MERCEDES-BENZ SLK-Class 2015 R172 Workshop Manual

The headbag on the front-passenger side
does not deploy under the following condi-
tions:
R OCS has detected that the front-passenger
seat is unoccupied.
R the front-passenger seat belt is not fas-
tened.
If the belt tongue is engaged in the belt
buckle, the headbag on the front-passenger
side deploys if an appropriate accident situa- tion occurs. In this case, it will deploy regard- less of whether the front-passenger seat is
occupied or not. 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 front-passenger head 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 you install a child restraint system on the
front-passenger seat, be sure to observe the
correct positioning of the child restraint sys-
tem. 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 OFF indicator lamp
0044 PASSENGER AIR BAG ON indicator lamp
PASSENGER AIR BAG OFF indicator lamp 0043
informs you whether the front-passenger
front air bag is deactivated.
X Turn the SmartKey to position 1or 2in the
ignition lock, or press the Start/Stop but-
ton once or twice on vehicles with KEY-
LESS-GO.
The system carries out a self-diagnosis.
The PASSENGER AIR BAG ON indicator lamp
is inoperative. It lights up briefly when the Occupant safety
49Safety Z

ignition is switched on and then goes out
again.
The PASSENGER AIR BAG OFF indicator lamp
must light up for approximately six seconds.
The PASSENGER AIR BAG OFF indicator lamp
then displays the status of the front-
passenger front air bag. If the status of the
front-passenger front air bag changes while
the vehicle is in motion, an air bag display
message may appear in the instrument clus-
ter (Y page 224). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG OFF indicator lamp. Be aware of the status of the front-passenger
front air bag both before and during the jour-ney.
If the PASSENGER AIR BAG OFF indicator
lamp:
R is lit, the front-passenger front air bag is
deactivated. They will then not be deployed in the event of an accident.
R does not light 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. G
WARNING
If the PASSENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is disabled. It will not be deployed in the event of
an accident and cannot perform its intended
protective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
When the front-passenger seat is occupied,
always ensure that:
R the classification of the person in the front-
passenger seat is correct and the front-
passenger front air bag is enabled or disa- bled in accordance with the person in the
front-passenger seat
R the front-passenger seat has been moved
back as far back as possible.
R the person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag is correct. G
WARNING
If you secure a child in a child restraint system on the front-passenger seat and the
PASSENGER AIR BAG OFF indicator lamp is
off, the front-passenger front air bag can
deploy in the event of an accident. The child
could be struck by the air bag. This poses an
increased risk of injury or even fatal injury.
Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit. G
WARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too close to the dashboard, 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 OFF indicator lamp is off
This poses an increased risk of injury or even fatal injury.
Move the front-passenger seat as far back as
possible. Always make sure that the shoulder belt strap is correctly routed from the vehicle
belt loop to the shoulder belt guide on the
child restraint system. The shoulder belt strap
must be routed forwards and downwards
from the vehicle belt loop. Always observe the child restraint system manufacturer's instal-
lation instructions. 50
Occupant safetySafety

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 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 OFF indicator lamp
can go out 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. Make sure that the condi-
tions for a correct classification are met. If the PASSENGER AIR BAG OFF indicator
lamp remains off, do not install a child
restraint system on the front-passenger
seat.
R the front-passenger seat is occupied by a
person of smaller stature (e.g. a teenager
or small adult), the PASSENGER AIR BAG
OFF indicator lamp lights up and remains lit
after the system self-test depending on the result of the classification or, alternatively,
goes out.
- if the PASSENGER AIR BAG OFF indicator
lamp is off, move the front-passenger
seat as far back as possible.
- 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 OFF indicator lamp goes out after the
system self-test. 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" (Y page 57).
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 the PASSENGER AIR BAG OFF indicator
lamp does not light up during the system self- test, then the system is malfunctioning. The
front-passenger front air bag might be trig-
gered unintentionally or might not be trig-
gered at all in the event of an accident with
high deceleration. This poses an increased
risk of injury or even fatal injury.
In this case the front-passenger seat may not be used. Do not install a child restraint system
on the front-passenger seat. Have the Occu-
pant Classification System (OCS) checked
and repaired immediately at a qualified spe-
cialist workshop. Occupant safety
51Safety Z

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-
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 indicator lamp displays the sta-
tus of the front-passenger front air bag
(Y page 49).
For more information about the OCS, see
"Problems with the Occupant Classification
System" (Y page 53). 52
Occupant safetySafety

Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Y
page 51).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 49).
X If the PASSENGER AIR BAG OFF indicator lamp remains lit, the
front-passenger seat may not be used.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or does not stay
on.
The front-passenger
seat is:
R unoccupied
R occupied 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 forwards-facing child restraint system must, as far as pos-
sible, be resting on the backrest of 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 with the front-
passenger seat adjustment. This could result in the seat belt and the child restraint system being pulled too tightly.
X Check the 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, do
not install a child restraint system on the front-passenger seat.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. Occupant safety
53Safety Z

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.
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 Emergency Tensioning Devices or air
bags are deployed, you will hear a bang and a small amount of powder may also be released. The
0075restraint system warning
lamp will light up.
Only in rare cases will the bang affect your
hearing. The powder released is generally not hazardous to health, it could however cause
short-term breathing difficulties in people
with asthma or other respiratory problems. In
order to prevent breathing difficulties, you
should leave the vehicle as soon as it is safe to
do so, or open the window.
Air bags and pyrotechnic seat belt tensioners
contain perchlorate material, which may
require special handling or environmental
protection measures. Check with your local
government’s disposal guidelines. California
residents, 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 triggers the belt
tensioners in the event of a frontal or rear
collision.
If the restraint system control unit detects a
high accident severity, additional compo-
nents of the restraint system are activated
independently of one another in certain fron- tal collision situations:
R Front air bags as well as driver's and front-
passenger kneebag
Depending on the person occupying the front-
passenger seat, the front-passenger air bag is activated or deactivated. The front-passenger front air bag can only be deployed in an acci-
dent if the PASSENGER AIR BAG OFF indica-
tor lamp is off. Observe the information on the 54
Occupant safetySafety

PASSENGER AIR BAG OFF indicator lamp
(Y page 41).
Your vehicle has two-stage front air bags.
During the first deployment stage, the front
air bag fills with propellant gas which reduces the risk of injury. The second stage is then
triggered within milliseconds, filling the front
air bag with the maximum amount of propel-
lant gas.
The deployment thresholds for the Emer-
gency Tensioning Devices and air bags are
calculated on the basis of the vehicle decel-
eration or acceleration occurring at various
points in the vehicle. This process is pre-emp-
tive in nature. The air bag must be deployed
on 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 distribution of the force during the impact
R collision angle
R deformation characteristics of the vehicle
R characteristics of the object with which the
vehicle has collided
Factors which can only be seen and measured after the collision has occurred do not play a
decisive role in the deployment of an airbag,
nor do they provide an indication of air bag
deployment.
The vehicle may be considerably deformed
without an air bag being deployed. This is the
case if only relatively easily deformable parts
have been hit and a high rate of deceleration
has not been reached. Conversely, an air bag may be deployed even though the vehicle suf-
fers only minor deformation. This is the case
if, for example, very rigid vehicle parts such as the longitudinal body members are hit in an
accident and the rate of deceleration is suffi-
cient. If the restraint system control unit detects a
side impact or an overturn situation, the rel-
evant restraint system components are acti-
vated independently of one another depend-
ing on the apparent type of accident. If addi-
tional protection for the vehicle occupants is determined in this situation, the belt tension-
ers are also triggered.
R Sidebag on the side on which the impact
occurs, independently of the belt tensioner
and of the use of the seat belt on the driv-
er's seat
The sidebag on the front-passenger side
deploys under the following conditions:
- the OCS system detects that the front-
passenger seat is occupied or
- the belt tongue has engaged in the belt
buckle of the front-passenger seat.
R Headbag on the side on which the impact
occurs, independently of the use of the seat
belt and independently of whether the
front-passenger seat is occupied
R Headbags on the driver's and front-
passenger sides in certain overturn situa-
tions if the system determines that they
can offer additional protection to that pro-
vided by the seat belt
i Not all air bags are deployed in an acci-
dent. The various air bag systems work
independently of each other.
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 Occupant safety
55Safety Z

NECK-PRO head restraints
Important safety notes G
WARNING
The function of the head restraint may be
impaired if you:
R attach objects such as coat hangers to the
head restraints, for example
R use head restraint covers
If you do so, the head restraints cannot fulfill
their intended protective function in the event of an accident. In addition, objects attached
to the head restraints could endanger other
vehicle occupants. There is an increased risk
of injury.
Do not attach any objects to the head
restraints and do not use head restraint cov-
ers.
Method of operation NECK-PRO head restraints reduce the likeli-
hood of head and chest injuries. The NECK-
PRO head restraints on the driver's and front-
passenger seats are moved forwards and
upwards in the event of a rear-end collision of
a certain severity. This provides better head
support.
If the NECK-PRO head restraints have been
triggered in an accident, you must reset the
NECK-PRO head restraints on the driver’s and
front-passenger seat (Y page 56). Other-
wise, the additional protection will not be
available in the event of another rear-end col- lision. You can recognize when NECK-PRO
head restraints have been triggered by the
fact that they have moved forwards and can
no longer be adjusted.
Mercedes-Benz recommends that you have
the NECK-PRO head restraints checked for
functionality at a qualified specialist work-
shop after a rear-end collision. Resetting triggered NECK-PRO head
restraints
Do not insert your finger between the uphols-
tery of the head restraint and the seat. Pay
particular attention while resetting the NECK- PRO head restraints.
X Tilt the top of the NECK-PRO head restraint
cushion forwards in the direction of
arrow 0043.
X Push the NECK-PRO head restraint cushion
down as far as it will go in the direction of
arrow 0044.
X Firmly push the NECK-PRO head restraint
cushion back in the direction of arrow 0087
until the cushion engages.
X Repeat this procedure for the second
NECK-PRO head restraint.
i Resetting the NECK-PRO head restraints
requires a lot of strength. If you have diffi-
culty resetting the NECK-PRO head
restraints, have this work carried out at a
qualified specialist workshop. PRE-SAFE
®
(anticipatory occupant
protection system)
Introduction PRE-SAFE
®
is only available in vehicles with
the Driving Assistance package.
AMG vehicles: PRE-SAFE®
is not available.
In certain hazardous situations, PRE-SAFE ®
takes pre-emptive measures to protect the
vehicle occupants. 56
Occupant safetySafety

Important safety notes
!
Make sure that there are no objects in the
footwell or behind the seats. There is a dan- ger that the seats and/or 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
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 the Driving Assistance
package: if BAS PLUS intervenes power-
fully or the radar sensor system detects an
imminent danger of collision in certain sit-
uations
PRE-SAFE ®
takes the following measures
depending on the hazardous situation detec-
ted:
R the seat belts are pre-tensioned.
R if the vehicle skids, the side windows are
closed so that only a small gap remains.
R vehicles with the memory function: the
front-passenger seat is adjusted if it is in an
unfavorable 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.
The 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 are implemented, depending on
the type and severity of the impact: R by activating the hazard warning lamps
R the emergency lighting is activated
R the vehicle doors are unlocked
R the front side windows are lowered
R in vehicles with a memory function: the
electrically adjustable steering wheel is
raised
R the engine is switched off
R vehicles with mbrace: automatic emer-
gency call Children in the vehicle
Important safety notes
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 49) Children in the vehicle
57Safety Z

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 park
position Por shift manual transmission into
neutral.
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.
Observe the safety notes on the seat belt
(Y page 42) and the notes on correct use of
seat belts (Y page 44). A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg) or until they reach a height
where a lap/shoulder belt can be fastened
properly without a booster seat. Special seat belt retractor
G
WARNING
If the seat belt is released while driving, the
child restraint system will no longer be
secured properly. The special seat belt retrac- tor is disabled and the inertia real draws in a
portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reactivate
the special seat belt retractor and secure the
child restraint system properly.
The seat belt on the front passenger side is
equipped with a special seat belt retractor.
When activated, the special seat belt retrac-
tor ensures that the seat belt cannot slacken once the child seat is secured.
Installing a child restraint system:
X Make sure you observe the child restraint
system manufacturer's installation instruc- tions.
X Pull the seat belt smoothly out of the belt
loop.
X Engage seat belt tongue in belt buckle.
Activating the special seat belt retractor:
X Pull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat
belt retractor is enabled.
X Push the child restraint system down so
that the seat belt is tight and does not
loosen. 58
Children in the vehicleSafety