
seconds when the engine is started.
Depending on occupant weight sensor
readings from the seat, it will then remain
illuminated
or
go out. If the 4 PASSENGER
AIR BAG OFF indicator lamp is illuminated, the
front-passenger front air bag and the front-
passenger knee bag are deactivated. If the
4 PASSENGER AIR BAG OFF indicator
lamp is not illuminated, the front-passenger
front air bag and the front-passenger knee
bag are activated.
When the OCS senses that the front-
passenger seat occupant is classified as an
adult or someone larger than a small
individual, the 4 PASSENGER AIR BAG
OFF indicator lamp will illuminate for
approximately six seconds when the engine is
started and then go out. This indicates that
the front-passenger front air bag and the
front-passenger knee bag are activated.
If the 4 PASSENGER AIR BAG OFF
indicator lamp is illuminated, the front-
passenger front air bag and the front-
passenger knee bag are deactivated and are
not deployed.
If the 4 PASSENGER AIR BAG OFF
indicator lamp is not illuminated, the front-
passenger front air bag and the front-
passenger knee bag are activated and are
deployed:
R in certain front impacts
R independently of the side impact air bag
and head bag
R if the impact has exceeded a
predetermined threshold value for
deployment
If the front-passenger front air bag is
deployed, the rate of inflation will be
influenced by:
R the rate of vehicle deceleration as assessed
by the air bag control unit
R the front passenger's weight category as
determined by the OCS G
WARNING
Children under 12 years must be secured
correctly in
a suitable infant or child restraint
system or booster seat suitable for the size
and weight of the child.
The infant or child restraint must be properly
secured with the vehicle's seat belt fully in
accordance with the child seat
manufacturer's instructions.
Occupants, in particular children, must sit as
upright as possible, fasten the seat belt
correctly and use a suitable infant restraint
system, child restraint system or booster seat
suitable for the size and weight of the child.
Children can be seriously or even fatally
injured by an air bag deploying.
Observe the following information:
R Your vehicle is equipped with air bag
technology designed to deactivate the
front-passenger front air bag and the front-
passenger knee bag in your vehicle when
the system senses the weight of a typical
12-month-old child or less along with the
weight of a standard appropriate child
restraint on the front-passenger seat.
R A child in a rear-facing child restraint
system on the front-passenger seat will be
seriously injured or even killed if the front-
passenger front air bag inflates in a collision
despite the air bag technology installed in
your vehicle, which could occur under some
circumstances.
R If you must install a rearward-facing child
restraint on the front-passenger seat, make
sure the 4 PASSENGER AIR BAG OFF
indicator lamp is illuminated, indicating
that the front-passenger front air bag and
front-passenger knee bag are deactivated.
If the 4 PASSENGER AIR BAG OFF
indicator lamp does not light up or goes out
when a rearward-facing child restraint
system is installed, please check
installation. Periodically check the 4
PASSENGER AIR BAG OFF indicator lamp
while driving to make sure the 444
Occupant safety
Safety

PASSENGER AIR BAG OFF indicator lamp is
illuminated. If the 4 PASSENGER AIR
BAG OFF indicator lamp goes out or
remains out do not carry a child on the
front-passenger seat.
R A child in a rearward-facing child restraint
system on the front-passenger seat will be
seriously injured or even killed if the front-
passenger air bag is deployed.
R When securing a child in a child restraint
system on the front-passenger seat, you
must:
-move the front-passenger seat as far
back as possible
- use a child restraint system that is
suitable for the age, size and weight of
the child
- observe the manufacturer's installation
instructions in
order to install and secure
the child restraint system correctly.
R For children larger than the typical 12-
month-old child, the front-passenger front
air bag may or may not be activated. G
WARNING
If the red
6 SRS warning lamp in the
instrument cluster
and the 4 PASSENGER
AIR BAG OFF indicator lamp light up
simultaneously, the OCS is malfunctioning.
The front-passenger front air bag and the
front-passenger knee bag will be deactivated
in this case. Have the system checked as soon
as possible by qualified technicians. Consult
an authorized Mercedes-Benz Center.
Only have the seat repaired at an authorized
Mercedes-Benz Center.
In order to ensure correct operation of the air
bag system and OCS:
R sit with the seat belt fastened correctly and
in a position that is as upright as possible
with your back against the backrest.
R while seated, an occupant should not
position themselves in such a way as to
cause their weight to be lifted from the seat
cushion as this may result in OCS being unable to correctly assess the occupant's
weight category.
R read and observe all warnings in this
section. If
the key has been removed from the ignition
lock or is in position 0, the ^a
indicator lamp : does not light up.
The ^_ indicator lamp ; is
inoperative. It lights up briefly when the
ignition is switched on and then goes out
again.
The Occupant Classification System (OCS)
categorizes the occupant on the front-
passenger seat using a weight sensor. The
front-passenger front air bag and the front-
passenger knee bag are deactivated
automatically for certain weight categories.
The ^a indicator lamp : shows you
the current
status. If the ^a indicator
lamp : lights up, the front-passenger air bag
and the front-passenger knee bag are
disabled.
The system does not deactivate:
R the side impact air bag
R the front-passenger head bag
R the Emergency Tensioning Devices
To be classified correctly, the front passenger
must sit:
R with the seat belt fastened correctly
R in a position that is as upright as possible
with their back against the seat backrest
R with their feet on the floor Occupant safety
45
Safety Z

The OCS weight sensor reading is affected if
the occupant's weight is transferred, e.g. by
leaning on the armrest.
If
the
front-passenger seat, the seat cover or
the seat cushion are damaged, have the
necessary repair work carried out at a
qualified specialist workshop.
Mercedes-Benz recommends that you only
use seat accessories which have been
approved by Mercedes-Benz.
Both the driver and the front passenger
should observe the ^a indicator
lamp : to determine whether or not the front
passenger is positioned correctly.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
will also deploy.
The OCS may have detected that the seat:
R is empty or occupied by the weight of a
typical child up to twelve months old,
seated in a child restraint system
R is occupied by a small individual, such as a
young teenager or a small adult
R is occupied by a child in a child restraint
system whose weight is greater than that
of a typical twelve month old child.
These are examples of when the OCS
deactivates the front-passenger front air bag
and front-passenger knee bag. Deactivation
takes place although the collision fulfills the
criteria for deploying the driver's air bag.
System self-test G
WARNING
If the 4 PASSENGER AIR BAG OFF
indicator lamp
does not illuminate, the system
is not functioning. Consult an authorized
Mercedes-Benz Center before seating a child
on the front-passenger seat. G
WARNING
Never place anything between seat cushion
and child
seat (e.g. a pillow), since it reduces
the effectiveness of the OCS. The underside and rear side child restraint system must be
placed entirely on the seat cushion and the
backrest of the front-passenger seat
backrest.
If necessary, adjust the tilt of the passenger
seat backrest.
An
incorrectly
mounted child seat could cause
injuries to the child in case of an accident,
instead of increasing protection for the child.
Follow the manufacturer's instructions for
installation of child restraint systems.
The ^a indicator lamp lights up:
R if you turn the SmartKey in the ignition lock
to position 1 or 2
R if you press the KEYLESS-GO Start/Stop
button once or twice on vehicles with
KEYLESS-GO
R if an adult is seated properly on the front-
passenger seat and the OCS classifies the
occupant as an adult
The ^a indicator lamp goes out after
approximately 6 seconds.
If the seat is not occupied and the OCS
detects that the front-passenger seat is
empty, the ^a indicator lamp will
continue to light up. The ^a front-
passenger front air bag warning lamp then
stays lit continuously.
For more information about the OCS, see
"Problems with the Occupant Classification
System" ( Y page 47).46
Occupant safety
Safety

Problems with the occupant classification system
G
WARNING
If the 4 PASSENGER AIR BAG OFF indicator lamp illuminates and remains illuminated when
the weight
of a typical adult or an individual that is the size of a typical adult has been detected
on the front-passenger seat, do not allow any occupant to use the front-passenger seat until the
system has been repaired. G
WARNING
If the 4
PASSENGER AIR BAG OFF indicator lamp does not illuminate or remains out with the
weight of a typical 12-month-old child in a standard child restraint or less, or is unoccupied, on
the front-passenger seat, do not transport a child on the front-passenger seat until the system
has been repaired. Problem Possible causes/consequences and
M SolutionsThe ^a
indicator
lamp
lights up
and stays on.
The person on the
front-passenger seat:
R has the weight of a
typical adult
R has been determined
by the system not to
be a child The OCS is malfunctioning.
X
Have the OCS checked as soon as possible at a qualified
specialist workshop.
X Observe the additional messages in the multifunction display
(Y page 234). Problem Possible causes/consequences and
M SolutionsThe ^a
indicator
lamp
does not
light up and/or does
not stay on.
The front-passenger
seat is:
R unoccupied
R occupied with a
weight up to that of a
typical twelve-
month-old child in a
standard child
restraint system The OCS is malfunctioning.
X
Make sure there is nothing between the seat cushion and the
child seat.
X Check the installation of the child restraint system.
X Make sure that no objects are applying additional weight onto
the seat.
X If the ^a indicator lamp remains off, have the OCS
checked as
soon as possible at a qualified specialist workshop.
Do not transport a child on the front-passenger seat as long as
the OCS is not functioning.
X Observe the additional messages in the multifunction display
(Y page 234). Occupant safety
47
Safety Z

PRE-SAFE
®
(preventative occupant
protection) G
WARNING
Make sure that nobody can become trapped
as you adjust the seat. G
WARNING
The PRE-SAFE
®
system
reduces the impact of
an accident on vehicle occupants, as long as
their seat belts have been fastened correctly.
Although your vehicle is equipped with a PRE-
SAFE ®
system, the possibility of injury in the
event of an accident cannot be ruled out. You
should therefore always drive carefully and
adapt your driving style to the prevailing road,
weather and traffic conditions.
! Make sure that there are no objects in the
footwell or behind the seats when resetting
the seats. There is a risk that the seats
and/or the objects could be damaged.
PRE-SAFE ®
takes preemptive measures to
protect occupants in certain hazardous
situations.
PRE-SAFE ®
intervenes:
R if BAS intervenes, e.g. in emergency
braking situations
R when BAS PLUS intervenes powerfully on
vehicles with DISTRONIC PLUS.
R when the radar sensor system detects an
imminent danger of collision in certain
situations on vehicles with DISTRONIC
PLUS.
R in critical driving situations, e.g. when
physical limits are exceeded and the
vehicle understeers or oversteers severely
PRE-SAFE ®
takes the following measures
depending on the hazardous situation
detected:
R the seat belts are pre-tensioned.
R the front-passenger seat is adjusted if it is
in an unfavorable position.
R vehicles with a multicontour seat or active
multicontour seat: the air pressure in the side bolsters of the seat cushion and
backrest is increased.
R if the vehicle skids, the side windows are
closed almost completely.
If the hazardous situation passes without
resulting in
an accident, PRE-SAFE ®
slackens
the belt pretensioning. All settings made by
PRE-SAFE ®
can then be reversed.
If the seat belts are not released:
X Move the backrest or seat back slightly, but
only when the vehicle is stationary.
The belt pretensioning is reduced and the
locking mechanism is released.
More information about seat belt adjustment,
a convenience function integrated into PRE-
SAFE (
Y page 52). NECK-PRO head restraints
Introduction G
WARNING
Do
not secure any objects (e.g. coat hangers)
on the
NECK-PRO head restraints. Otherwise,
the NECK-PRO head restraints may not
function properly, or in the event of a rear-end
collision may not be able offer the level of
protection they are designed to provide. G
WARNING
Seat or head restraint covers can cause a
malfunction when the NECK-PRO head
restraints are activated or when the side
impact air bags are deployed, or they can
prevent this
completely. The NECK-PRO head
restraints or side impact air bags can
therefore not provide the intended protection.
Do not use any seat or head restraint covers. G
WARNING
For your protection, drive only with properly
positioned head restraints.
Adjust the
head restraint so that it is as close
to the head as possible and the center of the
head restraint supports the back of the head 48
Occupant safety
Safety

X
Engage belt tongue ; in buckle =.
Seat-belt adjustment: if necessary, the
driver's and front-passenger seat belts
automatically adjust to the upper body
(Y page 52).
X If necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
The seat belt on the front-passenger side is
equipped with
al special seat belt retractor to
secure a child restraint system properly to the
front-passenger seat. Further information on
the "special seat belt retractor"
(Y page 56).
For more information about releasing the seat
belt with release button ?, see "Releasing
seat belts" ( Y page 52).
Seat belt adjustment The seat-belt adjustment function adjusts the
driver's and front-passenger seat belt to the
upper body of the occupants.
The belt strap is tightened slightly when:
R
you engage the belt tongue in the belt
buckle and you then turn the SmartKey to
position 2 in the ignition lock.
R the SmartKey
is in position 2 in the ignition
lock and you then engage the belt tongue
in the buckle.
The seat-belt adjustment will apply a
retraction force if any slack is detected
between the occupant and the seat belt. Do
not hold on to the seat belt tightly while it is
adjusting. You can switch the seat-belt
adjustment on and off in the on-board
computer (Y page 219).
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function.
Further information on PRE-SAFE ®
(Pre-
Crash Safety System) ( Y page 48).
Releasing seat belts !
Make sure
that the seat belt is fully rolled
up. Otherwise, the seat belt or belt tongue will be trapped in the door or in the seat
mechanism. This could damage the door,
the door trim panel and the seat belt.
Damaged seat belts can no longer fulfill
their protective function and must be
replaced. Visit a qualified specialist
workshop.
X
Press release button ? on
belt buckle =.
X Guide belt tongue ; back to seat belt
guide :.
Belt warning for the driver and front
passenger Regardless of whether the driver's and front-
passenger seat belts have already been
fastened, the ü seat belt warning lamp
lights
up
for six seconds each time the engine
is started. It then goes out if the driver and
the front passenger have fastened their seat
belts.
If the driver's seat belt is not fastened when
the engine is started, an additional warning
tone will sound. The warning tone goes out
after approximately six seconds or once the
driver's seat belt is fastened. 52
Occupant safety
Safety

If after six seconds the driver or front
passenger have not fastened their seat belts
and the doors are closed, the
ü seat belt
warning lamp lights up:
R until the driver's or front passenger's seat
belt is fastened
R if a vehicle speed of 15 mph (25 km/h
) is
exceeded, a warning tone also sounds with
increasing intensity for a maximum of
60 seconds or until the driver or front
passenger have fastened their seat belts.
If the driver/front passenger unfasten their
seat belt while the vehicle is in motion, the
ü seat belt warning lamp lights up and a
warning tone sounds again.
The warning tone ceases even if the driver or
front passenger have still not fastened their
seat belt after 60 seconds. The ü seat belt
warning lamp stops flashing but remains
illuminated.
After the vehicle comes to a standstill, the
warning tone is reactivated and the ü seat
belt warning lamp flashes again if the vehicle
speed again exceeds 15 mph (25 km/h).
The ü seat belt warning lamp only goes
out if:
R both the driver and the front passenger
have fastened their seat belts.
or
R the vehicle is stationary and a door is open.
i For more information on the ü seat
belt warning lamp, see "Warning and
indicator lamps in the instrument cluster,
seat belt" ( Y page 256).
Emergency Tensioning Devices, belt
force limiters G
WARNING
Pyrotechnic ETDs that were activated must be
replaced.
For your safety, when disposing of the
pyrotechnic ETDs always follow our safety
instructions. These are available at any
authorized Mercedes-Benz Center. !
If the front-passenger seat is not
occupied, do not engage the seat belt
tongue in the buckle on the front-
passenger seat.
Otherwise, the Emergency
Tensioning Device could be triggered in the
event of an accident.
The seat belts are equipped with Emergency
Tensioning Devices and belt force limiters.
The ETDs tighten the seat belts in an accident,
pulling them close against the body.
The ETDs do not correct incorrect seat
positions or incorrectly fastened seat belts.
The ETDs do not pull vehicle occupants back
towards the backrest.
When triggered, seat belt force limiters help
to reduce the peak force exerted by the seat
belt on the vehicle occupant.
The seat belt force limiters are synchronized
with the front air bags, which take on a part
of the deceleration force. Thus, the force
exerted on the occupant is distributed over a
greater area.
The ETDs can only be activated when:
R the ignition is switched on.
R the restraint systems are operational; see
"SRS warning lamp" ( Y page 37).
R the belt tongue is engaged in the buckle on
each of the three-point seat belts.
The ETDs are triggered depending on the type
and severity of an accident:
R if, in the event of a head-on or rear-end
collision, the vehicle decelerates or
accelerates rapidly in a longitudinal
direction during the initial stages of the
impact
R if, in the event of a side impact, on the side
opposite the impact the vehicle
decelerates or accelerates rapidly in a
lateral direction
R if, in certain situations where the vehicle
overturns, the system determines that it
can provide additional protection
If the ETDs are deployed, you will hear a bang,
and a small amount of powder may also be Occupant safety
53
Safety Z

released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard. The
6 SRS warning lamp
lights up. Child restraint systems
Important safety notes
G
WARNING
Children 12 years old and under must be
seated and
properly secured in an appropriate
infant restraint, toddler restraint, or booster
seat recommended for the size and weight of
the child.
The infant or child restraint system must be
correctly secured using the vehicle's seat belt
in complete accordance with the child seat
manufacturer's instructions.
Occupants, in particular children, must sit as
upright as possible, fasten the seat belt
correctly and use a suitable infant restraint
system, child restraint system or booster seat
suitable for the size and weight of the child.
Children can be seriously or even fatally
injured by an air bag deploying. Observe the
following information:
R Your vehicle is equipped with air bag
technology designed to deactivate the
front-passenger front air bag in your vehicle
when the system senses the weight of a
typical 12-month-old child or less along
with the weight of a standard appropriate
child restraint on the passenger seat.
R A child in a rearward-facing child restraint
system on the front-passenger seat could
be seriously injured or even killed if the
front-passenger air bag inflates in a
collision despite the air bag technology
installed in your vehicle, which could occur
under some circumstances.
R If you install a rearward-facing child
restraint on the front-passenger seat, make
sure that the 4 PASSENGER AIR BAG
OFF indicator lamp is illuminated, indicating that the front-passenger front air
bag is deactivated. Should the
4
PASSENGER AIR BAG OFF indicator lamp
not illuminate or go out while a rearward-
facing child restraint system is installed,
please check installation. Periodically
check the 4 PASSENGER AIR BAG OFF
indicator lamp
while driving to make sure it
is illuminated. If the 4 PASSENGER AIR
BAG OFF indicator lamp goes out or
remains out, do not transport a child on the
front-passenger seat.
R A child in a rearward-facing child restraint
system on the front-passenger seat can be
seriously injured or even killed if the front-
passenger air bag is deployed.
R When securing a child in a child restraint
system on the front-passenger seat, you
must:
-move the front-passenger seat as far
back as possible
- use a child restraint system that is
suitable for the age, size and weight of
the child
- observe the manufacturer's installation
instructions in order to install and secure
the child restraint system correctly.
R For children larger than the typical 12-
month-old child, the front-passenger front
air bag may or may not be activated. G
WARNING
Infants and small children should never share
a seat
belt with another occupant. In the event
of an accident, they could be crushed
between the occupant and seat belt.
A child's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint.
Children that are too large for a child restraint
must travel in seats using normal seat belts.
Position the shoulder belt across the chest
and shoulder, not face or neck. A booster seat
may be necessary to achieve proper seat belt 54
Child restraint systems
Safety