Page 49 of 349

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 seat
belt tensioners in the event of a head-on or rear collision.
A seat belt tensioner 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 38)
R the belt tongue has engaged in the belt buckle
of the respective front seat
The seat belt tensioners in the rear compart-
ment are triggered independently of the lock
status of the seat belts.
If the restraint system control unit detects a high severity accident, in certain head-on collisions,
additional components of the restraint system
are deployed independently of each other:
R front airbags and driver's kneebag
R headbag, if the system determines that
deployment can offer additional protection to
that provided by the seat belt
Depending on the person in the front-passenger seat, the front-passenger front airbag is either
disabled or enabled. The front-passenger front
airbag can only be deployed in an accident if the
PASSENGER AIR BAG OFF indicator lamp is off. Observe the information on the PASSENGER AIR
BAG OFF indicator lamp (Y page 38).
Your vehicle has two-stage front airbags. In the
first deployment stage, the front airbag is filled
with propellant gas to reduce the risk of injuries. The front airbag is fully deployed if the second
deployment stage is activated within a few mil-
liseconds.
The activation threshold for the seat belt ten-
sioners and airbags is determined based on the evaluation of the vehicle's rate of deceleration
or acceleration at various points in the vehicle.
This process is pre-emptive in nature. The trig-
gering/deployment process should take place
in good time at the start of the collision. 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 airbag, nor do they provide an indication of airbag deployment.
The vehicle may be deformed significantly with- out an airbag 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, an airbag may be deployed
even though the vehicle suffers only minor
deformation. This is the case if, for example,
very rigid vehicle parts such as longitudinal body
members are hit, and sufficient deceleration
occurs as a result.
If the restraint system control unit detects a side impact or if the vehicle overturns, the applicablecomponents of the restraint system are activa-
ted independently of each other depending on
the apparent type of accident.
R Sidebags and pelvisbag on the side on which
an impact occurs, independent from the seat
belt tensioner and seat belt usage
Vehicles with the automatic child seat recog-
nition on the front-passenger seat: the side-
bag and pelvisbag on the front-passenger side (front) deploy under the following conditions:
- an occupant is detected on the front-
passenger seat or
- the belt tongue is engaged in the belt
buckle of the front-passenger seat
R Headbag on the side on which an impact
occurs, independent of seat belt usage and
regardless of whether the front-passenger
seat is occupied
R Seat belt tensioners, if the system determines
that deployment can offer additional protec-
tion for the vehicle occupants in this situation
R Headbags on the driver's and front-passenger
side in certain situations if the vehicle over-
turns and if the system determines that
deployment can offer additional protection to that provided by the seat belt 46
Occupant safetySafety
Page 50 of 349

i
Not all airbags are deployed in an accident.
The different airbag systems work independ-
ently of each other.
How the airbag 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 overturn NECK-PRO head restraints
Important safety notes G
WARNING
The function of the head restraint may be
impaired if you:
R attach objects such as coat hangers to the
head restraints, for example
R use unsuitable head restraint covers
If you do so, the head restraints cannot fulfil
their intended protective function in the event of an accident. In addition, objects attached
to the head restraints could endanger other
vehicle occupants. This poses an increased
risk of injury.
Do not attach any objects to the head
restraints and only use suitable head restraint
covers.
Consult a Mercedes-Benz Service Centre
regarding the availability of suitable seat or head
restraint covers.
Operation NECK-PRO head restraints reduce the likelihood
of head and chest injuries. The NECK-PRO head
restraints on the driver's and front-passenger
seats are moved forwards and upwards in the
event of a rear-end collision of a certain severity. This provides better head support.
If the NECK-PRO head restraints have been trig-
gered in an accident, you must reset the NECK-
PRO head restraints on the driver's and front-
passenger seat (Y page 47). Otherwise, the
additional protection will not be available in the
event of another rear-end collision. You can rec- ognise when NECK-PRO head restraints have
been triggered by the fact that they have moved
forwards and can no longer be adjusted.
Mercedes-Benz recommends that you have the
NECK-PRO head restraints checked for func-
tionality at a qualified specialist workshop after a rear-end collision.
Resetting triggered NECK-PRO head
restraints Do not place your fingers between the uphols-
tery of the head restraint and the seat. Pay par-
ticular attention while resetting the NECK-PRO
head restraints.
X Tilt the top of the NECK-PRO head restraint
cushion forwards in the direction of arrow :.
X Push the NECK-PRO head restraint cushion
down as far as it will go in the direction of
arrow ;.
X Firmly push the NECK-PRO head restraint
cushion back in the direction of arrow =until
the cushion engages.
X Repeat this procedure for the second NECK-
PRO head restraint.
i Resetting the NECK-PRO head restraints
requires a lot of strength. If you have difficulty
resetting the NECK-PRO head restraints, have this work carried out at a qualified specialist
workshop. PRE-SAFE
®
(anticipatory occupant
protection)
Introduction In certain hazardous situations, PRE-SAFE
®
takes pre-emptive measures to protect the vehi- cle occupants. Occupant safety
47Safety Z
Page 51 of 349

Important safety notes
!
Make sure that there are no objects in the
footwell or behind the seats. There is a risk
that the seats and/or the objects could be
damaged when PRE-SAFE ®
is activated.
Although your vehicle is equipped with PRE-
SAFE ®
, the possibility of injury in the event of an
accident cannot be ruled out. Always adapt your
driving style to suit the prevailing road and
weather conditions and maintain a safe distance from the vehicle in front. Drive carefully.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when physi-
cal limits are exceeded and the vehicle under- steers or oversteers severely
R on vehicles with the Driving Assistance pack-
age: if BAS PLUS intervenes powerfully or the
radar sensor system detects an imminent
danger of collision in certain situations
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 front side windows are
closed
R vehicles with the memory function: the front-
passenger seat is adjusted if it is in an unfav-
ourable position
R vehicles with a multicontour seat: the air pres-
sure in the side bolsters of the 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.
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 41). PRE-SAFE
®
PLUS (anticipatory occu-
pant protection 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 before the intervention
of PRE-SAFE ®
PLUS.
PRE-SAFE ®
PLUS does not intervene:
R if the vehicle is reversing
R when the vehicle is towing a trailer and there
is a risk of a rear-end collision
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 rear hazard warning lamps are activa-
ted and flash at a higher frequency
- the brake pressure is increased if the driver
applies the brakes when the vehicle is sta-
tionary
- the seat belts are pre-tensioned 48
Occupant safetySafety
Page 52 of 349

The PRE-SAFE
®
PLUS braking application is can-
celled:
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 may be 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 off
R vehicles with the Mercedes-Benz emergency
call system: 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 seats. For this reason, Mercedes-
Benz strongly advises that you fit a child
restraint system on a rear seat. Children are
generally better protected there.
If a child younger than twelve years old and
under 1.50 m in height is travelling in the vehi-
cle:
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. G
WARNING
If you leave children unattended in the vehi-
cle, they may be able to set the vehicle in
motion if, for example, they:
R release the parking brake
R shift the automatic transmission out of park
position Por shift manual transmission into
neutral
R start the engine
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children unattended in the vehicle. G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there is a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle. G
WARNING
If the child restraint system is placed in direct sunlight, the parts could become very hot.
Children could be suffer burns by touching
these parts, in particular on the metallic parts
of the child restraint system. There is a risk of injury.
If you and your child leave the vehicle, always
make sure that the child restraint system is
not in direct sunlight. Cover it with a blanket, for example. If the child restraint system has
been exposed to direct sunlight, leave it to
cool down before securing the child in it.
Never leave children unattended in the vehi-
cle.
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 39) and the notes on how to use the seat
belt properly (Y page 40). Children in the vehicle
49Safety Z
Page 53 of 349

Child seat lock
G
WARNING
If the seat belt is released while driving, the
child restraint system will no longer be
secured properly. The child seat lock is disa-
bled and the inertia real draws in a portion of
the seat belt. The seat belt cannot be imme-
diately 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 child seat lock and secure the child
restraint system properly.
The rear seat belts are equipped with a child
seat lock. When enabled, the child seat lock
function ensures that the seat belt does not
slacken once the child restraint system is
secured.
Installing a child restraint system:
X Always comply with the child restraint system
manufacturer's installation instructions.
X Pull the seat belt smoothly out the belt outlet.
X Engage the seat belt tongue in the belt buckle.
Activating the child seat lock: 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 child seat lock
function is enabled.
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 child seat lock:
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
towards the belt outlet.
The child seat lock function is deactivated. Child restraint system
Be sure to observe the correct use of the child
restraint system (Y page 55).
For safety reasons, Mercedes-Benz recom-
mends that you only use a child restraint system recommended by Mercedes-Benz
(Y
page 58). G
WARNING
If the child restraint system is incorrectly fit-
ted on the seat position suitable for this pur-
pose, it cannot perform its intended protec-
tive function. In the event of an accident,
sharp braking or a sudden change in direction, the child may not be held securely. There is an
increased risk of serious or even fatal injuries.
Observe the manufacturer's installation
instructions and the correct use for the child
restraint system. Make sure that the entire
surface of the child restraint system is resting
on the seat surface. Never place objects
under or behind the child restraint system,
e.g. cushions. Only use child restraint sys-
tems with the original cover designed for
them. Only replace damaged covers with gen- uine covers. G
WARNING
If the child restraint system is fitted 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 fit child restraint systems properly,
even if they are not being used. Make sure
that you observe the child restraint system
manufacturer's installation instructions.
You will find further information on stowing
objects, luggage and loads securely under
"Loading guidelines" (Y page 272). G
WARNING
Child restraint systems or their securing sys-
tems that have been damaged or subjected to a load in an accident cannot perform their
intended protective function. In the event of
an accident, sharp braking or a sudden
change in direction, the child may not be held securely. There is an increased risk of serious
or even fatal injuries. 50
Children in the vehicleSafety
Page 54 of 349

Immediately replace child restraint systems
that have been damaged or subjected to a
load in an accident. Have the child restraint
securing systems checked in a qualified spe-
cialist workshop before fitting a child restraint
system again.
Securing systems for child restraint systems
include:
R the seat belt system
R the ISOFIX securing rings
If it is absolutely necessary to fit a child restraint system on the co-driver's seat, be sure to
observe the notes on "Child restraint systems
on the co-driver's seat" (Y page 53). Informa-
tion about deactivating the co-driver's front air- bag can also be found there.
Observe the warning labels in the vehicle inte-
rior and on the child restraint system.
i It is advisable to use Mercedes-Benz care
products to clean child restraint systems rec- ommended by Mercedes-Benz. You can
obtain information at a qualified specialist
workshop. ISOFIX child seat securing system
G
WARNING
ISOFIX child restraint systems do not offer
sufficient protective effect for children whose weight is greater than 22 kg who are securedusing the safety belt integrated in the child
restraint system. The child could, for example, not be restrained correctly in the event of an
accident. This poses an increased risk of
injury or even fatal injury.
If the child weighs more than 22 kg, only use
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 observe the notes on using the child
restraint system (Y page 55) as well as the
installation and operating instructions provided
by the manufacturer for the child restraint sys-
tem being used. Before each journey, make sure that the ISOFIX
child restraint system is properly engaged in
both ISOFIX securing rings. ISOFIX securing rings
:are located between
the seat cushion and the seat backrest.
X Install the ISOFIX child restraint system on
both ISOFIX securing rings :.
ISOFIX is a standardised securing system for
special child restraint systems on the rear seats.
ISOFIX securing rings for two ISOFIX child
restraint systems are fitted on the left and right of the rear seats.
Mercedes-Benz recommends the use of the lis-
ted ISOFIX child restraint systems together with the insertion guides included (Y page 58).
Using insertion guides makes it easier to fit ISO- FIX child restraint systems.
Secure child restraint systems without an ISO-
FIX child seat securing system using the seat
belts in the vehicle. Always observe the notes on
using the child restraint system (Y page 55) as
well as the installation and operating instruc-
tions provided by the manufacturer for the child restraint system being used. Automatic child seat recognition on
the front-passenger seat
The sensor system for the automatic child seat
recognition in the front-passenger seat detects
whether a special Mercedes-Benz child restraint system with transponders has been fitted. In
this case, the PASSENGER AIR BAG OFF indica-
tor lamp lights up and remains lit. The front-
passenger front airbag is disabled. Children in the vehicle
51Safety Z
Page 55 of 349

i
If the front-passenger front airbag is disa-
bled by the automatic child seat recognition,
the following remain enabled on the front-
passenger side:
R the sidebag
R the pelvisbag
R the headbag
R the belt tensioner G
WARNING
If you secure a child in a child restraint system on the front-passenger seat and the
PASSENGER AIR BAG OFF indicator lamp is
off, the front-passenger front airbag can
deploy in the event of an accident. The child
could be struck by the airbag. This poses an
increased risk of injury or even fatal injury.
Make sure that the front-passenger front air-
bag has been disabled. The PASSENGER AIR- BAG OFF indicator lamp must be lit. G
WARNING
If the PASSENGER AIRBAG OFF indicator lamp is lit, the front-passenger front airbag is disa-
bled. It will not be deployed in the event of an
accident and cannot perform its intended pro-
tective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
In this case the front-passenger seat may not be used. You may only transport a child on the
front-passenger seat if they are seated in a
suitable rearward or forward-facing child
restraint system. Always observe the infor-
mation about suitable positioning of the child restraint system in this Owner's Manual as
well as the child restraint system manufac-
turer's installation instructions. G
WARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too close to the dashboard, in the event of an
accident, the child could:
R come into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example
R be struck by the airbag if the PASSENGER
AIR BAG OFF indicator lamp is off
This poses an increased risk of injury or even fatal injury.
Move the front-passenger seat as far back as
possible. Always make sure that the shoulder belt strap is correctly routed from the vehicle
seat-belt extender to the shoulder belt guide
on the child restraint system. The shoulder
belt strap must be routed forwards and down-
wards from the retracted seat-belt extender.
If necessary, adjust the front-passenger seat
accordingly. Always observe the information
about suitable positioning of the child
restraint system in this Owner's Manual as
well as the child restraint system manufac-
turer's installation instructions.
i Ensure that your vehicle is equipped with
automatic child seat recognition for the front-
passenger seat (Y page 53). If this is not the
case, always install a child restraint system on a suitable rear seat (Y page 55).52
Children in the vehicleSafety
Page 56 of 349

PASSENGER AIR BAG OFF indicator lamp
:
shows you whether the front-passenger front
airbag is disabled.
X Turn the key to position 1or 2in the ignition
lock or, on vehicles with KEYLESS-GO, press
the Start/Stop button once or twice.
The system carries out a self-diagnosis.
The PASSENGER AIR BAG OFF indicator lamp
must light up for approximately six seconds.
If, after the system self-test, the
PASSENGER AIR BAG OFF indicator lamp:
R lights up , the front-passenger front airbag is
disabled. It will then not be deployed in the
event of an accident.
R is not lit , the sensor system did not detect a
child restraint system with transponder for
automatic child seat recognition. If, in the
case of an accident, all deployment criteria
are met, the front-passenger front airbag is
deployed. G
WARNING
Electronic devices on the front-passenger
seat can affect the function of the automatic
child seat recognition, for example:
R laptop
R mobile phone
R transponder cards such as ski passes or
access passes
The front-passenger front airbag could deploy unintentionally or not function as intended
during an accident. This poses an increased
risk of injury or even fatal injury.
Do not place any of the devices mentioned
above or similar devices on the front-
passenger seat. Be aware of the status of the front-passenger front airbag both before and
during the journey. Child restraint system on the front-
passenger seat
General notes Accident statistics show that children secured
in the rear seats are safer than children secured
in the front seats. For this reason, Mercedes- Benz strongly advises that you fit a child
restraint system on a rear seat.
Vehicles with automatic child seat recognition
on the co-driver's seat: if it is absolutely neces-
sary to fit a child restraint system to the co-driv- er's seat, always observe the notes on "Auto-
matic child seat recognition on the co-driver's
seat" (Y page 53).
You can thus avoid the risks that could arise as
a result of:
R a child restraint system that is not detected
by the automatic child seat recognition's sen-
sor system
R the unintentional disabling of the co-driver's
front airbag
R the unsuitable positioning of the child
restraint system, e.g. too close to the dash-
board. Please observe the warning notice on the co-
driver's sun visor, see the illustration. G
WARNING
If you secure a child in a child restraint system on the front-passenger seat and the
PASSENGER AIR BAG OFF indicator lamp is
off, the front-passenger front airbag can
deploy in the event of an accident. The child
could be struck by the airbag. This poses an
increased risk of injury or even fatal injury.
Make sure that the front-passenger front air-
bag has been disabled. The PASSENGER AIR-BAG OFF indicator lamp must be lit.
NEVER use a rearward-facing child restraint on a seat protected by an ACTIVE AIRBAG in front of
it, DEATH or SERIOUS INJURY to the CHILD can
occur. Children in the vehicle
53Safety Z