warning MERCEDES-BENZ S-Class 2011 W221 Owner's Guide

recommend that you always place a child
in a rear-facing child restraint on the rear
seat.
RIf you install a rear-facing child restraint on
the front-passenger seat, make sure the
42 indicator lamp is
illuminated, indicating that the front-
passenger front air bag is deactivated.
Should the 42 indicator lamp
not illuminate or go out while the restraint
is installed, please check installation.
Periodically check the 42
indicator lamp while driving to make sure
the 42 indicator lamp is
illuminated. If the 42 indicator
lamp goes out or remains out, do not
transport a child on the front-passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates.
RIf you place a child in a forward-facing child
restraint on the front-passenger seat:
-move the seat as far back as possible
-use the proper child restraint
recommended for the age, size and
weight of the child
-secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
RFor children larger than a typical 12-month-
old child, the front-passenger front air bag
can be activated or deactivated.
Deployment of the driver front air bag does
not mean that the front-passenger front air
bag should also have deployed.
OCS may have determined:
Rthat the seat was unoccupied or occupied
by a weight of up to or less than that of a
typical 12-month-old child seated in a
standard child restraint
Rthat the seat was occupied by a small
individual (e.g. a young teenager or a small
adult) or a child who weighs more than a
typical 12-month-old child in a standard
child restraint system
These are examples of when OCS deactivates
the front-passenger front air bag. The air bag
is deactivated despite the impact fulfilling the
criteria for deploying the driver's front air bag.
If the SmartKey has been removed from the
ignition lock or is in position 0, indicator lamp
42: does not light up.
GWarning
If the red SRS 6 indicator lamp in the
instrument cluster and the 42
indicator lamp are lit at the same time, there
is a malfunction in the OCS. The front
passenger front air bag will be deactivated in
this case. Have the system checked by
qualified technicians as soon as possible.
Contact an authorized Mercedes-Benz
Center.
Only have the seat repaired or replaced at an
authorized Mercedes-Benz Center.
In order to ensure proper operation of the air
bag system and OCS:
RSit with the seat belt properly fastened in a
position that is as upright as possible with
your back against the seat backrest.
RWhen seated, a passenger should not
position him/herself in such a way as to
cause the passenger's weight to be lifted
from the seat cushion as this may result in
the OCS being unable to correctly
50Occupant safetySafety

approximate the passenger's weight
category.
R Read and observe all warnings in this
chapter.
System self-test
The 42 indicator lamp
illuminates when you:
R turn the SmartKey to position 1 or 2 in the
ignition lock
R press the KEYLESS-GO Start/Stop button
once or twice
If an adult occupant is properly sitting on the
passenger seat and the OCS classifies the
occupant as an adult, the 42
indicator lamp illuminates and goes out again
after approximately 6 seconds.
If the seat is not occupied and the OCS
classifies the front passenger seat as being
unoccupied, the 4 indicator
lamp 2 will illuminate and not go out.
GWarning!
If the 4 2 indicator lamp does
not illuminate, the system is not functioning.
You must contact an authorized Mercedes-
Benz Center before seating any child on the
front passenger seat.
For more information, see "Problems with the
Occupant Classification System"
( Y page 52).
GWarning
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.Occupant safety51SafetyZ

Problems with the occupant classification systemProblemPossible causes/consequences and M SolutionsThe 42
indicator lamp
illuminates and
remains illuminated.
The person sitting on
the front-passenger
seat:
R weighs as much as a
typical adult
R weighs more than a
childOCS is malfunctioning.XHave OCS checked as soon as possible at an authorized
Mercedes-Benz Center.XObserve the additional display messages in the multifunction
display ( Y page 386).GWarning
If the 42 indicator lamp illuminates and remains illuminated when the weight of a
typical adult or someone larger than a small individual has been detected on the passenger seat,
the system then determines the occupant cannot be a child. Do not allow any occupant to use
the passenger seat until the system has been repaired.
ProblemPossible causes/consequences and M SolutionsThe 42
indicator lamp does not
illuminate and/or does
not remain illuminated.
The front-passenger
seat is:
R unoccupied
R occupied with the
weight of a typical
12-month-old child in
a standard child
restraint or lessOCS is malfunctioning.XMake sure there is nothing between the seat cushion and the
child seat.XCheck the installation of the child restraint system.XMake sure there are no objects applying additional weight onto
the seat.XIf the 42 indicator lamp does not illuminate, have
OCS checked as soon as possible at an authorized Mercedes-
Benz Center. Do not transport a child on the front-passenger
seat until OCS has been repaired.XObserve the additional display messages in the multifunction
display ( Y page 386).GWarning
If the 42 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.
52Occupant safetySafety

PRE-SAFE®
systemGWarning
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.
PRE-SAFE ®
takes pre-emptive measures to
protect occupants in certain hazardous
situations.
PRE-SAFE ®
intervenes:
R in emergency braking situations, e.g. if BAS
is activated or, in vehicles with DISTRONIC
PLUS, where BAS PLUS intervenes
powerfully
R if, on vehicles with DISTRONIC PLUS, the
radar sensor system detects an imminent
danger of collision in certain situations
R in critical driving situations, e.g. when
physical limits are exceeded and the
vehicle understeers or oversteers severely
or when having to swerve to avoid an
obstacle at a speed
PRE-SAFE ®
takes the following measures
depending on the hazardous situation
detected:
R the front seat belts are pre-tensioned.
R the front-passenger seat or the electrically
adjustable outer rear seats are adjusted if
they are in unfavorable position.
R on vehicles with a multicontour seat or an
active multicontour seat: the air pressure
in the side bolsters on the seat cushion and
the side bolsters on the backrest is
increased.
R on vehicles with multicontour seats in the
rear: the air pressure in the backrest side
bolsters of the outer seats in the rear is
increased.
R if the vehicle skids, the sliding sunroof,
panorama sliding sunroof and the side
windows are closed so that only a small gap
remains.
If the sliding sunroof, panorama roof with
power tilt/sliding panel or a side window is
obstructed when closing, the closing
procedure is stopped. The obstructed sliding
sunroof, panorama roof with power tilt/
sliding panel or side window then opens again
slightly.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pretensioning. The air pressure in the
side bolsters on the multicontour seat/active
multicontour seat is reduced again. All
settings made by PRE-SAFE ®
can then be
reversed.
If the seat belts are not released:XMove the backrest back slightly, but only
when the vehicle is stationary.
The belt pretensioning is reduced and the
locking mechanism is released.GWarning
Make sure that nobody can become trapped
as you adjust the seat.
! 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.
More information about seat-belt
adjustment, a convenience function
integrated into PRE-SAFE ®
, can be found in
the "Seat-belt adjustment" section
( Y page 58).
NECK-PRO head restraints/NECK-
PRO luxury head restraints
NECK-PRO head restraints/NECK-PRO luxury
head restraints increase protection of the
driver’s and front-passenger’s head and neck.
Occupant safety53SafetyZ

In the event of a rear collision of a certain
severity, the NECK-PRO head restraints/
NECK-PRO luxury head restraints on the
driver's and the front-passenger seat are
moved forwards and upwards. This provides
better head support.
GWarning
Do not attach any objects (e.g. a coat hanger)
to the NECK-PRO head restraints/NECK-PRO
luxury head restraints. Otherwise, the NECK-
PRO head restraints/NECK-PRO luxury head
restraints may not function properly and in
the event of a rear-end collision may not offer
the protection they are designed to provide.
GWarning
Only use seat covers/head restraint covers
that have been tested and approved by
Mercedes-Benz for your vehicle model.
Using seat covers and head restraint covers
other than those recommended may cause a
malfunction when NECK-PRO head
restraints/NECK-PRO luxury head restraints
are triggered or may prevent side impact air
bags/pelvis air bags from deploying.
Consult an authorized Mercedes-Benz Center
regarding availability.
If the NECK-PRO head restraints/NECK-PRO
luxury head restraints have been triggered in
an accident, reset the NECK-PRO head
restraints/NECK-PRO luxury head restraints
on the driver's and front-passenger seats
(Y page 54). Otherwise, the additional
protection will not be available in the event of
another rear-end collision. NECK-PRO head
restraints/NECK-PRO luxury head restraints
that have been triggered are moved forwards
and can no longer be adjusted.
GWarning!
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
at eye level. This will reduce the potential for
injury to the head and neck in the event of an
accident or similar situation.
Resetting triggered NECK-PRO head
restraints
Important safety notes
GWarning
For reasons of safety, have the NECK-PRO
head restraints/NECK-PRO luxury head
restraints checked at an authorized
Mercedes-Benz Center after a rear-end
collision.
GWarning
When pushing back the NECK-PRO head
restraint cushion, make sure your fingers do
not become caught between the head
restraint cushion and the cover. Failure to
observe this could result in injuries.
NECK-PRO head restraints
iResetting the NECK-PRO head restraints
requires a lot of strength. If you have
difficulty resetting the NECK-PRO head
restraints, have this work carried out at a
qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center.
54Occupant safetySafety

XPress the base of the NECK-PRO head
restraint cushion back in the direction of
arrow ; as far as it will go.
XPush the NECK-PRO head restraint cushion
down into the guide in the direction of
arrow = as far as it will go.
XFirmly fold the NECK-PRO head restraint
cushion back in the direction of arrow :
until it engages.
XRepeat this procedure for the second
NECK-PRO head restraint.
NECK-PRO luxury head restraints
iIf you have difficulty resetting the NECK-
PRO luxury head restraints, have this work
carried out at a qualified specialist
workshop, e.g. a Mercedes Benz Service
center.
XRemove resetting tool : from the vehicle
tool kit in the trunk.
XSlide resetting tool : into guide ;
between the NECK-PRO luxury head
restraint and the rear cover of the head
restraint.
XPush resetting tool : downwards until you
hear the head restraint deployment
mechanism engage.
XPull out resetting tool :.XFirmly press the NECK-PRO luxury head
restraint cushion back = until it engages.
XRepeat this procedure for the second
NECK-PRO luxury head restraint.
XPut resetting tool : back into the vehicle
tool kit.
Seat belts
Important safety notes
The use of seat belts and infant and child
restraint systems is required by law in all 50
states, the District of Columbia, the U.S.
territories and all Canadian provinces.
Even where this is not the case, all vehicle
occupants should have their seat belts
fastened when the vehicle is in motion.
iSee "Children in the vehicle"
(Y page 60) for more information on
infants and children traveling with you in
the vehicle and restraints for infants and
children.
GWarning!
Always fasten your seat belt before driving off.
Always make sure all of your passengers are
properly restrained. You and your passengers
should always wear seat belts.
Failure to wear and properly fasten and
position your seat belt greatly increases your
risk of injuries and their likely severity in an
accident.
If you are ever in an accident, your injuries can
be considerably more severe without your
seat belt properly buckled. Without your seat
belt buckled, you are much more likely to hit
the interior of the vehicle or be ejected from
it. You can be seriously injured or killed.
In the same crash, the possibility of injury or
death is lessened if you are properly wearing
your seat belt. The air bags can only protect
as intended if the occupants are properly
wearing their seat belts.
GWarning
Never ride in a moving vehicle with the seat
backrest in an excessively reclined position as
Occupant safety55SafetyZ

this can be dangerous. You could slide under
the seat belt in a collision. If you slide under
it, the seat belt would apply force at the
abdomen or neck. That could cause serious
or even fatal injuries. The seat backrest and
seat belt provide the best restraint when the
wearer is in a position that is as upright as
possible and the seat belt is properly
positioned on the body.GWarning
Never let more people ride in the vehicle than
there are seat belts available. Make sure
everyone riding in the vehicle is correctly
restrained with a separate seat belt. Never
use a seat belt for more than one person at a
time.
GWarning
Damaged seat belts or seat belts that have
been subjected to stress in an accident must
be replaced and their anchoring points must
also be checked.
Only use seat belts which have been approved
by Mercedes-Benz.
Do not make any modifications to the seat
belts. This can lead to unintended activation
of the ETDs or to their failure to activate when
necessary.
Do not bleach or dye seat belts as this may
severely weaken them. In a crash they may
not be able to provide adequate protection.
Have all work carried out only by qualified
technicians. Contact an authorized
Mercedes-Benz Center.
Correct use of the seat belt
GWarning
USE SEAT BELTS PROPERLY
R Seat belts can only work when used
properly. Never wear seat belts in any other
way than as described in this section, as
that could result in serious injuries in the
event of an accident.
R Each occupant should wear their seat belt
at all times, because seat belts help reduce
the likelihood of and potential severity of
injuries in accidents, including rollovers.
The integrated restraint system includes
SRS (driver front air bag, front-passenger
front air bag, side impact air bags, window
curtain air bags for the side windows),
Emergency Tensioning Devices, seat belt
force limiters, and front seat knee bolsters.
The system is designed to enhance the
protection offered to properly belted
occupants in certain frontal (front air bags
and ETDs) and side (side impact air bags,
window curtain air bags, and ETDs) impacts
which exceed preset deployment
thresholds and in certain rollovers (window
curtain air bags and ETDs).
R Never wear the shoulder belt under your
arm, across your neck or off your shoulder.
In a frontal crash, your body would move
too far forward. That would increase the
chance of head and neck injuries. The seat
belt would also apply too much force to the
ribs or abdomen, which could severely
injure internal organs such as your liver or
spleen.
Adjust the seat belt so that the shoulder
section is located as close as possible to
the middle of the shoulder. It should not
touch the neck. Never pass the shoulder
portion of the seat belt under your arm. For
this purpose, you can adjust the height of
the seat belt outlet.
R Position the lap belt as low as possible on
your hips and not across the abdomen. If
the lap belt is positioned across your
abdomen, it could cause serious injuries in
a crash.
R Never wear seat belts over rigid or
breakable objects in or on your clothing,
such as eyeglasses, pens, keys etc., as
these might cause injuries.56Occupant safetySafety

RMake sure the seat belt is always routed
snugly. Take special care of this when
wearing loose clothing.
RNever use a seat belt for more than one
person at a time. Do not fasten a seat belt
around a person and another person or
other objects at the same time.
RSeat belts should not be worn twisted. In a
crash, you would not have the full width of
the seat belt to distribute impact forces.
The twisted seat belt against your body
could cause injuries.
RPregnant women should also always use a
lap-shoulder belt. The lap belt portion
should be positioned as low as possible on
the hips to avoid any possible pressure on
the abdomen.
RPlace the seat backrest in a position that is
as upright as possible.
RCheck your seat belt during travel to make
sure it is properly positioned.
RNever place your feet on the instrument
panel, dashboard, or on the seat. Always
keep both feet on the floor in front of the
seat.
RWhen using a seat belt to secure infant
restraints, toddler restraints, or children in
booster seats, always follow the child seat
manufacturer's instructions.
GWarning
Do not pass seat belts over sharp edges. They
could tear.
Do not allow the seat belt to get caught in the
door or in the seat adjustment mechanism.
This could damage the seat belt.
Never attempt to make modifications to seat
belts. This could impair the effectiveness of
the seat belts.
Fastening seat belts
GWarning
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seat whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child. For additional information, see the
"Children in the vehicle" section.
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.
XAdjust the seat and move the backrest to
an almost vertical position (Y page 100).
XPull the seat belt smoothly through belt
sash guide :.
XWithout twisting it, guide the shoulder
section of the seat belt across the middle
of your shoulder and the lap section across
your hips.
Occupant safety57SafetyZ

XEngage 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 58).
XIf necessary, adjust the seat belt to the
appropriate height (Y page 58).
XIf necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
All seat belts in the vehicle, except the
driver's seat belt, are equipped with a special
seat belt retractor to secure child restraint
systems properly. For further information on
"Special seat belt retractors", see
(Y page 62).
For more information about releasing the seat
belt with release button ?, see "Releasing
seat belts" (Y page 58).
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:
Ryou engage the belt tongue in the belt
buckle and you then turn the SmartKey to
position 2 in the ignition lock.
Rthe 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 certain
tightening 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 378).
Seat belt outlet height adjustment
You can adjust the seat belt height on the
driver's seat and the front-passenger seat.
Adjust the height so that the upper part of the
seat belt is routed across the center of your
shoulder.
XTo raise: slide the belt sash guide upwards.
The belt sash guide engages in various
positions.
XTo lower: press and hold belt sash guide
release :.
XSlide the belt sash guide downwards.XRelease belt sash guide release : and
make sure that the belt sash guide has
engaged.
The outer seat belts in the rear compartment
are adjusted automatically.
Releasing seat belts
XPress release button ? (Y page 57) and
guide belt tongue ; back towards belt
sash guide :.
! 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. Consult an authorized Mercedes-
Benz Center.
Belt warning for driver and front
passenger
Regardless of whether the driver's and front-
passenger seat belts have already been
58Occupant safetySafety

fastened, the 7 seat belt warning lamp
lights up for six seconds each time the engine
is started. It then goes out once the driver and
the front passenger have fastened their seat
belts.
If the driver's seat belt is not fastened after
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.
If, after six seconds, the driver or front-
passenger have not fastened their seat belts
and the doors are closed:
R the 7 seat belt warning lamp remains
illuminated as long as either the driver's or
front-passenger seat belt is not fastened.
R if the vehicle speed exceeds 15 mph
(25 km/h), the 7 seat belt warning
lamp lights up. Additionally, a warning tone
will sound with increasing intensity for a
maximum of 60 seconds or until the
driver's and front-passenger seat belt are
fastened.
If the driver/front passenger unfasten their
seat belt while the vehicle is in motion, the
7 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 7 seat belt
warning lamp stops flashing but remains
illuminated.
After the vehicle comes to a standstill, the
warning tone is reactivated and the 7 seat
belt warning lamp flashes again if the vehicle
speed again exceeds 15 mph (25 km/h) .
The 7 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 7 seat
belt warning lamp, see "Indicator andwarning lamps in the instrument cluster,
seat belt" ( Y page 414).
Emergency Tensioning Devices and
seat belt force limiters
The front seat belts and the outer seat belts
in the rear are equipped with ETDs and belt
force limiters.
! 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 belt tensioners tighten the seat belts in
an accident, pulling them close against the
body.
Belt tensioners do not correct incorrect seat
positions or incorrectly fastened seat belts.
Belt tensioners do not pull vehicle occupants
back towards the backrest.
Seat belt force limiters, when triggered, help
to reduce the peak force exerted by the seat
belt on the vehicle occupant.
The front 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 belt tensioners can only be activated
when:
R the ignition is switched on.
R the restraint systems are operational; see
"SRS warning lamp" ( Y page 42).
R the belt tongue is engaged in the buckle on
each of the three-point seat belts in the
front.
R the front-passenger seat is occupied and
the belt tongue is engaged in the buckle on
the front-passenger side.
The belt tensioners on the outside seats in the
rear compartment are triggered
independently of the lock status of the seat
belts.
Occupant safety59SafetyZ