
This poses an increased risk of injury or even
fatal injury.
Never modify parts of the restraint system.
Never tamper with the wiring, the electronic
components or their software.
If it is necessary to modify an air bag system to
accommodate a person with disabilities, con-
tact an authorized Mercedes-Benz Center for
details. USA only: for further information con-
tact our Customer Assistance Center at
1-800-FOR-MERCedes (1 ‑ 800 ‑ 367 ‑ 6372).
Restraint system warning lamp The functions of the restraint system are
checked after the ignition is switched on and at
regular intervals while the engine is running.
Therefore, malfunctions can be detected in
good time.
The u restraint system warning lamp in the
instrument cluster lights up when the ignition is
switched on. It goes out no later than a few sec-
onds after the vehicle is started. The compo-
nents of the restraint system are in operational
readiness.
A malfunction has occurred if the u restraint
system warning lamp: R
does not light up after the ignition is switched
on R
does not go out after a few seconds with the
engine running R
lights up again while the engine is running
All vehicles, except hybrid vehicles:
G WARNING
If restraint system is malfunctioning, restraint
system components may be triggered unin-
tentionally or might not be triggered at all in
the event of an accident with a high rate of
vehicle deceleration. This can affect the Emer-
gency Tensioning Device or air bag, for exam-
ple. This poses an increased risk of injury or
even fatal injury.
Have the restraint system checked and
repaired in a qualified specialist workshop as
soon as possible.
Hybrid vehicles: G DANGER
If the restraint system is malfunctioning, indi-
vidual restraint system components may be
triggered unintentionally or might not be trig-
gered at all in the event of an accident with a
high rate of vehicle deceleration. This could
affect Emergency Tensioning Devices or air
bags, for example. The vehicle's high-voltage
electrical system may also not be deactivated
as intended in the event of an accident. You
could suffer an electric shock if you touch the
damaged components of the vehicle's high-
voltage electrical system. This poses an
increased risk of injury or even fatal injury.
Have the restraint system checked and
repaired immediately at a qualified specialist
workshop. Immediately switch off the ignition
and remove the SmartKey from the ignition
lock after an accident.
PASSENGER AIR BAG indicator lamp
PASSENGER AIR BAG ON indicator lamp C and
PASSENGER AIR BAG OFF indicator lamp D are
part of the Occupant Classification System
(OCS).
The indicator lamps display the status of the
front-passenger front air bag. R
PASSENGER 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. R
PASSENGER AIR BAG OFF lights up: the front-
passenger front air bag is deactivated. It will
then not be deployed in the event of an acci-
dent.Occupant safety 45
Safety Z

Depending on the person in the front-passenger
seat, the front-passenger front air bag must
either be deactivated or enabled; see the fol-
lowing points. You must make sure of this both
before and during a journey. R
Children in a child restraint system:
whether the front-passenger front air bag is
enabled or deactivated depends on the instal-
led child restraint system, and the age and
size of the child. Therefore, be sure to observe
the notes on the "Occupant Classification
System (OCS)" ( Y
page 52) and on "Chil-
dren in the vehicle" ( Y
page 60). There you
will also find instructions on rearward and
forward-facing child restraint systems on the
front-passenger seat. R
All other persons: depending on the classi-
fication of the person in the front-passenger
seat, the front-passenger front air bag is ena-
bled or deactivated ( Y
page 52). Be sure to
observe the notes on "Seat
belts“ ( Y
page 46) and "Air bags"
( Y
page 49). There you can also find infor-
mation on the correct seat position.
Seat belts
Introduction Seat belts are the most effective means of
restricting the movement of vehicle occupants
in the event of an accident or the vehicle rolling
over. This reduces the risk of vehicle occupants
coming into contact with parts of the vehicle
interior or being ejected from the vehicle. Fur-
thermore, the seat belt helps to keep the vehicle
occupant in the best position in relation to the
air bag.
The seat belt system comprises: R
Seat belts R
Emergency Tensioning Devices for the front
seat belts and the outer seat belts in the rear R
Seat belt force limiters
If the seat belt is pulled out of the belt outlet
quickly or with a jerky movement, the belt
retractor locks. The belt strap cannot be extrac-
ted any further.
The Emergency Tensioning Device tightens the
seat belt in an accident, pulling the belt close
against the body. However it does not pull the
vehicle occupant back in the direction of the
backrest. The Emergency Tensioning Device does not cor-
rect an incorrect seat position or the routing of
an incorrectly fastened seat belt.
When triggered, a seat belt force limiter helps to
reduce the force exerted by the seat belt on the
vehicle occupant.
The seat belt force limiters for the front s eats are
s ynchronized with the front air bags, which
absorb part of the deceleration force. This can
reduce the force exerted on the vehicle occu-
pants during an accident.
! If the front-passenger seat is unoccupied,
do not insert the belt tongue into the buckle of
the front-passenger seat. This may otherwise
lead to the triggering of the Emergency Ten-
sioning Device in the event of an accident,
which will then need to be replaced.
Important safety notes The use of seat belts and child restraint systems
is required by law in: R
all 50 states R
the U.S. territories R
the District of Columbia R
all Canadian provinces
Even where this is not required by law, all vehicle
occupants should correctly fasten their seat
belts before starting the journey.
G WARNING
If the seat belt is incorrectly fastened, it can-
not protect as intended. Furthermore, an
incorrectly fastened seat belt can cause addi-
tional injury, for example, in an accident, dur-
ing braking or when abruptly changing direc-
tion. This poses an increased risk of injury or
even fatal injury.
Make sure that all vehicle occupants are
seated properly with a correctly fastened seat
belt.
G WARNING
The seat belt does not offer the intended level
of protection if you have not moved the back-
rest to an almost vertical position. When brak-
ing or in the event of an accident, you could
slide underneath the seat belt and sustain
abdomen or neck injuries, for example. This46
Occupant safety
Safety

Occupant Classification System
(OCS)
Introduction The Occupant Classification System (OCS) cat-
egorizes 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 deactivate: R
the side impact air bag R
the window curtain air bag R
the Emergency Tensioning Devices
In the following situation, the side impact air bag
and the Emergency Tensioning Device are deac-
tivated: R
OCS has not categorized the person on the
front-passenger seat as an adult or a person
of corresponding stature and R
the seat belt tongue of the seat belt is not
inserted into the front-passenger seat belt
buckle
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 possible
If the front passenger does not observe these
conditions, OCS may produce a false classifica-
tion, 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
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 backrest
and the head restraint position accordingly.
Only then can OCS be guaranteed to function
correctly. Always observe the child restraint sys-
tem manufacturer's installation instructions.
Occupant Classification System opera-
tion (OCS)
C
PASSENGER AIR BAG ON indicator lamp D
PASSENGER AIR BAG OFF indicator lamp
The indicator lamps indicate whether the front-
passenger front air bag is activated or deactiva-
ted. X
Press the start/stop button once or twice, or
turn the SmartKey to position 1 or 2 in the
ignition lock.
The system carries out a self-diagnosis test.
The PASSENGER AIR BAG OFF and PASSENGER
AIR BAG ON indicator lamps must light up simul-
taneously for about six seconds.
The indicator lamps then display the status of
the front-passenger front air bag: R
PASSENGER AIRBAG ON lights up: the front-
passenger front airbag is enabled. If, in the
case of an accident, all deployment criteria
are met, the front-passenger front air bag is
deployed. R
PASSENGER AIRBAG 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 whilst the vehicle is in motion, an air
bag display message may appear in the instru-
ment cluster ( Y
page 290). Always observe the
PASSENGER AIR BAG ON and PASSENGER AIR
BAG OFF indicator lamps when the front-
passenger seat is occupied. Make sure that the
status of the front-passenger front air bag is
correct before and during a journey.52
Occupant safety
Safety

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 trig-
ger the tightening of the seat belt in hazardous
situations. This procedure is reversible.
If Emergency Tensioning Devices are triggered
or air bags are deployed, you will hear a bang,
and a small amount of powder may also be
released. The u restraint system warning
lamp lights up.
Only in rare cases will the bang affect your hear-
ing. The powder that is released generally does
not constitute a health hazard, but it may cause
short-term breathing difficulties in people with
asthma or other respiratory problems. Provided
it is safe to do so, you should leave the vehicle
immediately or open the window in order to pre-
vent breathing difficulties.
Air bags and pyrotechnic Emergency Tensioning
Devices (ETDs) contain perchlorate material,
which may require special handling and regard
for the environment. National guidelines 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 important physi-
cal data relating to vehicle deceleration or accel-
eration, such as: R
duration R
direction R
intensity
Based on the evaluation of this data, the
restraint system control unit triggers the Emer-
gency Tensioning Devices during a frontal or
rear collision.
An Emergency Tensioning Device can only be
triggered, if: R
the ignition is switched on R
the components of the restraint system are
operational. You can find further information
under: "Restraint system warning lamp"
( Y
page 45) R
the belt tongue is engaged in the buckle on
the respective front-passenger seat
The Emergency Tensioning Devices in the rear
compartment are triggered independently of the
lock status of the seat belts.
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 and driver's knee bag 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 indicator lamp is lit.
Observe the information on the PASSENGER AIR
BAG indicator lamps ( Y
page 45).
Your vehicle has two-stage front air bags. During
the first d eployment stage, the front air bag is
fi
lled with propellant gas to reduce the risk of
injuries. The front air bag is fully deployed with
the maximum amount of propellant gas if a sec-
ond deployment threshold is reached within a
few milliseconds.
The activation threshold of the Emergency Ten-
sioning Devices and the air bag are determined
by evaluating the rate of vehicle deceleration or
acceleration which occurs at various points inOccupant safety 57
Safety Z

PRE-SAFE ®
takes the following measures
depending on the hazardous situation detected: R
the front seat belts are pre-tensioned. R
if the vehicle skids, the side windows and the
sliding sunroof are closed. R
vehicles with the memory function: the front-
passenger seat is adjusted if it is in an unfav-
orable position. R
vehicles with a multicontour seat: the air pres-
sure in the side bolsters of the seat backrest
is increased.
If the hazardous situation passes without result-
ing in an accident, PRE-SAFE ®
slackens the belt
pre-tensioning. On vehicles with multicontour
seats, the air pressure in the side bolsters is
reduced again. 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. Informa-
tion about the convenience function can be
found under "Belt adjustment" ( Y
page 48).
PRE-SAFE ®
PLUS (anticipatory occu-
pant protection system PLUS)
Introduction PRE-SAFE ®
PLUS is only available in vehicles
with the Driving Assistance package.
Using the radar sensor system, PRE-SAFE ®
PLUS is able to detect that a head-on or rear-end
collision is imminent. In certain hazardous sit-
uations, PRE-SAFE ®
PLUS takes pre-emptive
measures to protect the vehicle occupants.
Important safety notes
The intervention of PRE-SAFE ®
PLUS cannot
prevent an imminent collision.
The driver is not warned about the intervention
of PRE-SAFE ®
PLUS.
PRE-SAFE ®
PLUS does not intervene if the vehi-
cle is backing up.
When driving, or when parking or exiting a park-
ing space with assistance from Active Parking Assist, PRE-SAFE ®
PLUS will not apply the
brakes.
Function PRE-SAFE ®
PLUS intervenes in certain situa-
tions if the radar sensor system detects an
imminent head-on or rear-end collision.
PRE-SAFE ®
PLUS takes the following measures
depending on the hazardous situation detected: R
if the radar sensor system detects that a
head-on collision is imminent, the seat belts
are pre-tensioned. R
if the radar sensor system detects that a rear-
end collision is imminent: -
the brake pressure is increased if the driver
applies the brakes when the vehicle is sta-
tionary. -
the seat belts are pre-tensioned.
The PRE-SAFE ®
PLUS braking application is can-
celed: R
if the accelerator pedal is depressed when a
gear is engaged R
if the risk of a collision passes or is no longer
detected R
if DISTRONIC PLUS indicates an intention to
pull away
If the hazardous situation passes without result-
ing in an accident, the original settings are
restored.
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
vehicles with a memory function: the electri-
cally adjustable steering wheel is raised R
the engine is switched off and the fuel supply
is cut offOccupant safety 59
Safety Z

R
vehicles with mbrace: automatic emergency
call R
vehicles with the hybrid drive system: the
hybrid system and the high-voltage electrical
system are deactivated
Children in the vehicle
Important safety notes Accident statistics show that children secured
in the rear seats are safer than children 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 protected there.
If a child younger than twelve years old 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 vehicles.
The child restraint system must be appropri-
ate 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 classification system
(OCS)" ( Y
page 52)
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 child
restraint 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 sitting
properly. Particular attention must be paid to
children.
Observe the safety notes on the seat belt
( Y
page 46) and the notes on correct use of seat
belts ( Y
page 47).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg) until they reach a height where a
three-point seat belt can be properly fastened
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.
All seat belts in the vehicle, except the driver's
seat belt, are equipped with a special seat belt60
Children in the vehicle
Safety

The securing systems of child restraint systems
are: R
the seat belt system R
the LATCH-type (ISOFIX) securing rings R
the Top Tether anchorages
If it is absolutely necessary to carry a child on
the front-passenger seat, be sure to observe the
information on the "Occupant Classification
System (OCS)" ( Y
page 52). There you will also
find information on deactivating the front-
passenger front air bag.
All child restraint systems must meet the fol-
lowing standards: R
U.S. Federal Motor Vehicle Safety Standards
213 and 225 R
Canadian Motor Vehicle Safety Standards
213 and 210.2
Confirmation that the child restraint system cor-
responds to the standards can be found on an
instruction label on the child restraint system.
This confirmation can also be found in the instal-
lation instructions that are included with the
child restraint system.
Observe the warning labels in the vehicle inte-
rior and on the child restraint system.
LATCH-type (ISOFIX) child seat secur-
ing system
G WARNING
LATCH-type (ISOFIX) child restraint systems
do not offer sufficient protective effect for
children whose weight is greater than 48 lbs
(22 kg) who are secured using the safety belt
integrated in the child restraint system. In the
event of an accident, a child might not be
restrained correctly. This poses an increased
risk of injury or even fatal injury.
If the child weighs more than 48 lbs (22 kg),
only use LATCH-type (ISOFIX) child restraint
systems with which the child is also secured
with the vehicle seat belt. Also secure the
child restraint system with the Top Tether
belt, if available.
Always comply with the manufacturer's instal-
lation and operating instructions for the child
restraint system used. Before every trip, make sure that the LATCH-
type (ISOFIX) child restraint system is engaged
correctly in both LATCH-type (ISOFIX) securing
rings
! When installing the child restraint system,
make sure that the seat belt for the middle
seat does not get trapped. The seat belt could
otherwise be damaged.
LATCH-type (ISOFIX) securing rings X
Install the LATCH-type (ISOFIX) child restraint
system on both LATCH-type (ISOFIX) securing
rings C .
ISOFIX is a standardized securing system for
specially designed child restraint systems on
the rear seats. LATCH-type (ISOFIX) securing
rings for two LATCH-type (ISOFIX) child restraint
systems are installed on the left and right of the
rear seats.
Non-LATCH-type (ISOFIX) child seats may also
be used and can be installed using the vehicle's
seat belt system. Install the child seat according
to the manufacturer's instructions.
Top Tether
Introduction Top Tether provides an additional connection
between the child restraint system secured with
a LATCH-type (ISOFIX) system and the vehicle.
This helps reduce the risk of injury even further.
If the child restraint system is equipped with a
Top Tether belt, this should always be used.
Important safety notes
G WARNING
If the rear seat backrests are not locked, they
could fold forwards in the event of an acci-62
Children in the vehicle
Safety

dent, heavy braking or sudden changes of
direction. As a result, child restraint systems
cannot perform their intended protective
function. Rear seat backrests that are not
locked can also cause additional injuries, e.g.
in the event of an accident. This poses an
increased risk of injury or even fatal injury.
Always lock rear seat backrests after instal-
ling a Top Tether belt. Adjust the rear seat
backrests so that they are in an upright posi-
tion.
Make sure that the backrest in the rear com-
partment engages fully. To do so, pull firmly on
the seat backrest.
Top Tether anchorages
Top Tether anchorage points