only then is the correct function of the automatic front- passenger front airbag deactivation system
guaranteed. Always observe the information
on suitable positioning of the child restraint
system (Y page 62) in addition to the child Occupant safety
49Safety Z
Page 53 of 417
restraint system manufacturer's installation
instructions.
Operation of automatic front-passenger
front airbag deactivation :
PASSENGER AIR BAG ON indicator lamp
; PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front airbag is disabled or
enabled.
X Press the Start/Stop button once or twice,
or turn the key to position 1or 2in the
ignition lock.
The system carries out a self-diagnosis.
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 airbag:
R PASSENGER AIR BAG ON lights up: the
front-passenger front airbag is enabled. If,
in the event of an accident, all deployment
criteria are met, the front-passenger front
airbag is deployed.
R PASSENGER AIR BAG OFF lights up: the
front-passenger front airbag is disabled. 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
airbag display message appears in the instru-
ment cluster (Y page 270). 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 airbag both before and during the jour-
ney.
If a person sits in the passenger seat, they
must be:
R seated 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, the automatic front-passenger
front airbag deactivation system may be influ-
enced, 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
The front-passenger front airbag may be dis-
abled by mistake as a result of these or similar actions. In this case, the PASSENGER AIR
BAG OFF indicator lamp lights up perma-
nently. The front-passenger front airbag doesnot then deploy during an accident. G
WARNING
If the PASSENGER AIRBAG OFF indicator lamp is lit, the front-passenger front airbag is disa-
bled. It will not be deployed in the event of an
accident and cannot perform its intended pro-
tective 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 make sure that:
R the classification of the person in the front-
passenger seat is correct and that the front-
passenger front airbag is enabled or disa- 50
Occupant safetySafety
Page 54 of 417
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 airbag is correct. G
WARNING
If you secure a child on the co-driver's seat in a rearward-facing child restraint system and
the PASSENGER AIR BAG ON indicator lamp
lights up, the co-driver's airbag could be
deployed in the event of an accident. The childcould be struck by the airbag. There is an
increased risk of injury, possibly even fatal.
In this case, always ensure that the co-driver's
airbag is disabled. The PASSENGER AIRBAG
OFF indicator lamp must light up.
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. Further information can be found under "Problems with the auto-matic front-passenger front airbag deactiva-
tion system" (Y page 54). 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 airbag if the PASSENGER
AIR BAG ON indicator lamp is lit
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 outlet to the shoulder belt
guide on the child restraint system. The shoul-
der 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 information about suitable posi-
tioning of the child restraint system in this
Owner's Manual as well as the child restraint system manufacturer's installation instruc-
tions.
If the automatic front-passenger front airbag
deactivation system detects 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 airbag is disabled.
R the front-passenger seat is occupied by a
child in a rearward-facing child restraint
system, the PASSENGER AIR BAG OFF indi-
cator lamp lights up after the system self-
test and remains lit. This indicates that the
front-passenger front airbag is disabled.
But in the case of a child in a rearward-
facing child restraint, the PASSENGER AIR
BAG ON indicator lamp can light up after
the system self-test and remain lit. This
indicates that the front-passenger front air-
bag is enabled. The result of the classifica- tion is dependent on, among other factors, the child restraint system and the child's
build. It is recommended that you fit the
child restraint system to a suitable rear
seat.
R the front-passenger seat is occupied by a
child in a forward-facing child restraint sys-
tem, either the PASSENGER AIR BAG ON or
PASSENGER AIR BAG OFF indicator lamp
lights up and remains lit after the system
self-test depending on the result of the
classification. The result of the classifica-
tion is dependent on, among other factors,
the child restraint system and the child's
build. Occupant safety
51Safety Z
Page 55 of 417
Move the front-passenger seat as far back
as possible. Always observe the informa-
tion in "Child restraint systems on the front- passenger seat" (Y page 61) and in "Suit-
able positioning of the child restraint sys-
tem" (Y page 62). Alternatively, you can
fit the child restraint system to a suitable
rear seat.
R the front-passenger seat is occupied by a
person with a smaller build (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 with a small build can sit
on a rear seat.
- if the PASSENGER AIR BAG OFF indicator
lamp is lit, a person with a smaller build
should not use the front-passenger seat.
R the front-passenger seat is occupied by an
adult or a person with a build 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 airbag
is enabled.
If children are travelling in the vehicle, be sure to observe the notes on "Children in the vehi-
cle" (Y page 57).
If the automatic front-passenger front airbag
deactivation system is malfunctioning, the
red 6 restraint system warning lamp in
the instrument cluster and the PASSENGER
AIR BAG OFF indicator lamp light up simulta-
neously. The front-passenger front airbag is
disabled in this case and does not deploy dur- ing an accident. Have the system checked as
soon as possible by qualified technicians.
Consult a Mercedes-Benz Service Centre. The
front-passenger seat should only be repaired at a Mercedes-Benz Service Centre. If the front-passenger seat, the seat cover or
the seat cushion is damaged, have the nec-
essary repair work carried out at a Mercedes- Benz Service Centre.
For safety reasons, Mercedes-Benz recom-
mends that you only use a child restraint sys-
tem which has been tested and approved by
Mercedes-Benz in combination with the auto- matic front-passenger front airbag deactiva-
tion system.
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 airbag 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 auto-
matic front-passenger front airbag deactiva-
tion system checked and repaired immedi-
ately at a qualified specialist workshop. G
WARNING
If the PASSENGER AIRBAG OFF indicator lamp remains lit after the system self-test, the
front-passenger front airbag is disabled. It willnot be deployed in the event of an accident. In
this case, the front-passenger front airbag
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. 52
Occupant safetySafety
Page 56 of 417
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 airbag 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 seat belt.
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 automatic front-
passenger front airbag deactivation system
checked and repaired immediately at a quali-
fied specialist workshop. G
WARNING
Objects between the seat surface and the
child restraint system could affect the func-
tion of the automatic front-passenger front
airbag deactivation system. This could result
in the front-passenger front airbag not func-
tioning 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
rear reclining 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 then shows the status of the
co-driver's front airbag (Y page 50).
Further information can be obtained under
"Problems with the automatic co-driver's front airbag deactivation system"
(Y
page 54). Occupant safety
53Safety Z
Page 57 of 417
Problems with automatic front-passenger front airbag deactivation
Be sure to observe the notes on "System self-test" (Y
page 52).Problem
Possible causes/consequences and
M
MSolutions 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 with a build cor-responding to that of an
adult. The classification of the person on the front-passenger seat is
false.
X Make sure the conditions for a correct classification of the per-
son on the front-passenger seat are met (Y page 50).
X If the PASSENGER AIR BAG OFF indicator lamp remains lit, the
front-passenger seat may not be used.
X Have the automatic front-passenger front airbag deactivation
system checked as soon as possible at a Mercedes-Benz Ser-
vice Centre. The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or does not stay
on.
The front-passenger
seat is:
R empty
R occupied with a rear-
ward-facing child
restraint system The automatic front-passenger front airbag deactivation system is
malfunctioning.
X Make sure there is nothing between the seat and the child
restraint system.
X Make sure that the entire base of the child restraint system rests
on the seat cushion of the front-passenger seat.
X Make sure that the seat cushion length is fully retracted.
X When installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight with the front-
passenger seat adjustment. This could result in the seat belt and the child restraint system being pulled too tightly.
X Check that the child restraint system is installed correctly.
X Make sure that no objects are applying additional weight to 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 rearward-facing child restraint system on the front-
passenger seat. It is recommended that you fit the child
restraint system to a suitable rear seat.
X Have the automatic front-passenger front airbag deactivation
system checked as soon as possible at a Mercedes-Benz Ser-
vice Centre. 54
Occupant safetySafety
Page 58 of 417
Deployment of belt tensioners and air-
bags
Important safety notes G
WARNING
After the airbag deploys, the airbag parts are
hot. There is a risk of injury.
Do not touch the airbag parts. Have a
deployed airbag replaced at a qualified spe-
cialist workshop as soon as possible. G
WARNING
Pyrotechnic seat belt tensioners that have
been deployed are no longer operational and
are unable to perform their intended protec-
tive function. This poses an increased risk of
injury or even fatal injury.
Therefore, have pyrotechnic belt tensioners
which have been triggered immediately
replaced at a qualified specialist workshop.
Mercedes-Benz recommends that you have
the vehicle towed to a qualified specialist
workshop after an accident. Take this into
account, particularly if a seat belt tensioner
was triggered or an airbag was deployed.
An electric motor is used by PRE-SAFE ®
to
trigger the tightening of the seat belt in haz-
ardous situations. This procedure is reversi-
ble.
If the belt tensioners are triggered or an air-
bag is deployed, you will hear a bang, and a
small amount of powder may also be
released. The 6restraint system warning
lamp lights up.
Only in rare cases will the bang affect your
hearing. In general, the powder released is
not hazardous to health but may cause short- term breathing difficulties to persons suffer-
ing from asthma or other pulmonary condi-
tions. Provided it is safe to do so, you should
leave the vehicle immediately or open the
window in order to prevent breathing difficul- ties. 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 triggers the seat
belt tensioners in the event of a head-on or
rear collision.
A seat belt tensioner can only be triggered if:
R the ignition is switched on
R the components of the restraint system are
operational. You can find further informa-
tion under: "Restraint system warning
lamp" (Y page 41)
R the belt tongue has engaged in the belt
buckle of the respective front seat
The seat belt tensioners in the rear compart-
ment are triggered independently of the lock
status of the seat belts.
If the restraint system control unit detects a
high severity accident, in certain head-on col- lisions, additional components of the
restraint system are deployed independently
of each other:
R front airbags and driver's kneebag
R windowbag, if the system determines that
deployment can offer additional protection
to that provided by the seat belt
On vehicles with the automatic front-
passenger front airbag deactivation system:
depending on the person in the front-
passenger seat, the front-passenger front air- bag is either disabled or enabled. The front-
passenger front airbag can only be deployed
in an accident if the PASSENGER AIR BAG ON
indicator lamp is lit. Observe the information
on the PASSENGER AIR BAG indicator lamps
(Y page 41).
Your vehicle has two-stage front airbags. In
the first deployment stage, the front airbag is Occupant safety
55Safety Z
Page 59 of 417
filled with propellant gas to reduce the risk of
injuries. The front airbag is fully deployed if
the second deployment stage is activated
within a few milliseconds.
The activation threshold for the seat belt ten-
sioners and airbags is determined based on
the evaluation of the vehicle's rate of decel-
eration or acceleration at various points in the vehicle. This process is pre-emptive in nature.The triggering/deployment process 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 airbag,
nor do they provide an indication of airbag
deployment.
The vehicle may be deformed significantly
without an airbag 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, an airbag 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, the applicable components of
the restraint system are activated independ-
ently of each other.
R Sidebags on the side on which an impact
occurs, independent from the seat belt ten-
sioner and seat belt usage
Vehicles with the automatic front-
passenger airbag deactivation system: the sidebag on the front-passenger side
deploys under the following conditions:
- an occupant is detected on the front-
passenger seat or
- the belt tongue is engaged in the belt
buckle of the front-passenger seat
R Windowbag on the side on which an impact
occurs, independent of seat belt usage and
regardless of whether the front-passenger
seat is occupied
R Seat belt tensioners, if the system deter-
mines that deployment can offer additional
protection for the vehicle occupants in this situation
i Not all airbags are deployed in an acci-
dent. The different airbag systems work
independently of each other.
How the airbag 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 PRE-SAFE
®
(anticipatory occupant
protection)
Introduction In certain hazardous situations, PRE-SAFE
®
takes pre-emptive measures to protect the
vehicle occupants.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats. There is a risk that the seats and/or the objects could be
damaged when PRE-SAFE ®
is activated.
Although your vehicle is equipped with PRE-
SAFE ®
, the possibility of injury in the event of
an accident cannot be ruled out. Always
adapt your driving style to suit the prevailing
road and weather conditions and maintain a 56
Occupant safetySafety
Page 60 of 417
safe distance from the vehicle in front. Drive
carefully.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely
R on vehicles with DISTRONIC PLUS: if adap-
tive Brake Assist intervenes powerfully
PRE-SAFE ®
takes the following measures
depending on the hazardous situation detec-
ted:
R the front seat belts are pre-tensioned.
R if the vehicle skids, the side windows and
the panorama sliding sunroof are closed.
R vehicles with the memory function: the
front-passenger seat is adjusted if it is in an
unfavourable position.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pre-tensioning. All settings made by
PRE-SAFE ®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
X Move the seat backrest or seat back
slightly when the vehicle is stationary.
Seat belt pre-tensioning is reduced and the locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. Infor-
mation about the convenience function can
be found under "Belt adjustment"
(Y page 45). Automatic measures after an acci-
dent
Immediately after an accident, the following
measures may be 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 and the fuel sup-
ply is cut off
R vehicles with the Mercedes-Benz emer-
gency call system: automatic emergency
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 twelve years old and
under 1.50 m in height is travelling 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 always pay attention to the instructions
and safety notes on the automatic front-
passenger front airbag deactivation system (Y page 49). Children in the vehicle
57Safety Z