Occupant Classification System
(OCS)
Method of operation G
WARNING
If the 45 indicator lamp illuminates
when an adult or someone larger than a small
individual is in the front passenger seat, have
the front passenger reposition himself or
herself in the seat until the 45
indicator lamp goes out.
In the event of a collision, the air bag control
unit will not allow front passenger front air bag
deployment when the OCS has classified the
front passenger seat occupant as weighing as
much as or less than a typical 12-month-old
child in a standard child restraint or if the front
passenger seat is classified as being empty.
When the OCS senses that the front
passenger seat occupant is classified as
being up to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 45indicator lamp will
illuminate when the engine is started and
remain illuminated. This indicates that the
front passenger front air bag is deactivated.
When the OCS senses that the front
passenger seat is classified as being empty,
the 45 indicator lamp will illuminate
when the engine is started and remain
illuminated. This indicates that the front
passenger front air bag is deactivated.
When the OCS senses that the front
passenger seat occupant is classified as
being heavier than the weight of a typical 12-
month-old child seated in a standard child
restraint or as being a small individual (such
as a young teenager or a small adult), the
45 indicator lamp will illuminate for
approximately 6 seconds when the engine is
started. Depending on occupant weight
sensor readings from the seat, it will then
remain illuminated or go out. With the
45 indicator lamp illuminated, the
front passenger front air bag is deactivated. With the
45 indicator lamp out, the
front passenger front air bag is activated.
When the OCS senses that the front
passenger seat occupant is classified as an
adult or someone larger than a small
individual, the 45indicator lamp will
illuminate for approximately six seconds
when the engine is started and then go out.
This indicates that the front passenger front
air bag is activated.
If the 45 indicator lamp is illuminated,
the front passenger front air bag is
deactivated and will not be deployed.
If the 45 indicator lamp is not
illuminated, the front passenger front air bag
is activated and will be deployed
R in the event of certain frontal impacts
R if the impact exceeds a predetermined
triggering threshold
R independent of the side impact air bag or
pelvis air bag
If the front passenger front air bag is
deployed, the rate of inflation will be
influenced by
R the rate of vehicle deceleration as assessed
by the air bag control unit
R the front passenger's weight category as
identified by the OCS G
WARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seats whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriate infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
The infant or child restraint must be properly
secured with the vehicle's seat belt, the seat
belt and Top Tether strap, or lower anchors Occupant safety
49Safety
Z
If the key is removed from the ignition lock or
is in position 0, PASSENGER AIRBAG OFF
indicator lamp :does not light up.
The Occupant Classification System (OCS)
categorizes the occupant on the front-
passenger seat using a weight sensor. The
front-passenger front air bag is deactivated
automatically for certain weight categories.
PASSENGER AIRBAG OFF indicator lamp :
shows you the current status. If PASSENGER
AIRBAG OFF indicator lamp :is lit, the front-
passenger front air bag is disabled.
The system does not deactivate:
R the side impact air bag
R the window curtain air bag
R the ETDs
To be classified correctly, the front passenger
must sit:
R with the seat belt fastened correctly
R in a position that is as upright as possible
with their back against the seat backrest
R with their feet on the floor
The OCS weight sensor reading is affected if
the occupant's weight is transferred, e.g. by
leaning on the armrest.
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.
For safety reasons, Mercedes-Benz
recommends that you only use seat
accessories that have been approved by
Mercedes-Benz. Both the driver and the front passenger
should always observe the PASSENGER AIR
BAG OFF indicator lamp as an indication of
whether or not the front passenger is
positioned correctly. Observe also the air bag
display messages that can be displayed in the
instrument cluster (Y page 301).
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
will also deploy.
The OCS may have detected that the seat:
R is empty or occupied by the weight of a
typical child up to twelve months old,
seated in a child restraint system.
R is occupied by a small individual, such as a
young teenager or a small adult.
R is occupied by a child in a child restraint
system whose weight is greater than that
of a typical twelve month old child.
These are examples of when the OCS
deactivates the front-passenger front air bag.
Deactivation takes place although the
collision fulfills the criteria for deploying the
driver's air bag.
System self-test G
WARNING
If the 45indicator lamp does not
illuminate, the system is not functioning. You
must contact an authorized Mercedes-Benz
Center before seating any child on the front
passenger seat. G
WARNING
Objects between the seat surface and the
child restraint system could affect the
function of the OCS. This could result in the
front-passenger front 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. Make
sure that the bottom and back of the child
restraint system make full contact with the
front-passenger seat cushion and backrest. Occupant safety
51Safety
Z
Problem Possible causes/consequences and
M
MSolutions The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or stays on.
The front-passenger
seat is:
R unoccupied
R occupied with the
weight of a child up
to twelve months old
in a child restraint
system The OCS is malfunctioning.
X
Make sure there is nothing between the seat cushion and the
child seat.
X Make sure that the backrest and base of the child restraint
system are resting securely on the front-passenger seat. If
necessary, adjust the position of the front-passenger seat.
X When installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight with the front-
passenger seat adjustment. This could result in the seat belt
being pulled too tightly.
X Check the installation of the child restraint system.
X Make sure that no objects are applying additional weight onto
the seat.
X If the PASSENGER AIR BAG OFF indicator lamp remains off, have
the OCS system checked as soon as possible at a qualified
specialist workshop. Do not transport a child on the front-
passenger seat until the OCS has been repaired.
X Observe the additional display messages in the multifunction
display (Y page 301). PRE-SAFE
®
(anticipatory occupant
protection system)
Introduction PRE-SAFE
®
takes preemptive measures to
protect occupants in certain hazardous
situations.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats when resetting
the seats. There is a risk that the seats
and/or the objects could be damaged.
Despite your vehicle being equipped with the
PRE-SAFE ®
system, the possibility of
personal injuries occurring as a result of an
accident cannot be eliminated.
Always adapt your driving style to suit the
prevailing road and weather conditions and
maintain a safe distance from the vehicle in
front. Drive carefully. Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated.
R in critical driving situations, e.g. when
physical limits are exceeded and the
vehicle understeers or oversteers severely.
R on vehicles with DISTRONIC PLUS: if
BAS PLUS brakes hard 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 sliding sunroof and
the side windows are closed so that only a
small gap remains. On vehicles with a
panorama roof with power tilt/sliding
panel, they are closed completely. 54
Occupant safetySafety
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving.
Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 258).
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The
digging-in effect achieved in the process
reduces the stopping distance on off-road
terrain. This limits steering capability. BAS (Brake Assist System)
General information BAS operates in emergency braking
situations. 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"
section (Y page 67). 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)
General information i
Observe the "Important safety notes"
section (Y page 67).
BAS PLUS is only available in vehicles
equipped with DISTRONIC PLUS.
For BAS PLUS to assist you, the radar sensor
system must be operational.
With the help of the radar sensor system, BAS
PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time.
If the radar sensor system is malfunctioning,
BAS PLUS will not be available. The brake
system is still available with complete brake
boosting effect and BAS.
BAS PLUS can help you to minimize the risk
of a collision with a vehicle or reduce the
effects of such a collision. If BAS PLUS
detects a danger of collision, you are assisted
when braking.
Important safety notes G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering 68
Driving safety systemsSafety
As a result, BAS PLUS may not intervene in all
critical situations. There is a risk of an
accident.
Always pay careful attention to the traffic
situation and be ready to brake.
In the event of snowfall or heavy rain, the
recognition can be impaired.
Recognition by the radar sensor system is
also impaired in the event of:
R dirt on the sensors or anything else
covering the sensors
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
relative to the center of your vehicle
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
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
possible 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
traffic situation.
BAS PLUS provides braking assistance in
hazardous 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 40 mph
(70 km/h), BAS PLUS can also react to
stationary objects. Examples of stationary
objects are stopped or parked vehicles.
i
If BAS PLUS demands particularly high
braking force, preventative passenger
protection measures (PRE-SAFE ®
) are
activated 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
function 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.
If you have activated DSR (Y page 256), BAS
PLUS is likewise deactivated. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
Adaptive Brake Assist and the distance
warning function, which are described in the
following.
Distance warning function
Important safety notes
i
Observe the "Important safety notes"
section ( Ypage 67). 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 Driving safety systems
69Safety
Z
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
situation 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
situation and do not rely solely on the distance
warning function.
Function
X To activate/deactivate: activate or
deactivate the distance warning function in
the on-board computer (Y page 281).
If the distance warning function is not
activated, the æsymbol appears in the
assistance 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. The distance warning function
cannot prevent a collision without your
intervention.
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
conditions may also cause the system to
display a warning.
With the help of the radar sensor system, the
distance warning function can detect
obstacles that are in the path of your vehicle
for an extended period of time.
From a speed of around 40 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.
In particular, the detection of obstacles can
be impaired if:
R 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
relative to the center of your vehicle
R new vehicles or after the COLLISION
PREVENTION ASSIST system has been
serviced
Observe the notes in the section on
breaking-in (Y page 166).
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle. 70
Driving safety systemsSafety
Adaptive Brake Assist
i
Observe the "Important safety notes"
section (Y page 67). G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic
situations.
In such cases, Adaptive Brake Assist may:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving
conditions may also cause Brake Assist to
intervene.
Adaptive Brake Assist aids you in braking
during hazardous situations at speeds above
4 mph (7 km/h) and uses the radar sensor
system to evaluate the traffic situation.
With the help of Adaptive Brake Assist, the
distance warning signal can detect obstacles
that are in the path of your vehicle for an
extended period of time.
Should you approach an obstacle and
Adaptive Brake Assist has detected a risk of
collision, Adaptive Brake Assist calculates the braking force necessary to avoid a rear-end
collision. Should you apply the brakes
vigorously, Adaptive Brake Assist will
automatically increase the braking force to a
level suitable for the traffic conditions.
X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal.
R there is no longer any danger of a collision.
R no obstacle is detected in front of your
vehicle.
Adaptive Brake Assist is then deactivated.
Vehicles with PRE-SAFE ®
:if adaptive Brake
Assist requires particularly high brake
pressure, preventive passenger protection
measures (PRE-SAFE ®
) are deployed
simultaneously.
Up to vehicle speeds of around 155 mph
(250 km/h), adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles.
If Adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
R 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 Driving safety systems
71Safety Z
R
a vehicle traveling in front on a different line
relative to the center of your vehicle
R new vehicles or after the COLLISION
PREVENTION ASSIST system has been
serviced
Observe the notes in the section on
breaking-in (Y page 166).
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section (Y page 67).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tires and
the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilize the vehicle during braking.
4ETS (Electronic Traction System) 4ETS traction control is part of ESP
®
.
Traction control brakes the drive wheels
individually if they spin. This enables you to
pull away and accelerate on slippery surfaces,
for example if the road surface is slippery on
one side. In addition, more drive torque is
transferred to the wheel or wheels with
traction.
Traction control remains active, even if you
deactivate ESP ®
.
In appropriate driving situations, activate the
off-road program (Y page 258). Off-road 4ETS (Electronic Traction
System) A 4ETS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y
page 258).
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further
driving safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! Only operate the vehicle for a maximum
of ten seconds on a brake test
dynamometer. Switch off the ignition.
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
! A function or performance test should
only be carried out on a two-axle
dynamometer. Before you operate the
vehicle on such a dynamometer, please
consult a qualified workshop. You could
otherwise damage the drive train or the
brake system.
ESP ®
is deactivated if the åwarning lamp
in the instrument cluster lights up
continuously when the engine is running.
If the ÷ warning lamp and the å
warning lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 329) and display messages which
may be shown in the instrument cluster
(Y page 291).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly. 72
Driving safety systemsSafety