MERCEDES-BENZ GLC SUV 2017 X253 Workshop Manual

passenger front air bag is deactivated
(Ypage 44).
RAlways observe the instructions and safety
notes on the "Occupant Classification System
(OCS)" (
Ypage 51) and on "Children in the
vehicle" (Ypage 59) in addition to the child
restraint system manufacturer's installation
and operating instructions.
Objects in the vehicle interior may prevent
an air bag from functioning correctly. Before
starting your journey and to avoid risks resulting from the speed of the air bag as it deploys, make
sure that:
Rthere are no people, animals or objects
between the vehicle occupants and an air
bag.
Rthere are no objects between the seat, door
and B-pillar.
Rno hard objects, e.g. coat hangers, hang on
the grab handles or coat hooks.
Rno accessories, such as cup holders, are
attached to the vehicle within the deployment
area of an air bag, e.g. to doors, side windows,
rear side trim or side walls.
Rno heavy, sharp-edged or fragile objects are in
the pockets of your clothing. Store such
objects in a suitable place.
GWARNING
If you modify the air bag cover or affix objects
such as stickers to it, the air bag can no longer
function correctly. There is an increased risk
of injury.
Never modify an air bag cover or affix objects
to it.
GWARNING
Sensors to control the air bags are located in
the doors. Modifications or work not per-
formed correctly to the doors or door panel-
ing, as well as damaged doors, can lead to the
function of the sensors being impaired. The air
bags might therefore not function properly
anymore. Consequently, the air bags cannot
protect vehicle occupants as they are
designed to do. There is an increased risk of
injury.
Never modify the doors or parts of the doors.
Always have work on the doors or door pan-
eling carried out at a qualified specialist work-
shop.
Front air bags
!Do not place heavy objects on the front-
passenger seat. This could cause the system
to identify the seat as being occupied. In the
event of an accident, the restraint systems on
the front-passenger side may be triggered
and have to be replaced.
Driver's air bag :deploys in front of the steer-
ing wheel. Front-passenger front air bag ;
deploys in front of and above the glove box.
When deployed, the front air bags offer addi-
tional head and thorax protection for the occu-
pants in the front seats.
The PASSENGER AIR BAG OFF indicator lamp
informs you about the status of the front-
passenger front air bag (
Ypage 44).
The front-passenger front air bag will only
deploy if:
Rthe system, based on the OCS weight sensor
readings, detects that the front-passenger
seat is occupied (
Ypage 51). The
PASSENGER AIR BAG OFF indicator lamp is
not lit (
Ypage 51)
Rthe restraint system control unit predicts a
high accident severity
Occupant safety49
Safety
Z

Driver's kneeba g
Driver' sknee bag :deploys under th esteerin g
column .The driver's knee bag is triggere d
together wit hth efron tair bag.
The driver's knee bag offers additional thigh ,
knee and lowe rleg protection fo rth eoccupant
in th edriver's seat .
Sideimpact air bags
GWARNING
Unsuitable seat cover scan obstruct or pre -
ven tdeploymen tof th eair bags integrated
into th eseats. Consequently, th eair bags
canno tprotect vehicle occupant sas they are
designed to do. In addition ,th eoperation of
th eoccupant classification syste m(OCS )
could be adversely affected. Thi sposes an
increase dris kof injury or eve nfatal injury.
You should only use seat cover sthat hav e
bee napproved fo rth erespective seat by
Mercedes-Benz.
Fron tsid eimpact air bags :and rea rsid e
impact air bags ;deploy next to th eouter bol-
ster of th eseat backrest . Whe
ndeployed ,th esid eimpact air bag offers
additional thorax protection .However, it doe s
no tprotect the:
Rhead
Rneck
Rarm s
In th eevent of asid eimpact ,th esid eimpact air
bag is deployed on th esid eon whic hth eimpact
occurs.
The sid eimpact air bag on th efront-passenger
sid edeploys under th efollowin gconditions:
Rth eOCS system detects that th efront-
passenger seat is occupied or
Rth eseat belt buckl etongue is engage din th e
belt buckl eof th efront-passenger seat
If th ebelt tongue is engage din th ebelt buckle,
th esid eimpact air bag on th efront-passenger
sid edeploys if an appropriat eacciden tsituation
occurs. In this case, deploymen tis independen t
of whether th efront-passenger seat is occupied
or not.
Window curtain air bags
Window curtain air bags :are integrated into
th esid eof th eroof frame and deployed in th e
are afrom th eA-pilla rto th eC-pillar .
Whe ndeployed ,th ewindow curtain air bag
enhance sth elevel of protection fo rth ehead .
However, it doe sno tprotect th echest or arms.
In th eevent of asid eimpact ,th ewindow curtain
air bag is deployed on th esid eon whic hth e
impact occurs.
If th esyste mdetermines that they can offe r
additional protection to that provided by th e
seat belt , awindow curtain air bag may be
deployed in other acciden tsituation s
(
Ypage 55) .
50Occupant safety
Safety

Occupant Classification System
(OCS)
Introduction
The Occupant Classification System (OCS) cat-
egorizes 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 window curtain air bag
Rthe Emergency Tensioning Devices
Requirements
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 possible
If the front passenger does not observe these
conditions, OCS may produce a false classifica-
tion, 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. a
cushion. Fully retract the seat cushion length.
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 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.
Only then can OCS be guaranteed to function
correctly. Always observe the child restraint sys-
tem manufacturer's installation and operating
instructions.
Occupant Classification System opera-
tion (OCS)
:PASSENGER AIR BAG ON indicator lamp
;PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front air bag is deactivated or
enabled.
XPress the Start/Stop button once or twice, or
turn the SmartKey to position 1or 2in the
ignition lock.
The system carries out self-diagnostics.
The PASSENGER AIR BAG OFF and PASSENGER AIR BAG ON indicator lamps must light up simul-
taneously for approximately six seconds.
The indicator lamps display the status of the
front-passenger front air bag.
RPASSENGER AIR BAG ON lights up for 60 sec-
onds, subsequently both indicator lamps are
off (PASSENGER AIR BAG ON and OFF): the
front-passenger front air bag is able to deploy
in the event of an accident.
RPASSENGER AIR BAG OFF lights up: the front-
passenger front air bag is deactivated. It will
then not be deployed in the event of an acci-
dent.
If the PASSENGER AIR BAG ON indicator lamp is
off, only the PASSENGER AIR BAG OFF indicator lamp shows the status of the front-passenger
front air bag. The PASSENGER AIR BAG OFF
indicator lamp may be lit continuously or be off.
If the status of the front-passenger front air bag
changes while the vehicle is in motion, an air bag
display message appears in the instrument clus-
ter (
Ypage 237). 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 journey.
Occupant safety51
Safety
Z

GWARNING
If the PASSENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is
disabled. It will not be deployed in the event of
an accident and cannot perform its intended
protective 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.
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 front-passenger seat has been moved
back as far back as possible.
Rthe person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag is correct.
GWARNING
If you secure a child in a rearward-facing child
restraint system on the front-passenger seat
and the PASSENGER AIR BAG OFF indicator
lamp is off, the front-passenger front air bag
may deploy in the event of an accident. The
child could be struck by the 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.
If the PASSENGER AIR BAG OFF indicator lamp
stays off, do not install a rearward-facing child
restraint system on the front-passenger seat.
You can find more information on OCS under
"Problems with the Occupant Classification Sys-
tem" (
Ypage 54).
GWARNING
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:
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 is off
This poses an increased risk of injury or even fatal injury.
Always move the front-passenger seat as far
back as possible and fully retract the seat
cushion length. 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 downwards from the vehicle belt sash
guide. If necessary, adjust the vehicle belt
sash guide and the front-passenger seat
accordingly. Always observe the child
restraint system manufacturer'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
child of up to twelve months old, in a standard
child restraint system, the PASSENGER AIR
BAG OFF indicator lamp lights up after the
system self-test and remains lit. This indi-
cates 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. This indi-
cates that the front-passenger front air bag is
activated. The result of the classification is
dependent on, among other factors, the child restraint system and the child's stature. It is
52Occupant safety
Safety

recommended that you install the child
restraint system on a suitable rear seat.
Rthe front-passenger seat is occupied by a per-
son of smaller stature (e.g. a teenager or
small adult), the PASSENGER AIR BAG OFF
indicator lamp lights up and remains lit after
the system self-test depending on the result
of the classification or, alternatively, goes out.
-If the PASSENGER AIR BAG OFF indicator
lamp is off, move the front-passenger seat
as far back as possible. Alternatively, a per-
son of smaller stature can sit on a rear seat.
-If the PASSENGER AIR BAG OFF indicator
lamp is lit, a person of smaller stature
should not use the front-passenger seat.
Rthe front-passenger seat is occupied by an
adult or a person of adult stature, the
PASSENGER AIR BAG OFF indicator lamp
goes out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated.
If children are traveling in the vehicle, be sure to
observe the notes on "Children in the vehicle"
(
Ypage 59).
When the occupant classification system (OCS)
is malfunctioning, the red 6restraint system
warning lamp in the instrument cluster and the
PASSENGER AIR BAG OFF indicator lamp light
up simultaneously. The front-passenger front air bag is deactivated in this case and does not
deploy during an accident. Have the Occupant
Classification System (OCS) checked and
repaired immediately at a qualified specialist
workshop. Mercedes-Benz recommends that
you use an authorized Mercedes-Benz Center
for this purpose.
If the front-passenger seat, the seat cover or the
seat cushion are damaged, have the necessary
repair work carried out at a qualified specialist
workshop. Mercedes-Benz recommends that
you use an authorized Mercedes-Benz Center
for this purpose.
For safety reasons, Mercedes-Benz recom-
mends that you only use seat accessories that
have been approved by Mercedes-Benz.
If the driver's air bag deploy
s, this does not
mean that the front-passenger front air bag will
also deploy. The Occupant Classification Sys-
tem (OCS) categorizes the occupant in the front-
passenger seat. Depending on that result, the
front-passenger front air bag is either enabled or
deactivated.
System self-test
GDANGER
If both the PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps do
not light up during the system self-test, the
system is malfunctioning. The front-
passenger front air bag might be triggered
unintentionally or might not be triggered at all
in the event of an accident with high deceler-
ation. This poses an increased risk of injury or
even fatal injury.
In this case the front-passenger seat may not
be used. Do not install a child restraint system
on the front-passenger seat. Have the Occu-
pant Classification System (OCS) checked
and repaired immediately at a qualified spe-
cialist workshop.
GWARNING
If the PASSENGER AIR BAG OFF indicator
lamp remains lit after the system self-test, the
front-passenger front air bag is disabled. It will
not be deployed in the event of an accident. In
this case, the front-passenger front air bag
cannot perform its intended protective func-
tion, e.g. when a person is seated in the front-
passenger seat.
That person could, for example, come into
contact with the vehicle's interior, especially
if the person is sitting too close to the dash-
board. This poses an increased risk of injury or
even fatal injury.
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
as far back as possible
If the PASSENGER AIR BAG OFF indicator
lamp remains lit when it should not, the front-
Occupant safety53
Safety
Z

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 or PASSENGER AIR BAG ON indicator
lamp displays the status of the front-passenger
front air bag (
Ypage 51). If the front-passenger
front air bag is enabled, the PASSENGER AIR
BAG ON indicator lamp lights up for 60 seconds
and then goes out.
If the PASSENGER AIR BAG ON indicator lamp is
off, only the PASSENGER AIR BAG OFF indicator lamp shows the status of the front-passenger
front air bag. The PASSENGER AIR BAG OFF
indicator lamp may be lit continuously or be off.
For more information about the OCS, see "Prob-
lems with the Occupant Classification System"
(
Ypage 54).
Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Ypage 53).
54Occupant safety
Safety

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 per-
son of a stature corre-
sponding to that of an
adult.The classification of the person on the front-passenger seat is incor-
rect.
XMake sure the conditions for a correct classification of the person
on the front-passenger seat are met (Ypage 51).
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 with the
weight of a child up to
twelve months old in a
child restraint system
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 possible
against the backrest of the front-passenger seat. If necessary,
adjust the position of the front-passenger seat.
XMake sure that the seat cushion length is fully retracted.
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 accord-
ingly.
XMake sure that no objects are applying additional weight onto the
seat.
XIf the PASSENGER AIR BAG OFF indicator lamp remains off and/or
the PASSENGER AIR BAG ON indicator lamp lights up, do not install a child restraint system on the front-passenger seat. It is recom-
mended 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.
Deployment of Emergency Tensioning
Devices and air bags
Important safety notes
GWARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible.
GWARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified special-
ist workshop in order to have a deployed air
bag replaced.
It is important for your safety and that of your
passenger to have deployed air bags replaced
Occupant safety55
Safety
Z

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.
GWARNING
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 6restraint 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:
Rduration
Rdirection
Rintensity
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:
Rthe ignition is switched on
Rthe components of the restraint system are
operational. You can find further information
under: "Restraint system warning lamp"
(
Ypage 44)
Rthe seat belt buckle tongue has engaged in
the belt buckle of the respective front seat
The Emergency Tensioning Devices in the rear
compartment are triggered independently of the
lock status of the seat belts.
If the restraint system control unit detects a
more severe accident, further components of
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 t
he
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 (
Ypage 44).
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.
The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by:
Rthe distribution of forces during the collision
Rthe collision angle
Rthe deformation characteristics of the vehicle
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 deci-
56Occupant safety
Safety

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.
RSide 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 seat belt buckle 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
RFront Emergency Tensioning Devices, if the
system determines that deployment can offer
additional protection for the vehicle occu-
pants in this situation
RRear Emergency Tensioning Devices in cer-
tain situations if the vehicle rolls over
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 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:
RFrontal collision
RSide impact
RRollover
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:
Rin emergency braking situations, e.g. when
BAS is activated
Rin critical driving situations, e.g. when physi-
cal limits are exceeded and the vehicle under-
steers or oversteers severely
Rvehicles 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- uations
Occupant safety57
Safety
Z

PRE-SAFE®takes the following measures
depending on the hazardous situation detected:
Rthe front seat belts are pre-tensioned.
Rif the vehicle skids, the side windows and the
panorama roof with power tilt/sliding panel
are closed.
Rvehicles with the memory function for the
front-passenger seat: the front-passenger
seat is adjusted if it is in an unfavorable posi-
tion.
If the hazardous situation passes without result-
ing in an accident, PRE-SAFE
®slackens the belt
pre-tensioning. 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. Informa-
tion about the convenience function can be
found under "Belt adjustment" (
Ypage 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 about the intervention
of PRE-SAFE
®PLUS.
PRE-SAFE®PLUS does not intervene:
Rif the vehicle is backing up
Rwhen 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:
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 vehicle is sta-
tionary.
-the seat belts are pre-tensioned.
The PRE-SAFE®PLUS braking application is can-
celed:
Rif the accelerator pedal is depressed when a
gear is engaged
Rif the risk of a collision passes or is no longer
detected
Rif 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:
Rthe hazard warning lamps are activated
Rthe emergency lighting is activated
Rthe vehicle doors are unlocked
Rthe front side windows are lowered
Rvehicles with a memory function: the electri-
cally adjustable steering wheel is raised
Rthe engine is switched off and the fuel supply
is cut off
Rvehicles with mbrace: automatic emergency
call
58Occupant safety
Safety