Occupant Classification System
(OCS)
Introduction
The Occupant Classification System (OCS)
categorizes the person in the front-passenger
seat. Depending on that result, the front-
passenger front air bag is either enabled or
deactivated.
The system does not deactivate:
Rthe side impact air bag
Rthe pelvis air bag
Rthe window curtain air bag
Rthe Emergency Tensioning Devices
Prerequisites
To be classified correctly, the front passenger
must sit:
Rwith the seat belt fastened correctly
Rin an almost upright position with their
back against the seat backrest
Rwith their feet resting on the floor, if possi-
ble
If the front passenger does not observe these
conditions, OCS may produce a false classi-
fication, e.g. because the front passenger:
Rtransfers their weight by supporting them-
selves on a vehicle armrest
Rsits in such a way that their weight is raised
from the seat cushion
If it is absolutely necessary to install a child
restraint system on the front-passenger seat,
be sure to observe the correct positioning of
the child restraint system. Never place
objects under or behind the child restraint
system, e.g. cushions. The entire base of the
child restraint system must always rest on the seat cushion of the front-passenger seat. The
backrest of the forward-facing child restraint
system must lie as flat as possible against the
backrest of the front-passenger seat.
The child restraint system must not touch theroof or be subjected to a load by the head
restraint. Adjust the angle of the seat back- rest and the head restraint position accord-
ingly.
Only then can OCS be guaranteed to function
correctly. Always observe the child restraint
system manufacturer's installation instruc-
tions.
Occupant Classification System opera-
tion (OCS)
PASSENGER AIR BAG OFF indicator lamp :
shows you whether the front-passenger front
air bag is deactivated.
XTurn the SmartKey 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 self-diagnostics.
The PASSENGER AIR BAG OFF indicator lamp
must light up for approximately six seconds.
The PASSENGER AIR BAG OFF indicator lamp
then displays the status of the front-
passenger front air bag. If the status of the
front-passenger front air bag changes while
the vehicle is in motion, an air bag display
message may appear in the instrument clus-
ter (
Ypage 198). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG OFF indicator lamp. Be
aware of the status of the front-passenger
front air bag both before and during the jour-
ney.
58Occupant safety
Safety
If the PASSENGER AIR BAG OFF indicator
lamp:
Ris lit: the front-passenger front air bag is
deactivated. It will then not be deployed in
the event of an accident.
Rdoes not light up: the front-passenger
front air bag is enabled. If, in the event of an accident, all deployment criteria are met,
the front-passenger front air bag is
deployed.
GWAR NING
If the PASS ENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is
disabled. It will notbe deplo yedinthe event of
an acc ident and cannot perform its intended
protective function. A person inthe front-
passenger seat could then, for example, come
into contact with the veh icle's interior, espe-
cial ly if the person issitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
When the front-passenger seat isoccupied,
always ensure that:
Rthe classification of the person inthe front-
passenger seat iscorrect and the front-
passenger front air bag isenabled or disa-
bled in accordance with the person inthe
front-passenger seat
Rthe front-passenger seat has been moved
back as far back as possible.
Rthe person isseated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag iscorrect.
GWAR NING
If you secure a ch ild ina childrestraint system
on the front-passenger seat and the
PASS ENGER AIR BAG OFF indicator lamp is
off, the front-passenger front air bag can
deplo yin the event of an acc ident. The ch ild
could bestruck bythe air bag. 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.
GWARNING
If you secure a child ina forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too close to the dashboard, the child could, inthe
event of an accident:
Rcome into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example
Rbe struck by the air bag if the PASSENGER
AIR BAG OFF indicator lamp isoff
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
belt sash guide to the shoulder belt guide on
the child restraint system. The shoulder belt
strap must be routed forwards and down-
wards from the vehicle belt sash guide. If nec- essary, adjust the vehicle belt sash guide and
the front-passenger seat accordingly. Always
observe the child restraint system manufac-
turer's installation instructions.
If OCS determines that:
Rthe front-passenger seat is unoccupied, the
PASSENGER AIR BAG OFF indicator lamp
lights up after the system self-test and
remains lit. This indicates that the front-
passenger front air bag is deactivated.
Rthe front-passenger seat is occupied by a
c
hild of up to twelve months old, in a stand-
ard child restraint system, the PASSENGER
AIR BAG OFF indicator lamp lights up after
the system self-test and remains lit. This
indicates that the front-passenger front air
bag is deactivated.
But even in the case of a twelve-month-old
child, in a standard child restraint system,
the PASSENGER AIR BAG OFF indicator
lamp can go out after the system self-test.
Occupant safety59
Safety
Z
When the front-passenger seat is occupied,
always ensure that:
Rthe classification of the person in the front-passenger seat is correct and the front-
passenger front air bag is enabled or disa-
bled in accordance with the person in the
front-passenger seat
Rthe person is seated properly with a cor-
rectly fastened seatbelt
Rthe front-passenger seat has been moved
back as far back as possible
If the PASSENGER AIR BAG OFF indicator
lamp remains lit when it should not, the front-
passenger seat may not be used. Do not
install a child restraint system on the front-
passenger seat. Have the Occupant Classifi-
cation System (OCS) checked and repaired
immediately at a qualified specialist work-
shop.
GWARNING
Objects between the seat surface and the
child restraint system could affect OCS oper- ation. This could result in the front-passenger
air bag not functioning as intended during an
accident. This poses an increased risk of
injury or even fatal injury.
Do not place any objects between the seat
surface and the child restraint system. The
entire base of the child restraint system must
always rest on the seat cushion of the front-
passenger seat. The backrest of the forward-
facing child restraint system must, as far as
possible, be resting on the backrest of the
front-passenger seat. Always comply with the
child restraint system manufacturer's instal-
lation instructions.
After the system self-test, the PASSENGER
AIR BAG OFF indicator lamp displays the sta-
tus of the front-passenger front air bag
(
Ypage 58).
For more information about the OCS, see
"Problems with the Occupant Classification
System" (
Ypage 62).
Occupant safety61
Safety
Z
Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Ypage 60).
ProblemPossible causes/consequences andMSolutions
The PASSENGER AIR
BAG OFF indicator
lamp lights up and
remains lit, even
though the front-
passenger seat is occu-
pied by an adult or a
person of a stature cor-
responding to that of an
adult.The classification of the person on the front-passenger seat is
incorrect.
XMake sure the conditions for a correct classification of the per-
son on the front-passenger seat are met (
Ypage 58).
XIf the PASSENGER AIR BAG OFF indicator lamp remains lit, the
front-passenger seat may not be used.
XHave OCS checked as soon as possible at an authorized
Mercedes-Benz Center.
The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or does not stay
on.
The front-passenger
seat is:
Runoccupied
Roccupied by the
weight of a child up
to 12 months old in a
child restraint sys-
tem
OCS is malfunctioning.
XMake sure there is nothing between the seat cushion and the
child seat.
XMake sure that the entire base of the child restraint system rests on the seat cushion of the front-passenger seat. The backrest of
the forward-facing child restraint system must lie as flat as pos-
sible against the backrest of the front-passenger seat. If nec-
essary, adjust the position of the front-passenger seat.
XWhen installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight using the front-
passenger seat adjustment. This could result in the seat belt and
the child restraint system being pulled too tightly.
XCheck for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to the
child restraint system. If necessary, adjust the head restraint
accordingly.
XMake sure that no objects are applying additional weight onto
the seat.
XIf the PASSENGER AIR BAG OFF indicator lamp remains off, do
not install a child restraint system on the front-passenger seat.
It is recommended that you install the child restraint system on
a suitable rear seat.
XHave OCS checked as soon as possible at an authorized
Mercedes-Benz Center.
62Occupant safety
Safety
Deployment of Emergency Tensioning
Devicesan dair bags
Important safet ynotes
GWARNING
The air bag parts are hot after an air bag has
bee ndeployed .There is aris kof injury.
Do no ttouch th eair bag parts .Hav e a
deployed air bag replaced at aqualified spe -
cialis tworkshop as soo nas possible.
GWARNING
A deployed air bag no longer offers any pro -
tection and canno tprovid eth eintended pro -
tection in an accident. There is an increase d
ris kof injury.
Hav eth evehicle towed to aqualified special-
ist workshop in order to hav e adeployed air
bag replaced.
It is important fo ryour safet yand that of your
passenger to hav edeployed air bags replaced
and to hav eany malfunctionin gair bags
repaired. Thi swill help to mak esur eth eair
bags continue to perform their protective
function fo rth evehicle occupant sin th e
event of acrash .
GWARNING
Pyrotechnic Emergency Tensioning Devices
that hav ebee ndeployed are no longer opera-
tional and are unable to perform their inten-
ded protective function .Thi sposes an
increase dris kof injury or eve nfatal injury.
Therefore, hav epyrotechni cEmergency Ten -
sioning Devices whic hhav ebee ntriggere d
immediately replaced at aqualified specialis t
workshop .
An electric moto ris used by PRE-SAF E®to
trigger th etightenin gof th eseat belt in haz -
ardous situations. Thi sprocedur eis reversi-
ble.
If Emergency Tensioning Devices are trig-
gered or air bags are deployed ,you will hear a
bang, and asmall amount of powder may also be released. The
6restrain tsystem warn -
in g lamp lights up.
Only in rar ecases will th eban gaffec tyour
hearing. The powder that is release dgener-
ally doe sno tconstitute ahealth hazard ,but it
may caus eshort-term breathin gdifficulties in
people wit hasthm aor other respirator yprob-
lems. To avoid this, you may wish to get out of
th evehicle or ope nth ewindows as soo nas it
is saf eto do so.
Ai rbags and pyrotechni cEmergency Tension-
in gDevices (ETDs) contain perchlorat emate-
rial ,whic hma
y require special handlin gand
regard fo rth eenvironment. National guide-
lines mus tbe observed durin gdisposal. In
California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm .
Method of operation
Duringth efirst stage of acollision ,th e
restrain tsystem contro luni tevaluates impor -
tant physical dat arelatin gto vehicle deceler -
ation or acceleration ,suc has:
Rduration
Rdirection
Rintensit y
Based on th eevaluation of this data, th e
restrain tsystem contro luni ttriggers th e
Emergency Tensioning Devices durin g afron -
ta lor rea rcollision .
An Emergency Tensioning Devic ecan only be
triggered, if:
Rth eignition is switched on
Rth ecomponent sof th erestrain tsystem are
operational; see "Restrain tsystem warnin g
lamp " (
Ypage 49)
Rthebelt tongue is engage din th ebuckl eon
th erespective front-passenger seat
The Emergency Tensioning Devices in th e
rea rcompartmen tare triggere dindepend -
entl yof th eloc kstatus of th eseat belts.
If th erestrain tsystem contro luni tdetects a
more severe accident, further component sof
Occupant safety63
Safety
Z
the restraint system are activated independ-
ently of each other in certain frontal collision
situations:
RFront air bags and driver's knee bag
RWindow 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 indi-
cator lamp is off. Observe the information on
the PASSENGER AIR BAG OFF indicator lamp
(
Ypage 49).
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 pro-
pellant gas if a second deployment threshold
is reached within a few milliseconds.
The activation threshold of the Emergency
Tensioning Devices and the air bag are deter-
mined by evaluating the rate of vehicle decel-
eration or acceleration which occurs at vari-
ous points in the vehicle. Th is p
rocess is pre-
emptive in nature. Deployment should take
place in good time at the start of the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
Rthe distribution of forces during the colli-
sion
Rthe collision angle
Rthe deformation characteristics of the vehi-
cle
Rthe 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
decisive role in the deployment of an air bag.
Nor do they provide an indication of air bag
deployment. The vehicle can be deformed considerably,
without an air bag being deployed. This is the
case if only parts which are relatively easily
deformed are affected and the rate of decel-
eration is not high. Conversely, air bags may
be deployed even though the vehicle suffers
only minor deformation. This is the case if, for
example, very rigid vehicle parts such as lon-
gitudinal body members are hit, and sufficientdeceleration occurs as a result.
If the restraint system contr ol u
nit detects a
side impact or if the vehicle rolls over, the
applicable components of the restraint sys-
tem are activated independently of each
other depending on the apparent type of acci-
dent.
RSide impact air bags and pelvis air bag on
the side of impact, 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 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
RWindow 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
REmergency Tensioning Device, if the sys-
tem determines that deployment can offer
additional protection in this situation
RWindow 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
iNot all air bags are deployed in an acci-
dent. The different air bag systems wo rk
i
ndependently of each other.
64Occupant safety
Safety
restraints, have this work carried out at a
qualified specialist workshop.
NECK-PRO luxury head restraints
Do not insert your finger between the cushion
of the head restraint and the cover. Pay par-
ticular attention while resetting the NECK-
PRO luxury head restraints.
XRemove resetting tool :from the vehicle
document wallet.
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 mech-
anism engage.
XPull out resetting tool :.
XWith your hand flat, firmly push the NECK-
PRO luxury head restraint cushion back-
wards in the direction of arrow =until it
engages.
XRepeat this procedure for the second
NECK-PRO luxury head restraint.
XPut resetting tool :back into the vehicle
document wallet.
iIf you have difficulty resetting the NECK-
PRO luxury head restraints, have this work
carried out at a qualified specialist work-
shop.
PRE-SAFE®(anticipatory occupant
protection system)
Introduction
In certain hazardous situations, PRE-SAFE®
takes pre-emptive measures to protect the
vehicle occupants.
Important safety notes
!Make sure that there are no objects in the
footwell or behind the seats. There is a dan-
ger that the seats and/or 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:
Rin emergency braking situations, e.g. when
BAS is activated
Rin critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely
Ron vehicles with the Driving Assistance
package: if BAS PLUS intervenes power-
fully or the radar sensor system detects an
imminent danger of collision in certain sit-
uations
PRE-SAFE
®takes the following measures
depending on the hazardous situation detec-
ted:
Rthe front seat belts are pre-tensioned.
Rthe front-passenger seat is adjusted if it is
in an unfavorable position.
Rif the vehicle skids, the sliding sunroof and
the side windows are closed so that only a
small gap remains. The panorama roof with
66Occupant safety
Safety
power tilt/sliding panel is completely
closed.
Rthe air pressure in the side bolsters of the
seat backrests of the front active multicon-
tour seats is raised.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE
®slackens
the belt pre-tensioning. On vehicles with
active 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:
XMove 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. You
will find information on the convenience func-
tion under "Belt adjustment" (
Ypage 53).
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 hazard-
ous situations, PRE-SAFE
®PLUS takes pre-
emptive measures to protect the vehicle
occupants.
Important safety notes
The intervention of PRE-SAFE®PLUS cannot
prevent an imminent collision.
The driver is not warned about the interven-
tion of PRE-SAFE
®PLUS.
PRE-SAFE
®PLUS does not intervene if the
vehicle is backing up. PRE-SAFE
®PLUS does not perform braking
actions while the vehicle is in motion or when
Parking Guidance is active.
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 meas-
ures depending on the hazardous situation
detected:
Rif the radar sensor system detects that a
head-on collision is imminent, the seat
belts are pre-tensioned.
Rif 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 vehi-
cle is stationary.
-the seat belts are pre-tensioned.
The PRE-SAFE
®PLUS braking application is
canceled:
Rif the accelerator pedal is depressed when
a gear is engaged
Rif the risk of a collision passes or is no lon-
ger detected
Rif DISTRONIC PLUS indicates an intention
to pull away
If the hazardous situation passes without
resulting 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:
Rthe hazard warning lamps are activated
Rthe emergency lighting is activated
Rthe vehicle doors are unlocked
Rthe front side windows are lowered
Occupant safety67
Safety
Z