belt MERCEDES-BENZ S CLASS 2017 Owner's Manual

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
Emergency Tensioning Devices that have
deployed pyrotechnically 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.
Have pyrotechnically triggered Emergency
Tensioning Devices replaced immediately 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 43) 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.
Vehicles with belt bags: the belt bags are also
deployed depending on the type and severity of
the accident.
Vehicles with a rear reclining seat: the Emer-
gency Tensioning Device is only triggered if the
belt buckle tongue is engaged in the belt buckle.
If the seat backrest is reclined, the cushion air
bag will also be deployed depending on the type
and severity of the accident.
If the restraint system control unit detects a
more severe accident, further components of
t h e 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 OFF indicator lamp is off.
Observe the information on the PASSENGER AIR
BAG indicator lamps ( Y
page 43).
Your vehicle has two-stage front air bags. During
the first deployment stage, the front air bag is
filled 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 in
the vehicle. This process is pre-emptive in
nature. Deployment should take place in good
time at the start of the collision.56
Occupant safety
Safety

The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by: R
the distribution of forces during the collision R
the collision angle R
the deformation characteristics of the vehicle R
the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a deci-
sive role in the deployment of an air bag. Nor do
they provide an indication of air bag deploy-
ment.
The vehicle can be deformed considerably, with-
out an air bag being deployed. This is the case if
only parts which are relatively easily deformed
are affected and the rate of deceleration is not
high. Conversely, air bags may be deployed even
though the vehicle suffers only minor deforma-
tion. This is the case if, for example, very rigid
vehicle parts such as longitudinal body mem-
bers are hit, and sufficient deceleration occurs
as a result.
If the restraint system control unit detects a side
impact or if the vehicle rolls over, the applicable
components of the restraint system are activa-
ted independently of each other depending on
the apparent type of accident. R
Side impact air bags on the side where the
impact takes place, independently of the
Emergency Tensioning Device and the use of
the seat belt on the driver's seat and outer
seats in the second row
The side impact air bag 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 is engaged in the belt
buckle of the front-passenger seat R
Window curtain air bag on the side of impact,
independently of the use of the seat belt and
independently of whether the front-
passenger seat is occupied R
Emergency Tensioning Devices, if the system
determines that deployment can offer addi-
tional protection in this situation R
Window curtain air bags on the driver's and
front-passenger side in certain situations
when the vehicle rolls over, if the system
determines that deployment can offer addi- tional protection to that provided by the seat
belt
i Not all air bags are deployed in an accident .
The different air bag systems work independ-
ently of each other.
How the air bag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or accel-
eration and the apparent type of accident: R
Frontal collision R
Side impact R
Rollover
PRE-SAFE ®
(anticipatory occupant
protection system)
Introduction In certain hazardous situations, PRE-SAFE ®
takes pre-emptive measures to protect the vehi-
cle occupants.
Important safety notes
! Make sure that there are no objects in the
footwell or behind the seats. There is a danger
that the seats and/or objects could be dam-
aged when PRE-SAFE ®
is activated.
Despite your vehicle being equipped with the
PRE-SAFE ®
system, the possibility of personal
injuries occurring as a result of an accident can-
not be eliminated. 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 physi-
cal limits are exceeded and the vehicle under-
steers or oversteers severely R
vehicles with the Driving Assistance package:
when a driver assistance system intervenes
powerfully or the radar sensor system detects
an imminent danger of collision in certain sit-
uationsOccupant 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
panorama roof with power tilt/sliding panel
are closed. R
the front-passenger seat is adjusted if it is in
an unfavorable position. R
for vehicles with electrically adjustable rear
seats: the outer rear seats are adjusted if they
are in an unfavorable position. R
vehicles with a multicontour seat: the air pres-
sure in the side bolsters of the seat backrest
is increased. R
vehicles with seat belt extenders: the seat
belts of the outer rear seats are pre-ten-
sioned.
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 47).
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 when PRE-SAFE ®
PLUS
intervenes.
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 unlocked58
Occupant safety
Safety

R
the front side windows are lowered R
the electrically adjustable steering wheel is
raised R
the engine is switched off and the fuel supply
is cut off R
vehicles with seat belt extenders: the seat-
belt buckles for the outer rear seats are illu-
minated and extend forwards R
vehicles with mbrace: automatic emergency
call
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 51)
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 44) and the notes on correct use of seat
belts ( Y
page 45).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lb s( 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. ReactivateChildren in the vehicle 59
Safety Z

the special seat belt retractor and secure the
child restraint system properly.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor.
When activated, the special seat belt retractor
ensures that the seat belt will not slacken once
the child restraint system has been secured.
Installing a child restraint system: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Pull the seat belt smoothly from the belt out-
let. X
Engage the seat belt tongue in the 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 activated. X
Push the child seat restraint system down so
that the seat belt is tight and does not loosen.
Removing a child restraint system and deacti-
vating the special seat belt retractor: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Press the release button of the belt buckle,
hold the belt tongue firmly and guide it back
to w ards the belt outlet.
The special seat belt retractor is deactivated.
Child restraint system 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
You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
G WARNING
If the child restraint system is installed incor-
rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained
in the event of an accident, heavy braking or sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under
or behind the child restraint system. Only use
child restraint systems with the original cover
designed for them. Only replace damaged
covers with genuine covers.
G WARNING
If the child restraint system is installed incor-
rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik-
ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
You will find further information on stowing
objects, luggage or loads under "Loading guide-
lines" ( Y
page 281).
G WARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjected
to a load in an accident can no longer protect
as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction. There
is an increased risk of injury, possibly even
fatal.
Replace child restraint systems which have
been damaged or subjected to a load in an
accident as soon as possible. Have the secur-
ing systems on the child restraint system
checked at a qualified specialist workshop,
before you install a child restraint system
again.60
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 51). 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.
Vehicles with seat belt extenders: when
securing a child in a child restraint system on a
rear seat, observe the following instructions: R
make sure that the seat belt on the child
restraint system is fastened according to the
manufacturer's installation instructions for
the child restraint system. R
for child restraint systems with a belt clamp:
engage the belt tongue in the buckle before
you tighten the seat belt using the belt clamp.
Vehicles with a rear reclining seat: when
installing a child restraint system, move the rear
reclining seat backrest to an almost vertical
position. The rear reclining seat backrest must
rest against the child restraint system. Observe
the notes on the cushion air bag ( Y
page 50).
Vehicles with belt bags: only use a child
restraint system which has been approved by
Mercedes-Benz. Always observe the instruc-
tions and safety notes on belt bags for the outer
seat belts in the rear ( Y
page 46). 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 D on the
rear seats are covered by a Velcro-fastened
upholstered lining C .X
Vehicles with a rear reclining seat: adjust
the rear reclining seat backrest down a littleChildren in the vehicle 61
Safety Z

before installing the LATCH-type (ISOFIX)
child restraint system. X
Vehicles without rear reclining seat: fold
upholstered lining C upwards.X
Vehicles with a rear reclining seat: remove
upholstered lining C .X
Vehicles without a rear reclining seat: turn
the support on the rear side of upholstered
lining C by 90°.
Upholstered lining C remains folded
upwards. X
Install the LATCH-type (ISOFIX) child restraint
system on both LATCH-type (ISOFIX) securing
rings D .X
Vehicles with a rear reclining seat: move
the rear reclining seat backrest to an upright
position. The rear reclining seat backrest
must rest against the child restraint system.
G WARNING
Vehicles with electrically adjustable rear
bench seats:
If you adjust the seat after installing a child
restraint system: R
the seat belt could slacken or become too
tight R
the child restraint system could become
loose, incorrectly positioned or damaged
As a result, the child restraint system may not
be able to provide the intended level of pro-
tection. This poses an increased risk of injury
or even fatal injury.
Never adjust the seat after installing the child
restraint system.
Vehicles without rear reclining seat: after
you have removed the LATCH-type (ISOFIX)
child restraint system, you must turn the sup-
port on the rear side of upholstered lining C by
90° again. Then fold upholstery lining C down.
ISOFIX is a standardized securing system for
specially designed child restraint systems on
the rear seats. LATCH-type (ISOFIX) securing
rings D for two LATCH-type (ISOFIX) child
restraint systems are installed on the left and
right rear seats.
Vehicles with rear seat armrest: adjust the
rear seat armrest so that LATCH-type (ISOFIX)
securing rings D for the LATCH-type (ISOFIX)
child restraint system are accessible. 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-
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. Observe the lock veri-
fication indicator. Adjust the rear seat backr-
ests so that they are in an upright position.
G WARNING
Vehicles with electrically adjustable rear
bench seats:
If you adjust the seat after installing a child
restraint system: R
the seat belt could slacken or become too
tight R
the child restraint system could become
loose, incorrectly positioned or damaged
As a result, the child restraint system may not
be able to provide the intended level of pro-
tection. This poses an increased risk of injury
or even fatal injury.62
Children in the vehicle
Safety

Never adjust the seat after installing the child
restraint system.
If the rear seat backrest is not engaged and
locked, this will be shown in the multifunction
display in the instrument cluster. A warning tone
also sounds.
Top Tether anchorages
The Top Tether anchorage points are installed in
the rear compartment behind the head
restraints on the parcel shelf.
X
Move the head restraint up ( Y
page 111).X
Fold up cover C of the Top Tether anchorage.X
Install the LATCH-type (ISOFIX) child restraint
system with Top Tether. Always comply with
the child restraint system manufacturer's
installation instructions when doing so. X
Route Top Tether belt

of the child restraint system must always rest on
the seat cushion of the front-passenger seat.
The backrest of the 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. Always make sure that the shoul-
der belt strap is correctly routed from the vehi-
cle belt outlet to the shoulder belt guide on the
child restraint system. The shoulder belt strap
must be routed forwards and downwards from
the vehicle belt outlet. If necessary, adjust the
vehicle belt outlet and the front-passenger seat
accordingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Child-proof locks
Important safety notes
G WARNING
If children are traveling in the vehicle, they
could: R
open doors, thus endangering other people
or road users R
exit the vehicle and be caught by oncoming
traffic R
operate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the
vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle.
Override feature for: R
the rear doors ( Y
page 65)R
the rear side windows ( Y
page 65) 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.64
Children in the vehicle
Safety

Correct driver's seat position
G WARNING
You could lose control of your vehicle if you do
the following while driving: R
adjust the driver's seat, head restraint,
steering wheel or mirrors R
fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt
before starting the engine.
Observe the following when adjusting steering
wheel C , seat belt D and driver's seat