
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R 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 vehicleGWARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, PRE-SAFE ®
Brake may neither
give warnings nor 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 order to maintain an appropriate distance
from 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 348).
After activation, the Ä symbol is
displayed on the left in the instrument
cluster.
For BAS PLUS to assist you, the radar sensor
system must 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
Center or call 1-800-FOR-MERCedes (in
USA) or 1-800-387-0100 (in Canada).
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
The alarm is not switched off, even if you
close the open door that has triggered it, for
example.
70Theft deterrent locking systemSafety

iIf the alarm stays on for more than
30 seconds, the mbrace (USA only) or TELE
AID (Canada only) emergency call system
initiates a call to the Customer Assistance
Center automatically. The emergency call
system initiates the call provided that:
R you have subscribed to the mbrace/
TELE AID service.
R the mbrace/TELE AID service has been
activated properly.
R the required mobile phone, power supply
and GPS are available.XTo arm: lock the vehicle with the SmartKey
or KEYLESS-GO.
Indicator lamp : flashes. The alarm
system is armed after approximately
30 seconds.XTo disarm: unlock the vehicle with the
SmartKey or KEYLESS-GO.XTo stop the alarm using the SmartKey:
insert the SmartKey into the ignition lock.
The alarm is switched off.
or
XPress the % or & button on the
SmartKey.
The alarm is switched off.XTo stop the alarm using KEYLESS-GO:
grasp the outside door handle. The
SmartKey must be outside the vehicle.
The alarm is switched off.
or
XPress the Start/Stop button on the
dashboard. The SmartKey must be inside
the vehicle.
The alarm is switched off.Theft deterrent locking system71SafetyZ

Vehicle equipment
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-
relevant systems and functions.
SmartKey
Important safety notes
GWARNING
When leaving the vehicle, always remove the
SmartKey from the starter switch. Always
take the SmartKey with you and lock the
vehicle. Do not leave children unattended in
the vehicle, even if they are secured in a child
restraint system, or with access to an
unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. The children
could
R injure themselves on parts of the vehicle
R be seriously or fatally injured through
excessive exposure to extreme heat or cold
R injure themselves or cause an accident with
vehicle equipment that can be operated
even if the SmartKey is removed from the
starter switch or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned by these
parts.
GWARNING
Do not carry heavy or hard objects in the
passenger compartment unless they are
firmly secured in place.
Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of:
R strong braking maneuvers
R sudden changes of direction
R an accident
General notes
If you cannot open or lock the vehicle with the
SmartKey, either the battery in the SmartKey
is empty, the SmartKey is faulty, or the starter
battery is discharged.
XCheck the battery in the SmartKey and
replace it if necessary ( Y page 78).XUnlock the driver's door with the
mechanical key ( Y page 83).XLock the vehicle ( Y page 83).XHave the starter battery and battery
contacts checked by an authorized
Mercedes-Benz Center.
If the SmartKey is faulty, contact Roadside
Assistance or an authorized Mercedes-Benz
Center.
SmartKey functions
General notes
i Only for USA:
This device complies with Part 15 of the
FCC rules. Operation is subject to the
following conditions:
1. This device must not cause any
interference, and
2. This device must be able to
accommodate interference that is
received, including interference which
could cause unwanted functions.
74SmartKeyOpening and closing

Unapproved modifications to this device
may lead to withdrawal of permission to
operate it.
The product label with FCC ID and IC
certification number can be found in the
battery case of the SmartKey.
i Only for Canada:
This device complies with Industry
Canada's RSS210 rules. Operation is
subject to the following conditions:
1. This device must not cause any
interference, and
2. This device must be able to
accommodate interference that is
received, including interference which
could cause unwanted functions.
Unapproved modifications to this device
may lead to withdrawal of permission to
operate it.
The product label with FCC ID and IC
certification number can be found in the
battery case of the SmartKey.
Locking and unlocking centrally
The SmartKey centrally locks/unlocks:
R the doors
R the trunk lid
R the fuel filler flap
:& To lock the vehicle;F To unlock the trunk lid=% To unlock 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 COMAND.
You can also set an audible signal to confirm
that the vehicle has been locked or unlocked.
The audible signal can be activated and
deactivated using the on-board computer
( Y page 350).XTo unlock centrally: press the %
button.
If you do not open a door or the trunk lid within
approximately 40 seconds of unlocking the
vehicle:
R the vehicle is locked again.
R the theft deterrent locking system is
activated again.
XTo lock centrally: press the & button.
KEYLESS-GO
General notes
i Only for USA:
This device complies with Part 15 of the
FCC rules. Operation is subject to the
following conditions:
1. This device must not cause any
interference, and
2. This device must be able to
accommodate interference that is
received, including interference which
could cause unwanted functions.
Unapproved modifications to this device
may lead to withdrawal of permission to
operate it.
The product label with FCC ID and IC
certification number can be found in the
battery case of the SmartKey.
i Only for Canada:
This device complies with Industry
Canada's RSS210 rules. Operation is
subject to the following conditions:
1. This device must not cause any
interference, and
SmartKey75Opening and closingZ

2. This device must be able to
accommodate interference that is
received, including interference which
could cause unwanted functions.
Unapproved modifications to this device
may lead to withdrawal of permission to
operate it.
The product label with FCC ID and IC
certification number can be found in the
battery case of the SmartKey.
Important information for using
KEYLESS-GO
R You can use the KEYLESS-GO key as a
conventional key.
R You can combine KEYLESS-GO functions
with those of a conventional key, e.g. open
with KEYLESS-GO and close with the
& button.
R Always carry your KEYLESS-GO key on your
person.
R Never keep the KEYLESS-GO key with:
- electronic equipment, such as your
mobile phone or another key
- metal objects, such as coins or metal foil
This may impair the functioning of
KEYLESS-GO.
R To open or close the vehicle, the KEYLESS-
GO key should be no more than 3 ft (1 m)
from the door or trunk.
R If the vehicle is parked for more than
72 hours, the KEYLESS-GO function is
deactivated. Pull one of the outer door
handles and turn on the ignition to
reactivate the KEYLESS-GO function.
R When the KEYLESS-GO key is removed
from the vehicle, it is possible that the
system may not recognize it. In this case,
the vehicle cannot be locked or started with
KEYLESS-GO.
R If the KEYLESS-GO key has been removed
from the vehicle, e.g. if a passenger leaves
the vehicle with the KEYLESS-GO key:
- while someone is holding the Start/Stop
button or attempting to lock the vehicle
using the outer door handle, the Key
Not Detected message will appear in
the multifunction display.
- while the engine is running, the red Key
Not Detected message will appear in
the multifunction display as you pull
away. Find the KEYLESS-GO key and
change its position in the vehicle. Place
the KEYLESS-GO key in a location such
as the front-passenger seat, or carry it in
your shirt pocket.
R If you have started the engine using the
Start/Stop button, you can turn if off again
by:
- pressing the Start/Stop button again
- inserting the KEYLESS-GO key into the
ignition lock when the vehicle is
stationary and the automatic
transmission is in parking position P.
R You may accidentally unlock the vehicle if
the KEYLESS-GO key is within 3 ft (1 m) of
the vehicle and:
- a jet of water splashes an outer door
handle
or
- you are cleaning an outer door handle.
R Note that the engine can be started by any
vehicle occupant if a KEYLESS-GO key is in
the vehicle.
Option 1: there is a KEYLESS-GO key in the
vehicle and a KEYLESS-GO key outside the
vehicle. If you leave the KEYLESS-GO key
behind when you get out and lock the
vehicle, a message does not appear in the
multifunction display.
Option 2: there is a KEYLESS-GO key in the
vehicle but no KEYLESS-GO key outside the
vehicle. When you get out and try to lock
the vehicle, the Key Detected in
Vehicle message appears in the
multifunction display. The vehicle is not
locked in this case.
When starting the engine and while driving,
KEYLESS-GO also checks whether a valid key76SmartKeyOpening and closing

is in the vehicle by periodically establishing
radio contact.X To unlock the vehicle: pull the door
handle.XTo lock the vehicle: touch sensor
surface :.
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 in such a way that only the driver's
door and the fuel filler flap are unlocked. This
is useful if you frequently travel on your own.
XTo change the setting: press the %
and & buttons until the battery check
lamp ( Y page 78) flashes twice.
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 : pull the door
handle on the driver's door.XTo unlock centrally: pull the door handle
on the front-passenger door.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 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 70).
There are several ways to turn off the alarm:
XTo stop the alarm with the SmartKey:
press the % or & button on the
SmartKey.
or
XInsert the SmartKey into the ignition lock.
or
XTo stop 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.SmartKey77Opening and closingZ

Problems with the SmartKeyProblemPossible causes/consequences and M SolutionsYou cannot lock or
unlock the vehicle
using the SmartKey.The SmartKey battery is discharged or nearly discharged.XPoint the tip of the SmartKey at the driver's door handle from a
distance of approximately 1.5 ft (50 cm) and try to unlock or
lock the vehicle again.
If this does not work:
XCheck the key battery and replace it if necessary ( Y page 78).XUnlock ( Y page 83) or lock ( Y page 83) the vehicle with the
mechanical key.The SmartKey is faulty.XUnlock ( Y page 83) or lock ( Y page 83) the vehicle with the
mechanical key.XHave the SmartKey checked at a qualified specialist workshop.You can no longer
lock/unlock the
vehicle using KEYLESS-
GO.KEYLESS-GO is in standby mode because the vehicle has not been
unlocked for an extended period.XPull the door handle twice and then insert the SmartKey into the
ignition lock.There is a malfunction with KEYLESS-GO.XLock/unlock the vehicle using the remote control function of
the SmartKey. Point the tip of the SmartKey at the driver's door
handle from close range and press the % or & button.XHave KEYLESS-GO checked at a qualified specialist workshop.There is interference from a powerful source of radio waves.XLock/unlock the vehicle using the remote control function of
the SmartKey. Point the tip of the SmartKey at the driver's door
handle from close range and press the % or & button.You have lost a
SmartKey.XHave the SmartKey canceled at an authorized Mercedes-Benz
Center.XReport the loss immediately to the vehicle insurers.XIf necessary, have the locks changed as well.You have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.XIf necessary, have the locks changed as well.80SmartKeyOpening and closing

ProblemPossible causes/consequences and M SolutionsThe engine cannot be
started using the
SmartKey.The on-board voltage is too low.XRemove the SmartKey and re-insert it into the ignition lock.XStart the engine within 30 seconds of inserting the SmartKey in
the ignition lock.XRepeat if necessary.
If the engine does not start after several attempts:
XCheck the starter battery and charge it if necessary .
or
XJump-start the vehicle .
or
XConsult a qualified specialist workshop.The engine cannot be
started using KEYLESS-
GO. The SmartKey is in
the vehicle.A door is open. Therefore, the SmartKey cannot be detected as
easily.XClose the door and try to start the vehicle again.There is interference from a powerful source of radio waves.XStart your vehicle with the SmartKey in the ignition lock.Doors
Important safety notes
GWARNING
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unsupervised in the
vehicle, even if they are secured in a child
restraint system, and do not give them access
to an unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. They could:
R injure themselves on vehicle parts
R be seriously or fatally injured by extreme
heat or cold
R injure themselves or have an accident with
vehicle equipment that may still be in
operation even after the SmartKey has
been removed from the ignition, such as the
seat adjustment, steering wheel
adjustment or memory function.
If children open a door, they could cause
severe or even fatal injury to other persons; if
they get out of the vehicle, they could injure
themselves when doing so or be seriously or
even fatally injured by any passing traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and a child could be burned on these
parts.GWARNING
Do not carry heavy or hard objects in the
passenger compartment unless they are
firmly secured in place.
Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of:
R strong braking maneuvers
R sudden changes of direction
R an accident
Doors81Opening and closingZ