
If the SmartKey has been removed from the
ignition lock or is in position 0, indicator lamp
45 : does not light up.GWarning
If the red 6 SRS warning lamp in the
instrument cluster and the 45
indicator lamp light up simultaneously, the
OCS is malfunctioning. The front passenger
front air bag will be deactivated in this case.
Have the system checked by qualified
technicians as soon as possible. Contact an
authorized Mercedes-Benz Center.
Only have the seat repaired or replaced at an
authorized Mercedes-Benz Center.
In order to ensure proper operation of the air
bag system and OCS:
R Sit with the seat belt properly fastened in a
position that is as upright as possible with
your back against the seat backrest.
R When seated, a passenger should not
position him/herself in such a way as to
cause the passenger's weight to be lifted
from the seat cushion as this may result in
the OCS being unable to correctly
approximate the passenger's weight
category.
R Read and observe all warnings in this
chapter.
System self-test
The 45 indicator lamp illuminates
when you:
R turn the SmartKey to position 1 or 2 in the
ignition lock
R on vehicles with KEYLESS-GO, press the
Start/Stop button once or twice
If an adult is seated properly on the passenger
seat and the OCS classifies the occupant as
an adult, the 45 indicator lamp
illuminates and goes out again after
approximately 6 seconds.
If the seat is not occupied and the OCS
classifies the front passenger seat as being
unoccupied, the 45 indicator lamp
will illuminate and not go out.GWarning!
If the 4 5 indicator 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.
For more information, see "Problems with the
Occupant Classification System"
( Y page 47).
GWarning
Never place anything between seat cushion
and child seat (e.g. a pillow), since it reduces
the effectiveness of the OCS. The underside
and rear side child restraint system must be
placed entirely on the seat cushion and the
backrest of the front-passenger seat
backrest.
If necessary, adjust the tilt of the passenger
seat backrest.
An incorrectly mounted child seat could cause
injuries to the child in case of an accident,
instead of increasing protection for the child.
Follow the manufacturer's instructions for
installation of child restraint systems.
46Occupant safetySafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 46

Problems with the occupant classification systemProblemPossible causes/consequences and M SolutionsThe 45
indicator lamp
illuminates and
remains illuminated.
The person sitting on
the front-passenger
seat:
R weighs as much as a
typical adult
R weighs more than a
childOCS is malfunctioning.XHave OCS checked as soon as possible at an authorized
Mercedes-Benz Center.XObserve the additional display messages in the multifunction
display ( Y page 239).GWarning
If the 45 indicator lamp illuminates and remains illuminated when the weight of a typical
adult or someone larger than a small individual has been detected on the passenger seat, do not
allow any occupant to use the passenger seat until the system has been repaired.
ProblemPossible causes/consequences and M SolutionsThe 45
indicator lamp does not
illuminate and/or does
not remain illuminated.
The front-passenger
seat is:
R unoccupied
R occupied with the
weight of a typical
12-month-old child in
a standard child
restraint or lessOCS is malfunctioning.XMake sure there is nothing between the seat cushion and the
child seat.XCheck the installation of the child restraint system.XMake sure there are no objects applying additional weight onto
the seat.XIf the 45 indicator lamp remains out, have OCS checked
as soon as possible at an authorized Mercedes-Benz Center. Do
not transport a child on the front-passenger seat until OCS has
been repaired.XObserve the additional display messages in the multifunction
display ( Y page 239).GWarning
If the 45 indicator lamp does not illuminate or remains out with the weight of a typical
12-month-old child in a standard child restraint or less, or is unoccupied, on the front-passenger
seat, do not transport a child on the front-passenger seat until the system has been repaired.
Occupant safety47SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 47Z

System self-test
The 45 indicator lamp illuminates
when you:
R turn the SmartKey to position 1 or 2 in the
ignition lock
R on vehicles with KEYLESS-GO, press the
Start-Stop button once or twice
The 45 indicator lamp goes out again
after approximately six seconds.
If the 45 indicator lamp does not
illuminate or is lit continuously, the system is
malfunctioning. Before transporting a child
on the front-passenger seat, have the
BabySmart™ system checked at an
authorized Mercedes-Benz Center.
For more information, see "Problems with the
air bag deactivation system" section
( Y page 51)
GWarning
Do not place powered-on laptops, mobile
phones, electronic tags such as those used in
ski passes or similar electronic devices on the
front passenger seat. Signals from such
devices may interfere with the BabySmart™
air bag deactivation system. Such signal
interference may cause the 45
indicator lamp not to come on during self-test.
The 6 SRS indicator lamp and/or the
45 indicator lamp could be
continuously lit, indicating that the system is
not functioning. The front-passenger front air
bag could deploy inadvertently or fail to
deploy in an accident.
50Occupant safetySafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 50

Problems with the air bag deactivation systemProblemPossible causes/consequences and M SolutionsThe 45
indicator lamp
illuminates and
remains illuminated.A special BabySmart™ compatible child restraint system is
installed on the front-passenger seat.
The front-passenger front air bag is therefore deactivated.A BabySmart™-compatible child restraint system is not installed
on the front-passenger seat. The BabySmart™ system is
malfunctioning.XHave the BabySmart™ system checked as soon as possible at
an authorized Mercedes-Benz Center.GWarning
If the 45 indicator lamp illuminates and remains illuminated when the weight of a typical
adult or someone larger than a small individual has been detected on the passenger seat, do not
allow any occupant to use the passenger seat until the system has been repaired.
ProblemPossible causes/consequences and M SolutionsThe 45
indicator lamp does not
illuminate or does not
remain illuminated with
a BabySmart™-
compatible child
restraint system
properly installed on
the front-passenger
seat.The BabySmart™ system is malfunctioning.XMake sure there is nothing between the seat cushion and the
child seat.XCheck the installation of the child restraint system.XIf the 45 indicator lamp does not illuminate, have the
BabySmart™ system checked as soon as possible at an
authorized Mercedes-Benz Center.
Do not transport a child on the front-passenger seat until the
child seat recognition system has been repaired.PRE-SAFE ®
systemGWarning
The PRE-SAFE ®
system reduces the impact of
an accident on vehicle occupants, as long as
their seat belts have been fastened correctly.
Although your vehicle is equipped with a PRE-
SAFE ®
system, the possibility of injury in the
event of an accident cannot be ruled out. You
should therefore always drive carefully and
adapt your driving style to the prevailing road,
weather and traffic conditions.
PRE-SAFE ®
takes pre-emptive measures to
protect the occupants in certain hazardous
situations.
PRE-SAFE ®
intervenes:
R in emergency braking situations, e.g. if BAS
is activated or, on vehicles with DISTRONIC
PLUS, if BAS PLUS or PRE-SAFE ®
Brake
intervenes powerfully
R if the radar sensor system detects an
imminent danger of collision in certainOccupant safety51SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 51Z

situations (on vehicles with DISTRONIC
PLUS)
R in critical driving situations, e.g. when
physical limits are exceeded and the
vehicle understeers or oversteers severely
or when having to swerve to avoid an
obstacle at a speed above 85 mph
(140 km/h).
PRE-SAFE ®
takes the following measures
depending on the hazardous situation
detected:
R the front seat belts are pre-tensioned.
R under accident conditions, the front-
passenger seat is adjusted if it is in an
unfavorable position.
R increases the air pressure in the side
bolsters of the seat cushion and seat
backrest of the active multicontour seats in
the front.
R if the vehicle skids, the sliding roof with
power tilt/sliding panel and the side
windows are closed so that only a small gap
remains.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pretensioning. The air pressure in the
side bolsters on the active multicontour seat
is reduced again. All settings made by PRE-
SAFE ®
can then be reversed.
If the seat belts are not released:XWhen the vehicle is stationary, move the
backrest or seat back slightly.
The belt pretensioning is reduced and the
locking mechanism is released.GWarning
Make sure that nobody can become trapped
as you adjust the seat.
! 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.
More information about belt adjustment, a
convenience function integrated into PRE-
SAFE ®
, can be found in the "Belt adjustment"
section ( Y page 56).
NECK-PRO head restraints
The NECK-PRO head restraints increase
protection for the driver's and front-
passenger's head and neck. In the event of a
rear collision of a certain severity, the NECK-
PRO head restraints on the driver's and front-
passenger seats are moved forwards and
upwards. This provides better head support.
GWarning
Do not secure any objects (e.g. coat hangers)
on the NECK-PRO head restraints. Otherwise,
the NECK-PRO head restraints may not
function properly, or in the event of a rear-end
collision may not be able offer the level of
protection they are designed to provide.
GWarning
Only use seat covers/head restraint covers
that have been tested and approved by
Mercedes-Benz for your model.
Using seat covers and head restraint covers
other than those recommended may cause a
malfunction when NECK-PRO head restraints
are triggered or front side impact air bags/
pelvis air bags may be prevented from
deploying.
Contact an authorized Mercedes-Benz Center
for availability.
If the NECK-PRO head restraints have been
triggered in an accident, you must reset the
NECK-PRO head restraints on the driver's and
front-passenger seat ( Y page 53).
Otherwise, the additional protection will not
be available in the event of another rear-end
collision. You can recognize that NECK-PRO
head restraints have been triggered by the
fact that they have moved forwards and can
no longer be adjusted.
52Occupant safetySafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 52

This device complies with the RSS-210
regulations of Industry Canada. Operation
is subject to the following two conditions:
1. This device may not cause interference,
and
2. This device must withstand any
interference received, including
interference that may cause undesired
operation of the device.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
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 Braking System)
R BAS ( Brake Assist System)
R BAS PLUS ( Brake Assist System Plus*)
R ESP ®
(E lectronic Stability Program)
R EBD ( Electronic Brake-power Distribution)
R ADAPTIVE BRAKE
R PRE-SAFE ®
Brake (vehicles with
DISTRONIC PLUS)
Important safety notes
GWarning
The following factors increase the risk of
accidents:
R Excessive speed, especially in turns
R Wet and slippery road surfaces
R Following another vehicle too closely
The driving safety systems described in this
section cannot reduce these risks or prevent
the natural laws of physics from acting on the
vehicle. They cannot increase braking or
steering efficiency beyond that afforded by
the condition of the vehicle brakes and tires
or the traction afforded.
Only a safe, attentive, and skillful driver can
prevent accidents.
The capabilities of a vehicle equipped with the
driving safety systems described in this
section must never be exploited in a reckless
or dangerous manner which could jeopardize
the user's safety or the safety of others.
Always adjust your driving style to the
prevailing road and weather conditions and
keep a safe distance to other road users and
objects on the street.
If a driving system malfunctions, other driving
safety systems may also switch off. Observe
indicator and warning lamps that may come
on as well as messages in the multifunction
display that may appear.
i 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)
Important safety notes
GWarning
Observe "Important safety notes"
( Y page 65).
GWarning
Do not pump the brake pedal. Use firm, steady
brake pedal pressure instead. Pumping the
brake pedal defeats the purpose of the ABS
and significantly reduces braking
effectiveness.
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
ABS works from a speed of about
5 mph (8 km/h) upwards, regardless of road-
surface conditions. ABS works on slippery
surfaces, even when you only brake gently.
Driving safety systems65SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 65Z

The ! warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
XIf ABS intervenes: continue to depress the
brake pedal with force until the braking
situation is over.XTo make a full brake application:
depress the brake pedal with full force.GWarning
If the ABS malfunctions, other driving systems
such as the BAS or the ESP ®
are also switched
off. Observe indicator and warning lamps that
may come on as well as messages in the
multifunction display that may appear.
If the ABS malfunctions, the wheels may lock
during hard braking, reducing the steering
capability and extending the braking distance.
The pulsating brake pedal can be an
indication of hazardous road conditions and
functions as a reminder to take extra care
while driving.
BAS (Brake Assist)
GWarning
Observe "Important safety notes"
( Y page 65).
BAS operates in emergency braking
situations. If you depress the brake pedal
quickly, BAS automatically boosts the braking
force, thus shortening the stopping distance.
XKeep 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.
GWarning
If the BAS malfunctions, the brake system still
functions, but without the additional brake
boost available that the BAS would normally
provide in an emergency braking maneuver.
Therefore, the braking distance may increase.
BAS PLUS (Brake Assist PLUS)
GWarning
Observe "Important safety notes"
( Y page 65).
At speeds above approximately
20 mph (30 km/h), BAS PLUS assists you
when braking in hazardous situations and
uses the radar sensor system to evaluate the
traffic conditions.
GWarning!
BAS PLUS is a convenience system designed
to assist the driver during vehicle operation.
The responsibility for the vehicle speed and
the distance to the vehicle ahead, including
most importantly brake operation to assure
safe stopping distance, always remains with
the driver.
Always pay attention to traffic conditions
even while BAS PLUS is switched on.
Otherwise, you may not be able to recognize
dangerous situations until it is too late and
could cause an accident. Personal or fatal
injury to you or others may be the result.
i This equipment has been approved by the
FCC as a "Vehicular Radar System". The
radar sensor system is intended for use in
an automotive radar system only. Removal,
tampering, or altering of the device will void
any warranties, and is not permitted by the
FCC. Do not tamper with the device in any
way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
66Driving safety systemsSafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 66

BAS PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time. Should you approach a detected
obstacle quickly, BAS PLUS calculates the
braking force necessary to avoid a rear-end
collision. Should you additionally apply the
brakes, BAS PLUS will automatically increase
the braking force to a level suitable for the
traffic conditions.
If BAS PLUS demands particularly high
braking force, PRE-SAFE ®
is activated
simultaneously.XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again when:
R you release the brake pedal
R no obstacle is detected in front of your
vehicle
R there is no longer any danger of a rear-end
collision
BAS PLUS is then deactivated.
At speeds up to approximately
40 mph (70 km/h), BAS PLUS can also detect
stationary obstacles, for example, stopped or
parked vehicles.
For BAS PLUS to assist you when driving, the
radar sensor system must be switched on and
operational. You can check this by activating
DISTRONIC PLUS ( Y page 179) or via the
"radar sensor" function in the on-board
computer( Y page 232).
GWarning!
BAS PLUS will only respond with brake
assistance if it has clearly detected an object.
Detection can be impeded by
R dirty or covered sensors
R snowfall or heavy rain
R disturbance from other radar sources
R strong radar reflection such as in parking
garages
BAS PLUS uses radar signals that are not
reflected well by narrow objects and
absorptive materials. For this reason BAS
PLUS will not react to persons, animals, and
approaching traffic or cross-traffic.
BAS PLUS may not detect narrow vehicles
driving in front of you, such as motorcycles
and vehicles driving offset from your vehicle
center.
Following a collision or accident-related
damage to the front end of the vehicle, have
the configuration and operation of the radar
sensors checked at an authorized Mercedes-
Benz Center.
If BAS PLUS is not available due to a
malfunction in the radar sensor system, the
brake system remains available with full
brake boosting effect and BAS.
ESP ®
(Electronic Stability Program)
Important safety notes
GWarning
Observe "Important safety notes"
( Y page 65).
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. If necessary, 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.
If ESP ®
intervenes, the ä warning lamp
flashes in the instrument cluster.
Driving safety systems67SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 67Z