
PRE-SAFE®
(preventative occupant
protection)
i AMG vehicles do not include the PRE-
SAFE ®
system.GWARNING
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 preemptive measures to
protect occupants in certain hazardous
situations.
PRE-SAFE ®
intervenes:
R if BAS intervenes, e.g. in emergency
braking situations
R if BAS PLUS intervenes powerfully on
vehicles with DISTRONIC PLUS
R if, on vehicles with DISTRONIC PLUS, the
radar sensor system detects an imminent
danger of collision in certain situations
R in critical driving situations, e.g. when
physical limits are exceeded and the
vehicle understeers or oversteers severely
PRE-SAFE ®
takes the following measures
depending on the hazardous situation
detected:
R the seat belts are pre-tensioned.
R on vehicles with memory function for the
front-passenger seat: the front-passenger
seat is adjusted if it is in an unfavorable
position.
R if the vehicle skids, 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. All settings made by
PRE-SAFE ®
can then be reversed.
If the seat belts are not released:XMove the backrest or seat back slightly, but
only when the vehicle is stationary.
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 seat-belt
adjustment, a convenience function
integrated into PRE-SAFE ®
, can be found in
the "Seat-belt adjustment" section
( Y page 51).
NECK-PRO head restraints
The NECK-PRO head restraints increase
protection to the driver's and front
passenger's head and neck. To this end, the
NECK-PRO head restraints on the driver's and
front-passenger seats are moved forwards
and upwards in the event of a rear-end
collision of a certain severity. 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
Seat or head restraint covers can cause a
malfunction when the NECK-PRO head
restraints are activated or when the side
impact air bags are deployed, or they can
prevent this completely. The NECK-PRO head
restraints or side impact air bags can
Occupant safety47SafetyZ

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 ! warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Brakes
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
XIf ABS intervenes: continue to depress the
brake pedal vigorously until the braking
situation is over.XTo make a full brake application:
depress the brake pedal with full force.
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving.
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.
BAS (Brake Assist System)
i Observe the "Important safety notes"
section ( Y page 56).
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 System Plus)
BAS PLUS is only available in vehicles
equipped with DISTRONIC PLUS.
i Observe the "Important safety notes"
section ( Y page 56).
BAS PLUS assists you when braking in a
hazardous situation at speeds of over
20 mph (30 km/h), and uses the radar sensor
system to assess traffic conditions.
i This device has been approved by the FCC
as a "Vehicular Radar System". The radar
sensor 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.
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.
BAS PLUS can also react to stationary
obstacles, e.g. stopped or parked vehicles, at
speeds of up to approximately 40 mph
(70 km/h).
Should you approach an obstacle and BAS
PLUS has detected a risk of collision, BAS
PLUS calculates the braking force necessary
to avoid a rear-end collision. Should you apply
the brakes forcefully, BAS PLUS can
Driving safety systems57SafetyZ

automatically increase the braking force to a
level suitable for the traffic conditions.
If BAS PLUS demands particularly high
braking force, preventative passenger
protection measures (PRE-SAFE ®
) are
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 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.
GWARNING
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
GWARNING
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 56).
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.
58Driving safety systemsSafety

braking. PRE-SAFE®
Brake cannot prevent a
collision without your intervention.
At speeds above approximately
20 mph (30 km/h), this function warns you
when you are rapidly approaching the vehicle
in front. An intermittent warning tone will
then sound and the · distance warning
lamp in the instrument cluster will light up.XBrake immediately in order to increase the
distance from the vehicle in front.
or
XTake evasive action provided it is safe to do
so.
At speeds of above approximately
20 mph (30 km/h), if the driver and front
passenger have fastened their seat belts,
PRE-SAFE ®
Brake can:
R brake the vehicle automatically at speeds
up to approximately 124 mph (200 km/h)
R trigger preventative occupant protection
measures (PRE-SAFE ®
) ( Y page 47)
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 your speed drops below approximately
9 mph (15 km/h).
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 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 47). If the
risk of collision remains and you do not brake,
take evasive action or accelerate
significantly, the vehicle may perform
automatic emergency braking. Automatic
emergency braking is not performed until
immediately prior to an accident that can no
longer be avoided.Driving safety systems63SafetyZ

GWARNING
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.
GWARNING
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
GWARNING
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.XTo activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer ( Y page 190).
The Ä symbol appears in the
multifunction display as long as the HOLD
function is not activated ( Y page 168).
On vehicles with Parking Guidance, the
Ä symbol is displayed when P is
engaged or is selected or if you drive faster
than 22 mph (35 km/h).
For PRE-SAFE ®
Brake to assist you when
driving, the radar sensor system must be
switched on ( Y page 194) and be
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 system
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.
XTo activate with the SmartKey: remove
the SmartKey from the ignition lock.XTo activate with KEYLESS-GO: switch the
ignition off and open the driver's door.XTo deactivate: switch on the ignition.
i
The immobilizer is always deactivated
when you start the engine.
In the event that the engine cannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Contact an authorized Mercedes-Benz
64Theft deterrent locking systemSafety

:& Locks the vehicle;F Unlocks the trunk lid=% Unlocks the vehicle
When unlocking, the turn signals flash once.
When locking, they flash three times.
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer ( Y page 193).
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated using
the on-board computer ( Y page 194).
XTo unlock centrally: press the %
button.
If you do not open the vehicle within
approximately 40 seconds of unlocking:
R the vehicle is locked again.
R the theft deterrent locking system is armed
again.
XTo lock centrally: press the & button.
KEYLESS-GO
Important notes on the use of KEYLESS-
GO
R Do not keep the KEYLESS-GO key together
with:
- electronic devices, e.g. a mobile phone
or another key
- metallic objects, e.g. coins or metal foil.
This can affect the functionality of
KEYLESS-GO.
R Bear in mind that the engine can be started
by any of the vehicle occupants if there is
a KEYLESS-GO key in the vehicle.
Locking and unlocking centrally
You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry
the SmartKey with you. You can combine the
KEYLESS-GO functions with those of a
conventional key, e.g. using KEYLESS-GO to
unlock and pressing the & button to lock.
When locking and unlocking using KEYLESS-
GO, the distance between the SmartKey and
the corresponding door handle must not
exceed 3 ft (1 m).
KEYLESS-GO checks whether a valid key is in
the vehicle by periodically establishing a radio
connection between the vehicle and the key.
This happens:
R when the external door handles are
touched
R when starting the engine
R while the vehicle is in motion
X To unlock the vehicle: touch the inner
surface of the door handle.XTo lock the vehicle: touch sensor
surface :.XConvenience closing feature: touch
recessed sensor surface ; for an
extended period ( Y page 81).SmartKey69Opening/closingZ

If you pull on the handle of the trunk lid, only
the trunk of the vehicle is unlocked.
Changing the settings of the locking
system
You can change the settings of the locking
system so that when unlocking, only the
driver's door, the lockable stowage
compartments in the vehicle interior and the
fuel filler flap are unlocked. This is useful if
you frequently travel on your own.
XTo change the setting: press and hold
down the % and & buttons
simultaneously for approximately
six seconds until the battery check lamp
flashes twice ( Y page 71).
i
If the setting of the locking system is
changed within the signal range of the
vehicle, pressing the & or % button
locks or unlocks the vehicle.
The SmartKey now functions as follows:
XTo unlock the driver's door: press the
% button once.XTo unlock centrally: press the %
button twice.XTo lock centrally: press the & button.
The KEYLESS-GO function is changed as
follows:
XTo unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.XTo unlock centrally: touch the inner
surface of the front-passenger door handle.XTo lock centrally: touch the outer sensor
surface on one of the door handles.
Restoring the factory settings
XPress the % and & buttons
simultaneously for approximately
six seconds until the battery check lamp
flashes twice.Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey, use the
mechanical key.
If you use the mechanical key to unlock and
open the driver's door or the trunk lid, the
anti-theft alarm system will be triggered
( Y page 65).
There are several ways to turn off the alarm:
XTo turn the alarm off with the
SmartKey: press the % or & button
on the SmartKey.
or
XInsert the SmartKey into the ignition lock.
or
XTo deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the
ignition lock. The SmartKey must be in the
vehicle.
or
XLock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the
vehicle.
If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked
automatically.
XTo unlock the fuel filler flap: insert the
SmartKey in the ignition lock.
Removing the mechanical key
70SmartKeyOpening/closing

XTo open all side windows: press
switch : as far as the point of resistance.XTo open all side windows fully: press
switch : beyond the point of resistance.
i
If, after opening the windows, you then
close a side window using the switch on the
door control panel, the rear side windows
will remain open. To close the rear side
windows, you must pull the switch on the
center console and hold it in position. All of
the side windows will then close one after
the other.
XTo close all side windows: pull
switch :.
The rear side windows close after the front
side windows.XMake sure that all the side windows are
fully closed.
i When the roof is open, only the two front
side windows can be operated using the
switch on the center console.
With the SmartKey
GWARNING
Make sure that nobody can become trapped
as you close the side windows.
Proceed as follows if there is a risk of
entrapment:
R release the & button.
R press and hold the % button until the
side windows open again.
When the roof is closed and the trunk
partition is open, the SmartKey can be used
to open or close all side windows
simultaneously:XMake sure that the roof is closed
( Y page 84) and that the trunk partition
is open ( Y page 85).XPoint the tip of the SmartKey at the driver's
door handle.XTo open all side windows: press and hold
the % button on the SmartKey until the
side windows are fully open.XTo interrupt the opening procedure:
release the % button.XTo close all side windows: press and hold
the & button on the SmartKey until the
side windows are fully closed.XTo interrupt the closing procedure:
release the & button.
Convenience closing with KEYLESS-GO
GWARNING
When using the convenience closing feature,
make sure that nobody can become trapped.
Proceed as follows if there is a risk of
entrapment:
R release the sensor surface on the door
handle.
R pull the door handle immediately and hold
it.
The side windows open.
The KEYLESS-GO SmartKey must be outside
the vehicle. All the doors must be closed.
Side windows81Opening/closingZ