
42 indicator lamp is
illuminated, indicating that the front-
passenger front air bag is deactivated.
Should the 42 indicator lamp
not illuminate or go out while the restraint
is installed, please check installation.
Periodically check the
42
indicator lamp while driving to make sure
the 42 indicator lamp is
illuminated.
If the 42 indicator
lamp goes out or remains out, do not
transport a child on the front-passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates.
R If you place a child in a forward-facing child
restraint on the front-passenger seat:
-move the seat as far back as possible
- use the proper child restraint
recommended for the age, size and
weight of the child
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
R For children larger than a typical 12-month-
old child, the front-passenger front air bag
can be activated or deactivated.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
also has to deploy.
The OCS may have detected that the seat:
R was empty or occupied by a person with a
weight of up to or less than that of a typical
12-month-old child seated in a standard
child restraint
R was occupied by a small individual, such as
a young teenager or a small adult
R was occupied by a child in a child restraint
system, whose weight is greater than that
of a typical 12-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.
If the SmartKey has been removed from the
ignition
lock or is in position 0, indicator lamp
42: does not light up. G
WARNING
If the red SRS 6 indicator lamp in the
instrument cluster and the 42
indicator lamp are lit at the same time, there
is a malfunction in the OCS. 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.52
Occupant safety
Safety

Belt warning for the driver and front
passenger
Regardless of whether the driver and front
passenger have fastened their seat belts
already, the
7 seat belt warning lamp
lights up for 6 seconds after every engine
start. It then goes out if the driver and the
front passenger have fastened their seat
belts.
If the driver's seat belt is not fastened after
the engine is started, an additional warning
tone will sound. The warning tone goes out
after approximately six seconds or once the
driver's seat belt is fastened.
If the driver or front passenger have not
fastened their seat belt after 6 seconds and
the doors are closed, the 7 seat belt
warning lamp lights up.
R until
the driver or the front passenger have
fastened their seat belts
R if a vehicle speed of 15 mph(25 km/h) is
exceeded once, a warning tone with
increasing intensity sounds additionally for
a maximum of 60 seconds or until the driver
or front passenger have fastened their seat
belts.
If the driver or front passenger undo their seat
belts during the journey, the 7 seat belt
warning lamp lights up and the warning tone
sounds again.
The warning tone ceases even if the driver or
front passenger have still not fastened their
seat belt after 60 seconds. The 7 seat belt
warning lamp stops flashing but continues to
be lit.
Once the vehicle is stationary, the warning
tone is reactivated and the 7 seat belt
warning lamp starts to flash again if the
vehicle speed exceeds 15 mph(25 km/h)
once.
The 7 seat belt warning lamp only goes
out if:
R both the driver and the front passenger
have fastened their seat belts. or
R
the
vehicle is stationary and a door is open.
i For more information on the 7 seat
belt warning lamp, see "Warning and
indicator lamps in the instrument cluster,
seat belt" ( Y page 420).
Emergency Tensioning Devices, belt
force limiters The front seat belts and the outer seat belts
in the rear are equipped with ETDs and seat
belt force limiters.
The
ETDs tighten the seat belts in an accident,
pulling them close against the body.
The ETDs do not correct incorrect seat
positions or incorrectly fastened seat belts.
The ETDs do not pull vehicle occupants back
towards the backrest.
Seat belt force limiters, when triggered, help
to reduce the peak force exerted by the seat
belt on the vehicle occupant.
The seat belt force limiters for the front seats
are synchronized with the front air bags.
These take on a part of the deceleration force.
Thus, the force exerted on the occupant is
distributed over a greater area.
The ETDs can only be activated when:
R the ignition is switched on.
R the restraint systems are operational; see
"SRS warning lamp" ( Y page 44).
R the belt tongue is engaged in the buckle on
each of the lap-shoulder belts in the front.
R the front-passenger seat is occupied and
the belt tongue is engaged in the buckle on
the front-passenger side.
The ETDs on the outside seats in the rear
compartment are triggered independently of
the lock status of the seat belts.
The ETDs are triggered depending on the type
and severity of an accident:
R if, in the event of a head-on or rear-end
collision, the vehicle decelerates or
accelerates rapidly in a longitudinal Occupant safety
61
Safety Z

R
ADAPTIVE BRAKE
R PRE-SAFE ®
Brake Important safety notes
G
WARNING
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. G
WARNING
HYBRID vehicles: It is imperative that you read
the HYBRID Supplemental Operating
Instructions
included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.
i Please note that the driving safety
systems described only work as effectively as possible when there is adequate contact
between
the tires and the road surface. Pay
particular attention to the information
regarding tires, recommended minimum
tire tread depths etc. in the "Wheels and
tires" section (Y page 490).
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 i
Observe the "Important safety notes"
section ( Y page 69).
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. G
WARNING
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 ! 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. Driving safety systems
69
Safety Z

The brakes will work normally again if:
R
you release the brake pedal.
R there
is no longer any danger of a rear-end
collision.
R no obstacle is detected in front of your
vehicle.
BAS PLUS is then deactivated.
For BAS PLUS to assist you when driving, the
radar sensor system must be switched on and
operational, see "Radar sensor system" in the
index. G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations. BAS
PLUS cannot intervene in these cases.
There is a risk of an accident. Always pay
careful
attention to the traffic situation and be
ready to brake.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of 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 G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R in curves
As a result, BAS PLUS cannot intervene in
critical situations. There is a risk of an
accident. Always pay careful attention to the
traffic situation and be ready to brake.
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.
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 i
See the "Important safety notes" section
(Y page 69).
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 ÷ ESP®
warning
lamp flashes in the instrument cluster. G
WARNING
Under no circumstances should you
deactivate ESP ®
when the ÷ ESP ®
warning lamp in the instrument cluster
flashes. Proceed as follows:
R when driving off, apply as little throttle as
possible.
R while driving, ease up on the accelerator
pedal.
R adapt
your speed to suit the prevailing road
and weather conditions.
Failure to observe these guidelines could
cause the vehicle to skid. ESP ®
cannot
prevent accidents resulting from excessive
speed.
! The ignition must be switched off if the
vehicle is being towed with the front or rear Driving safety systems
71
Safety Z

When you deactivate ESP
®
:
R ESP ®
no longer improves driving stability.
R the
engine's torque is no longer limited and
the drive wheels can spin. The spinning of
the wheels results in a cutting action, which
provides better grip.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
X To deactivate: (Y page 384).
The å ESP ®
OFF warning lamp in the
instrument cluster lights up. G
WARNING
When the å ESP®
OFF warning lamp is lit,
ESP ®
is deactivated.
If the ÷ ESP ®
warning lamp and the
å ESP ®
OFF warning lamp remain lit,
ESP ®
is not available due to a malfunction.
When ESP ®
is deactivated or not operational,
vehicle stability in standard driving
maneuvers is reduced.
Adapt your speed and driving to the prevailing
road conditions and to the non-operating
status of the ESP ®
.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain.
X To activate: (Y page 384).
The å ESP ®
OFF warning lamp in the
instrument cluster goes out. EBD (electronic brake force
distribution)
i Observe the "Important safety notes"
section ( Y page 69). EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking. G
WARNING
If EBD has malfunctioned, the braking system
remains available with full brake boosting
effect.
However, the rear wheels can still lock,
e.g. under full braking. This could cause you
to lose control of your vehicle and cause an
accident. You should therefore adapt your
driving style to the different handling
characteristics.
X Observe the notes on warning and indicator
lamps ( Y page 423) as well as display
messages ( Y page 392). ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In
addition to the braking function, ADAPTIVE
BRAKE also has the HOLD function
(Y page 342) and hill start assist
(Y page 306). For further information, see
Driving tips (Y page 327). PRE-SAFE
®
Brake
PRE-SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
i Observe the "Important safety notes"
section ( Y page 69).
PRE-SAFE ®
Brake can help you to minimize
the risk of a frontal collision with a vehicle
ahead or reduce the effects of such a
collision. If PRE-SAFE ®
Brake has detected a
risk of collision, you will be warned visually
and acoustically as well as by automatic
braking. PRE-SAFE ®
Brake cannot prevent a
collision without your intervention.
At speeds above approximately
4 mph (7 km/h), this function warns you
when you are rapidly approaching the vehicle
in front. An intermittent warning tone will Driving safety systems
73
Safety Z

then sound and the · distance warning
lamp in the instrument cluster will light up.
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.
If the driver and front passenger have their
seat belt fastened, PRE-SAFE ®
Brake can also
brake the vehicle automatically at speeds
from approximately 4 mph (7 km/h) to
approximately 124 mph (200 km/h).
Due to the nature of the system, particularly
complicated driving conditions may cause
unnecessary warnings or the unnecessary
intervention of PRE-SAFE ®
Brake. To stop the
braking action, you can either depress the
accelerator pedal further, activate kickdown
or release the brake pedal.
The braking action of PRE-SAFE ®
Brake is
ended automatically if:
R you maneuver to avoid the obstacle.
R there is no longer any danger of a rear-end
collision.
R there is no longer an obstacle detected in
front of your vehicle.
i USA only: this device 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.
Removing, altering or tampering with the
device will void any warranties, and is not
permitted by the FCC. Do not tamper with,
alter, or use in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
i Canada only: this device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and 2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted.
Do not tamper with, alter, or use
in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
With the help of the radar sensor system,
PRE-SAFE ®
Brake can detect obstacles that
are in front of your vehicle for an extended
period of time.
At speeds up to approximately 40 mph
(70 km/h), PRE-SAFE ®
Brake can also react
to stationary obstacles, for example stopped
or parked vehicles.
If you approach an obstacle and PRE-SAFE ®
Brake detects a risk of collision, the system
will initially alert you both visually and
acoustically. If you do not brake or take
evasive action, the system will warn you by
automatically braking the vehicle gently. If
there is an increased risk of collision,
preventative passenger protection measures
(PRE-SAFE ®
) are activated (Y page 55). If the
risk of collision remains at speeds of over
20 mph(30 km/h) and you do not brake, take
evasive action or accelerate significantly, the
vehicle may perform automatic braking up to
emergency braking. Automatic emergency
braking is not performed until immediately
prior to an accident that can no longer be
avoided. G
WARNING
Even if PRE-SAFE ®
Brake slows the vehicle
before an imminent rear-end collision, the
system cannot avert a collision without the
intervention
of the driver. There is a risk of an
accident. Brake according to the situation or
take evasive action. Delayed intervention by
the driver can lead to an accident. 74
Driving safety systems
Safety

G
WARNING
PRE-SAFE ®
Brake cannot always detect
complex traffic situations properly.
In these cases, PRE-SAFE(R) Brake may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
There is a risk of an accident. Always pay
particular
attention to the traffic situation and
be ready to brake, especially if PRE-SAFE(R)
Brake warns you. Terminate the intervention
in a non-critical driving situation.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of 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 G
WARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R in curves
As a result, PRE-SAFE ®
Brake cannot
intervene in critical situations. There is a risk
of an accident. Always pay careful attention
to the traffic situation and be ready to brake.
In
order to maintain the appropriate distance
to the vehicle in front and thus prevent a
collision, you must apply the brakes yourself. X
To activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer ( Y page 384).
After activation, the Ä symbol is
displayed on the left in the instrument
cluster.
For PRE-SAFE ®
Brake to assist you when
driving, the radar sensor system must be
switched on (Y page 387) and operational.
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. Theft deterrent locking systems
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
SmartKey that is left inside the vehicle.
X To activate with the SmartKey: remove
the SmartKey from the ignition lock.
X To activate with KEYLESS-GO:
switch the
ignition off and open the driver's door.
X To deactivate: switch on the ignition.
i The immobilizer is always deactivated
when you start the engine. ATA (Anti-Theft Alarm system)
A visual and audible alarm is triggered if the
alarm system is armed and you open:
R a door
R the vehicle with the mechanical key
R the trunk lid
R the hood Theft deterrent locking systems
75
Safety Z

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible.
Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops (Y page 31). Correct driver's seat position
Observe the safety guidelines on seat
adjustment (
Y page 103).
X Check whether you have adjusted seat =
properly.
Electrical seat adjustment ( Y page 104)
When adjusting the seat, make sure:
R you are as far away from the driver's air
bag as possible.
R you are sitting in a normal upright
position. R
you can fasten the seat belt properly.
R you have moved the backrest to an
almost vertical position.
R you have set the seat cushion angle so
that your thighs are gently supported.
R you can depress the pedals properly.
X Check whether the head restraint is
adjusted properly
(Y page 106).
When doing so, make sure that you have
adjusted the head restraint so that the back
of your head is supported at eye level by
the center of the head restraint.
Observe the safety guidelines on steering
wheel adjustment ( Y page 109).
X Check whether steering wheel : is
adjusted properly.
Adjusting the steering wheel electrically
(Y page 110)
When adjusting the steering wheel, make
sure:
R you
can hold the steering wheel with your
arms slightly bent.
R you can move your legs freely.
R you can see all the displays in the
instrument cluster clearly.
Observe the safety guidelines for seat belts
(Y page 57).
X Check whether you have fastened seat
belt ; properly
(Y page 59).
The seat belt should:
R fit snugly across your body
R be routed across the middle of your
shoulder
R be routed in your pelvic area across the
hip joints
X Before starting off, adjust the rear-view
mirror and the exterior mirrors
(Y page 111) in such a way that you have
a good view of road and traffic conditions.
X Vehicles with a memory function: save
the
seat, steering wheel and exterior mirror
settings ( Y page 113).102
Correct driver's seat position
Seats, steering wheel and mirrors