
Special seat belt retractor
The seat belt on the front-passenger side is
equipped with a special seat belt retractor.
When activated, the special seat belt
retractor ensures the seat belt will not
slacken once the child restraint system has
been secured.
Installing a child restraint system:
XAlways comply with the manufacturer's
installation instructions.XPull the seat belt smoothly from the inertia
reel.XEngage the seat belt tongue in the belt
buckle.
Activating the special seat belt retractor:
XPull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat
belt retractor is enabled.XPush down on the child restraint system to
take up any slack.
Removing a child restraint system/
deactivating the special seat belt retractor:
XAlways comply with the manufacturer's
installation instructions.XPress the seat belt release button and
guide the belt tongue to the belt outlet.
The special seat belt retractor is
deactivated.GWARNING
Never release the seat belt buckle while the
vehicle is in motion, since the special seat belt
retractor will be deactivated.
Panic alarmX To activate: press ! button : for at
least one second.
An alarm sounds and the exterior lighting
flashes.XTo deactivate: press ! button :
again.
or
XInsert the SmartKey into the ignition lock.
or
XPress the KEYLESS-GO Start/Stop button.
The KEYLESS-GO key must be in the
vehicle.
i USA only:
This device complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
The product label with FCC ID and IC
certification number can be found in the
battery case of the SmartKey.
i Canada only:
This device complies with RSS-Gen of
Industry Canada. Operation is subject to
the following two conditions:
Panic alarm55SafetyZ

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

XTo switch off: press button :.
The å ESP®
OFF warning lamp in the
instrument cluster lights up.GWARNING
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.
XTo switch on: press button :.
The å ESP®
OFF warning lamp in the
instrument cluster goes out.
Deactivating/activating ESP ®
(AMG
vehicles)
Activating/deactivating SPORT handling
mode
GWARNING
The SPORT handling mode should not be
switched on during normal driving.
Switching on the SPORT handling mode will
result in the following:
R no restriction to the engine torque
R system supported traction control is
limited
The SPORT handling mode is designed for
driving on closed tracks when the vehicle's
own natural oversteer and understeer
characteristics are desired and requires a
highly skilled and experienced driver able to
handle these critical driving situations.
You could lose control of your vehicle and
cause an accident.
Please be aware of these limits when you
switch on the SPORT handling mode.
Do not switch on the SPORT handling when a
spare wheel is mounted.
ESP ®
is activated automatically when the
engine is started.
i Vehicles with ECO start/stop function:
the ECO start/stop function switches the
engine off automatically when the vehicle
comes to a stop. The engine starts
automatically when the driver wants to pull
away again. ESP ®
remains in its previously
selected status. Example: if ESP ®
was
deactivated before the engine was
switched off, ESP ®
remains deactivated
when the engine is switched on again.
It may be best to activate SPORT handling
mode in the following situations:
R when using snow chains
R in deep snow
R on sand or gravelGWARNING
Switch off the SPORT handling mode and
switch on the ESP ®
immediately if the
aforementioned circumstances do not apply
anymore. Otherwise the SPORT handling
mode will only stabilize the vehicle to a limited
extent when it is starting to skid or a wheel is
spinning.
When SPORT handling mode is activated:
R ESP ®
only improves driving stability to a
limited degree.
R engine torque is only restricted to a limited
degree, and the drive wheels are able to
spin. The spinning wheels produce a
cutting effect for better traction.
R traction control is still activated.
R ESP ®
still provides support when you brake
firmly.
60Driving safety systemsSafety

If SPORT handling mode is activated and one
or more wheels start to spin, the ÷ ESP®
warning lamp in the instrument cluster
flashes. ESP ®
only stabilizes the vehicle to a
limited degree.XTo activate: briefly press button :.
The M SPORT handling mode warning
lamp in the instrument cluster lights up.
The SPORT handling mode message
appears in the multifunction display.XTo deactivate: briefly press button :.
The M SPORT handling mode warning
lamp in the instrument cluster goes out.
Deactivating/activating ESP ®
GWARNING
The ESP
®
should not be switched off during
normal driving.
Disabling of the system will result in the
following:
R no restriction to engine torque
R loss of system-supported traction control
"ESP ®
OFF" is designed for driving on closed
tracks when the vehicle's natural oversteer
and understeer characteristics are desired
and requires a highly skilled and experienced
driver able to handle these critical driving
situations.
You could lose control of your vehicle and
cause an accident.
Please be aware of these limits when you
switch off the ESP ®
.
Do not switch off the ESP ®
when a spare
wheel is mounted.
ESP ®
is activated automatically when the
engine is started.
i Vehicles with ECO start/stop function:
the ECO start/stop function switches the
engine off automatically when the vehicle
comes to a stop. The engine starts
automatically when the driver wants to pull
away again. ESP ®
remains in its previously
selected status. Example: if ESP ®
was
deactivated before the engine was
switched off, ESP ®
remains deactivated
when the engine is switched on again.
It may be best to deactivate ESP ®
in the
following situations:
R when using snow chains
R in deep snow
R on sand or gravelGWARNING
Switch on ESP ®
immediately if one of the
previously stated conditions is no longer met.
Otherwise, ESP ®
cannot stabilize the vehicle
if it begins to lurch or when a wheel spins.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin. The spinning
wheels produce a cutting effect for better
traction.
R traction control is still activated.
R PRE-SAFE ®
is no longer available, nor is it
activated if you brake firmly and ESP ®
intervenes.
R PRE-SAFE ®
Brake is no longer available,
nor is it activated if you brake firmly and
ESP ®
intervenes.
R ESP ®
still provides support when you brake
firmly.
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
Driving safety systems61SafetyZ

the instrument cluster does not flash. In such
situations, ESP ®
will not stabilize the vehicle.XTo deactivate: press button : until the
å ESP®
OFF warning lamp lights up in
the instrument cluster.
The ÷ OFF message appears in the
multifunction display.GWARNING
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.
XTo activate: briefly press button :.
The å ESP®
OFF warning lamp in the
instrument cluster goes out. The ÷ON
message appears in the multifunction
display.EBD (electronic brake force
distribution)
i Observe the "Important safety notes"
section ( Y page 56).
EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking.GWARNING
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.
XObserve the notes on warning and indicator
lamps ( Y page 230) as well as display
messages ( Y page 202).
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 168) and hill start assist
( Y page 134). For further information, see
Driving tips ( Y page 153).
PRE-SAFE ®
Brake
PRE-SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
i Observe the "Important safety notes"
section ( Y page 56).
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
62Driving 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

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 23).
SmartKey
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
If a key ring is too heavy or too large, the
weight acting on the key could cause it to turn
in the ignition lock or catch on the steering
wheel. This could cause the engine to be
switched off suddenly. You may lose control
of the vehicle and cause an accident. Do not
attach any heavy or large key rings to the key
that is inserted in the ignition.
General notes
If you cannot lock or unlock the vehicle with
the SmartKey, either the battery in the
SmartKey is discharged, the SmartKey is
faulty or the starter battery is discharged.
XCheck the battery in the SmartKey and
replace it if necessary ( Y page 71).XUnlock the driver's door using the
mechanical key ( Y page 76).XLock the vehicle using the mechanical key
( Y page 76).XHave the starter battery and the battery
contacts checked at a qualified specialist
workshop.
If the SmartKey is faulty, contact Roadside
Assistance or a qualified specialist workshop.
SmartKey functions
The SmartKey centrally locks/unlocks:
R the doors
R the trunk lid
R the glove box
R the stowage compartment in the center
console
R the fuel filler flap
68SmartKeyOpening/closing

:& 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