2015 MERCEDES-BENZ S-Class Pre safe function

the child restraint system. Never place
objects under or behind the child restraint
system, e.g. cushions. 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 forwards-facing child restraint
system must, as far as possible, be resting on the backrest of the front-passenger seat.
The child restraint system must not touch the
roof or be put under strain 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
; PASSENGER AIR BAG ON indicator lamp
The indicator lamps inform you whether the
front-passenger front air bag is deactivated or
enabled.
X Press 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 simultaneously for approx-
imately six second s. The indi
cator lamps display the status of the
front-passenger front air bag.
R PASSENGER AIR BAG OFF :lights up: the
front-passenger front air bag is deactiva-
ted. It will then not be deployed in the event
of an accident.
R PASSENGER AIR BAG ON ;lights 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.
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 instru-
ment cluster (Y page 332). When the front-
passenger seat is occupied, always pay atten-
tion to the PASSENGER AIR BAG ON and
PASSENGER AIR BAG OFF indicator lamps. Be aware of the status of the front-passenger
front air bag both before and during the jour- ney. G
WARNING
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:
R the 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
R the front-passenger seat has been moved
back as far back as possible.
R the 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. 60
Occupant safetySafety

Deployment of Emergency Tensioning
Devices and air bags
Important safety notes G
WARNING
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. G
WARNING
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 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
Pyrotechnic Emergency Tensioning Devices
that have been deployed 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.
Therefore, have pyrotechnic Emergency Ten-
sioning Devices which have been triggered
immediately replaced at a qualified specialist workshop.
An electric motor is used by PRE-SAFE ®
to
trigger the tightening of the seat belt in haz-
ardous situations. This procedure is reversi-
ble.
If Emergency Tensioning Devices are trig-
gered or air bags are deployed, you will hear a bang, and a small amount of powder may also be released. The
6restraint system warn-
ing lamp lights up.
Only in rare cases will the bang affect your
hearing. The powder that is released gener-
ally does not constitute a health hazard, but it may cause short-term breathing difficulties in
people with asthma or other respiratory prob-
lems. To avoid this, you may wish to get out of
the vehicle or open the windows as soon as it is safe to do so.
Air bags and pyrotechnic Emergency Tension-
ing Devices (ETDs) contain perchlorate mate-
rial, which may require special handling and
regard for the environment. National guide-
lines 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 impor-
tant physical data relating to vehicle deceler-
ation or acceleration, such as:
R duration
R direction
R intensity
Based on the evaluation of this data, the
restraint system control unit triggers the
Emergency Tensioning Devices during a fron-
tal 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; see "Restraint system warning lamp" (Y page 50)
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 independ-
ently of the lock status of the seat belts. Occupant safety
65Safety Z

The side impact air bag on the front-
passenger side (front) deploys in the fol-
lowing situations:
- 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 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 acci-
dent. The different air bag systems work
independently of each other.
How the air bag system works is deter-
mined by the severity of the accident detec- ted, especially the vehicle deceleration or
acceleration and the apparent type of acci-dent:
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
vehicle occupants.
Important safety notes !
Make sure that there are no objects in the
footwell under or behind the seats when
moving the seats back. There is a risk that
the seats and/or the objects could be dam-
aged. Despite your vehicle being equipped with the
PRE-SAFE ®
system, the possibility of per-
sonal injuries occurring as a result of an acci- dent cannot be eliminated. Always adapt your
driving style to suit the prevailing road and
weather conditions and maintain a safe dis-
tance from the vehicle in front. Drive care-
fully.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely
R vehicles with the Driving Assistance pack-
age: when a driver assistance system inter-
venes powerfully or the radar sensor sys-
tem detects an imminent danger of colli-
sion in certain situations
PRE-SAFE ®
takes the following measures
depending on the hazardous situation detec-
ted:
R the front seat belts are pre-tensioned.
R if the vehicle skids, the panorama roof with
power tilt/sliding panel and the side win-
dows are closed so that only a small gap
remains.
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
pressure 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
resulting in an accident, PRE-SAFE ®
slackens
the belt pre-tensioning. On vehicles with mul-
ticontour seats, the air pressure in the side Occupant safety
67Safety Z

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. Infor-
mation about the convenience function can
be found under "Belt adjustment"
(Y page 55). 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 when PRE-SAFE ®
PLUS intervenes.
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:
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 vehi-
cle is stationary.
- the seat belts are pre-tensioned.
The PRE-SAFE ®
PLUS braking application is
canceled:
R if the accelerator pedal is depressed when
a gear is engaged
R if the risk of a collision passes or is no lon-
ger detected
R if 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:
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 the electrically adjustable steering wheel is
raised
R the engine is switched off and the fuel sup-
ply is cut off
R vehicles with seat belt extenders: the seat-
belt buckles for the outer rear seats are
illuminated and extend forwards 68
Occupant safetySafety

When the override feature is activated, the
controls in the rear compartment are disabled
for:
R the rear side windows
R adjustment of the front-passenger seat
from the rear compartment
R the sunblinds:
- of the rear side windows
- of the rear window
- in the roof Pets in the vehicle
G
WARNING
If you leave animals unattended or unsecured in the vehicle, they could press buttons or
switches, for example.
As a result, they could:
R activate vehicle equipment and become
trapped, for example
R activate or deactivate systems, thereby
endangering other road users
Unsecured animals could also be flung around
the vehicle in the event of an accident or sud- den steering or braking, thereby injuring vehi-
cle occupants. There is a risk of an accident
and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals properly during
the journey, e.g. use a suitable animal trans-
port box. Driving safety systems
Overview of driving safety systems
In this section, you will find information about the following driving safety systems:
R ABS (Anti-lock BrakingSystem)
(Y page 76)
R BAS ( Brake Assist System) (Y page 77)
R BAS PLUS (Brake AssistSystem PLUS) with
Cross-Traffic Assist (Y page 77)R
COLLISION PREVENTION ASSIST PLUS
(distance warning function and Adaptive
Brake Assist) (Y page 79)
R ESP ®
(Electronic StabilityProgram)
(Y page 81)
R EBD ( Electronic Brake force Distribution)
(Y page 83)
R ADAPTIVE BRAKE (Y page 84)
R PRE-SAFE ®
Brake (Y page 84)
R STEER CONTROL (Y page 86) Important safety notes
If you fail to adapt your driving style or if you
are inattentive, the driving safety systems can
neither reduce the risk of an accident nor
override the laws of physics. Driving safety
systems are merely aids designed to assist
driving. You are responsible for maintaining
the distance to the vehicle in front, for vehicle
speed, for braking in good time and for stay-
ing in lane. Always adapt your driving style to
suit the prevailing road and weather condi-
tions and maintain a safe distance from the
vehicle in front. Drive carefully.
The driving safety systems described only
work as effectively as possible when there is
adequate contact between the tires and the
road surface. Please pay special attention to
the notes on tires, recommended minimum
tire tread depths, etc. (Y page 442).
In wintry driving conditions, always use winter
tires (M+S tires) and if necessary, snow
chains. Only in this way will the driving safety systems described in this section work as
effectively as possible. ABS (Anti-lock Braking System)
General information ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi-
cle when braking. 76
Driving safety systemsSafety

The
! ABS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out when the engine is running.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 76). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid- ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information on the ABS warning lamp (Y page 358) and
display messages which may be shown in the
instrument cluster (Y page 317).
ABS works from a speed of about 5 mph
(8 km/h) , regardless of road-surface condi-
tions. ABS works on slippery surfaces, even
when you only brake gently.
Braking X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit- uation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel a pulsing in the brake pedal.
The pulsating brake pedal can be an indica-
tion of hazardous road conditions, and func-
tions as a reminder to take extra care while
driving. BAS (Brake Assist System)
General information BAS operates in emergency braking situa-
tions. If you depress the brake pedal quickly,
BAS automatically boosts the braking force,
thus shortening the stopping distance.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 76). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. BAS PLUS (Brake Assist System
PLUS) with Cross-Traffic Assist
General information i
Observe the "Important safety notes" sec-
tion (Y page 76).
BAS PLUS is only available on vehicles with
the Driving Assistance package.
For BAS PLUS to assist you when driving, the radar sensor system and the camera system
must be operational.
With the help of a sensor system and a cam-
era system, BAS PLUS can detect obstacles:
R that are in the path of your vehicle for an
extended period of time
R that cross the path of your vehicle Driving safety systems
77Safety Z

Function
To avoid a collision, BAS PLUS calculates the
brake force necessary if:
R you approach an obstacle, and
R BAS PLUS has detected a risk of collision
When driving at a speed under 20 mph
(30 km/h) : if you depress the brake pedal,
BAS PLUS is activated. The increase in brake pressure will be carried out at the last possi-
ble moment.
When driving at a speed above 20 mph
(30 km/h) : if you depress the brake pedal
sharply, BAS PLUS automatically raises the
brake pressure to a value adapted to the traf-
fic situation.
BAS PLUS provides braking assistance in haz- ardous situations with vehicles in front within
a speed range between 4 mph (7 km/h) and
155 mph (250 km/h).
At speeds of up to approximately 44 mph
(70 km/ h), BAS PLUS can react to:
R stationary objects in the path of your vehi-
cle, e.g. stopped or parked vehicles
R pedestrians in the path of your vehicle
R objects crossing your path and that are
recognized in the detection range of the
sensors
i If BAS PLUS demands particularly high
braking force, preventative passenger pro-
tection measures (PRE-SAFE ®
) are activa-
ted simultaneously.
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
BAS PLUS is deactivated and the brakes func-
tion as usual again, if:
R you release the brake pedal.
R there is no longer a risk of collision.
R no obstacle is detected in front of your
vehicle.
R you depress the accelerator pedal.
R you activate kickdown. COLLISION PREVENTION ASSIST
PLUS
General information COLLISION PREVENTION ASSIST PLUS con-
sists of a distance warning function with an
autonomous braking function and adaptive
Brake Assist.
COLLISION PREVENTION ASSIST PLUS can
help you to minimize the risk of a front-end
collision with a vehicle ahead or reduce the
effects of such a collision.
If COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a collision, you
will be warned visually and acoustically. If you do not react to the visual and audible collision
warning, autonomous braking can be initiated in critical situations. If you apply the brake
yourself in a critical situation, the COLLISION PREVENTION ASSIST PLUS adaptive Brake
Assist assists you.
Important safety notes In particular, the detection of obstacles can
be impaired if:
R there is dirt on the sensors or anything else
covering the sensors
R there is snow or heavy rain
R there is interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
R new vehicles or after a service on the COL-
LISION PREVENTION ASSIST PLUS system
Observe the notes in the section on break-
ing-in (Y page 188).
Following damage to the front end of the vehi- cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at low speeds where there is no visible
damage to the front of the vehicle. Driving safety systems
79Safety Z

Distance warning function
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 76).G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and do not rely solely on the distance
warning function.
Function X To activate/deactivate: activate or deac-
tivate the distance warning function in the
on-board computer (Y page 309).
If the distance warning function is not activa-
ted, the æsymbol appears in the assis-
tance graphics display.
The distance warning function can help you to minimize the risk of a front-end collision with
a vehicle ahead or reduce the effects of such
a collision. If the distance warning function
detects that there is a risk of a collision, you
will be warned visually and acoustically. Starting at a speed of around 4 mph (7 km/h),
the distance warning function warns you if
you rapidly approach a vehicle in front. An
intermittent warning tone will then sound,
and the ·distance warning lamp will light
up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action, provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause the system to display a
warning.
With the help of the radar sensor system, the
distance warning function can detect obsta-
cles that are in the path of your vehicle for an extended period of time.
Up to a speed of around 44 mph (70 km/h),
the distance warning function can also react
to stationary obstacles, such as stopped or
parked vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision,
the system will initially alert you both visually
and acoustically.
Autonomous braking function If the driver does not react to the distance
warning signal in a critical situation, COLLI-
SION PREVENTION ASSIST PLUS can assist
with the autonomous braking function.
The autonomous braking function:
R gives the driver more time to react to criti-
cal driving situations
R can help the driver to avoid an accident or
R reduces the effects of an accident
The autonomous braking function is available in the following speed ranges:
R from 5 mph (7 km/h) to approx. 65 mph
(105 km/ h)for moving objects
R from 5 mph (7 km/h) to approx. 31 mph
(50 km/h) for stationary objects 80
Driving safety systemsSafety