
Child restraint system on the front-
passenger seat
General notes
Accident statistics show that children secured
in the rear seats are safer than children secured
in the front-passenger seat. For this reason,
Mercedes-Benz strongly advises that you install
the child restraint system on a rear seat.
If it is absolutely necessary to install a child
restraint system on the front-passenger seat,
always observe the instructions and safety
notes on the "Occupant Classification System
(OCS)" (
Ypage 48).
You can thus avoid the risks that could arise as a result of:
Ran incorrectly categorized person in the front-
passenger seat
Rthe unintentional deactivation of the front-
passenger front air bag
Rthe unsuitable positioning of the child
restraint system, e.g. too close to the dash-
board
Rearward-facing child restraint system
If it is absolutely necessary to install a rearward-
facing child restraint system on the front-
passenger seat, always make sure that the
front-passenger front air bag is deactivated.
Only if the PASSENGER AIR BAG OFF indicator
lamp is permanently lit (
Ypage 42) is the front-
passenger front air bag deactivated.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Forward-facing child restraint system
If it is absolutely necessary to install a forward-
facing child restraint system on the front-
passenger seat, always move the front-
passenger seat as far back as possible. The
entire base of the child restraint system must
always rest on the seat cushion of the front-
passenger seat. The backrest of the child
restraint system must lie as flat as possible
against the backrest of the front-passenger
seat. The child restraint system must not touch
the roof or be subjected to a load by the head
restraint. Adjust the angle of the seat backrest
and the head restraint position accordingly.
Always make sure that the shoulder belt strap is correctly routed from the vehicle belt outlet to
the shoulder belt guide on the child restraint
system. The shoulder belt strap must be routed
forwards and downwards from the vehicle belt
outlet. If necessary, adjust the vehicle belt out-
let and the front-passenger seat accordingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Child-proof locks
Important safety notes
GWARNING
If children are traveling in the vehicle, they
could:
Ropen doors, thus endangering other people
or road users
Rexit the vehicle and be caught by oncoming
traffic
Roperate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle.
Override feature for:
Rthe rear doors (Ypage 62)
Rthe rear side windows (Ypage 62)
GWARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example:
Rrelease the parking brake.
Rshift the automatic transmission out of the
parking position P.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
Children in the vehicle61
Safety
Z

are in the path of your vehicle for an extended
period of time.
If adaptive Brake Assist detects a risk of colli-
sion with the vehicle in front, it calculates the
braking force necessary to avoid a collision. If
you apply the brakes forcefully, adaptive Brake
Assist will automatically increase the braking
force to a level suitable for the traffic conditions.
Adaptive Brake Assist provides braking assis-
tance in hazardous situations at speeds above
4 mph (7 km/h). It uses radar sensor technology
to assess the traffic situation.
Up to a speed of approximately 155 mph
(250km/ h), Adaptive Brake Assist is capable of
reacting to moving objects that have already
been detected as such at least once over the
period of observation.
Up to a speed of approximately 44 mph
(70 km/ h), Adaptive Brake Assist reacts to sta-
tionary obstacles.
If adaptive Brake Assist demands particularly
high braking force, preventative passenger pro-
tection measures (PRE-SAFE
®) are activated
simultaneously (Ypage 55).
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:
Ryou release the brake pedal.
Rthere is no longer any danger of a collision.
Rno obstacle is detected in front of your vehi-
cle.
Adaptive Brake Assist is then deactivated.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 63).
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
Rintervene unnecessarily
Rnot intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
GWARNING
Adaptive Brake Assist does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen cornering
As a result, the Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause Brake Assist to intervene.
If adaptive Brake Assist 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)
General notes
iObserve the "Important safety notes" sec-
tion (Ypage 63).
ESP
®monitors driving stability and traction, i.e.
power transmission between the tires and the
road surface.
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. The
engine output is also modified to keep the vehi-
cle 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.
ETS/4ETS (Electronic Traction System)
4ETS traction control is part of ESP®.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is transfer-
red to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP
®.
66Driving safety systems
Safety

SmartKey
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
GWARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
!Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey.
Rwith metallic objects, e.g. coins or metal foil.
Rinside metallic objects, e.g. a metal case.
This can affect the functionality of the Smart- Key. Do not keep the KEYLESS-GO or KEYLESS-GO
Start function key in the temperature-controlled
cup holder. Otherwise, the KEYLESS-GO or KEY-
LESS-GO Start function key will not be detected.
Vehicles with KEYLESS-GO start function:
do
not keep the SmartKey in the cargo compart-
ment. Otherwise, the SmartKey may not be
detected, e.g. when starting the engine using
the Start/Stop button.
SmartKey functions
:& Locks the vehicle
;FOpens/closes the tailgate
=%Unlocks the vehicle
XTo unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
Rthe vehicle is locked again.
Ranti-theft protection is reactivated.
XTo lock centrally: press the&button.
The SmartKey centrally locks and unlocks the
following components:
Rthe doors
Rthe tailgate
Rthe fuel filler flap
The turn signals flash once when unlocking and
three times when locking.
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 (
Ypage 239).
You will receive visual and acoustic locking con-
firmation if all components were able to be
locked.
74SmartKey
Opening and closing

!Do not warm up the engine with the vehicle
stationary. Drive off immediately. Avoid high
engine speeds and driving at full throttle until
the engine has reached its operating temper- ature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
!Mercedes-AMG vehicles: at low engine oil
temperatures below 68 ‡ (+20 †), the max-
imum engine speed is restricted in order to
protect the engine. To protect the engine and
maintain smooth engine operation, avoid driv-
ing at full throttle when the engine is cold.
SmartKey positions
SmartKey
gTo remove the SmartKey
1Power supply for some consumers, such as
the windshield wipers
2Ignition (power supply for all consumers)
and drive position
3To start the engine
iThe SmartKey can be turned in the ignition
lock even if it is not the correct SmartKey for
the vehicle. The ignition is not switched on.
The engine cannot be started.
KEYLESS-GO
General notes
Vehicles with KEYLESS-GO are equipped with a
SmartKey featuring an integrated KEYLESS-GO
function and a detachable Start/Stop button. A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example, when
starting the engine.
When you insert the Start/Stop button into the
ignition lock, the system needs approximately
two seconds recognition time. You can then use
the Start/Stop button.
Pressing the Start/Stop button several times in
succession corresponds to the different key
positions in the ignition lock. This is only the
case if you are not depressing the brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
To start the vehicle without actively using the
SmartKey:
Rthe Start/Stop button must be inserted in the
ignition lock.
Rthe SmartKey must be in the vehicle.
Rthe vehicle must not be locked with the
SmartKey or KEYLESS-GO (Ypage 75).
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey.
Rwith metallic objects, e.g. coins or metal foil.
Rinside metallic objects, e.g. a metal case.
This can impair the functionality of the KEY-
LESS-GO key.
Do not keep the KEYLESS-GO key in the tem-
perature-controlled cup holder (
Ypage 303).
Otherwise, the KEYLESS-GO key will not be rec-
ognized.
If you lock the vehicle with the SmartKey's
remote control or with KEYLESS-GO, after a
short time:
Ryou will not be able to switch on the ignition
with the Start/Stop button.
Ryou will not be able to start the engine with the
Start/Stop button until the vehicle is
unlocked again.
If you lock the vehicle centrally using the button
on the front door (
Ypage 80), you can continue
to start the engine with the Start/Stop button.
The engine can be switched off while the vehicle
is in motion by pressing and holding the Start/
Stop button for three seconds. This function
operates independently of the ECO start/stop
automatic engine switch-off function.
138Driving
Driving and parking

Key positions with KEYLESS-GO
:Start/Stopbutto n
;Ignition loc k
As soo nas th eignition is switched on ,all th e
indicator lamps in th einstrumen tcluste rligh t
up. Further information on situation swher ean
indicator lamp either fails to go out after starting
th eengin eor lights up while driving
(
Ypage 276).
If Start/Sto pbutto n: has no tyet been
pressed, this correspond sto th eke ybein g
remove dfrom th eignition .
XTo switch on th epower supply :press
Start/Sto pbutto n: once.
The power suppl yis switched on .You can no w
activat eth ewindshield wipers, for example .
The power suppl yis switched off again if:
Rth edriver' sdoor is opened and
Ryou press Start/Sto pbutto n: twice when in
this position
XTo switch on th eignition: press Start/Sto p
butto n: twice.
The ignition is switched on .
If you press Start/Sto pbutto n: once when
in this position ,th eignition is switched off
again .
Removing the Start/S topbutton
You can remove th eStart/Sto pbutto nfrom th e
ignition loc kand start th evehicl eas normal
usin gth eSmartKey.
It is only possible to switch between KEYLESS -
GO mod eand SmartKey operation when th e
transmission is in position P.
XRemove Start/Stopbutto n: from ignition
loc k;. You do no
thave to remove th eStart/Sto pbut -
to nfrom th eignition loc kwhen you leav eth e
vehicle. You should, however ,always tak eth e
SmartKey wit hyou when leaving th evehicle. As
lon gas th eSmartKey is in th evehicle:
Rth evehicl ecan be started usin gth eStart /
Stop butto n
Rtheelectrically powered equipmen tcan be
operate d
Starting the engine
Important safety notes
GWARNIN G
If children are lef tunsupervised in th evehicle,
they could:
Ropen th edoors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate th evehicle's equipment.
Additionally, children could set th evehicl ein
motion if, for example ,they:
Rrelease th eparking brake.
Rshiftin gth eautomatic transmission out of
park positio nP
RStart th eengine.
Ther eis aris kof an acciden tand injury.
When leaving th evehicle, always tak eth e
SmartKey wit hyou and loc kth evehicle. Never
leav echildren or animals unattended in th e
vehicle. Always keep th eSmartKey out of
reac hof children .
GWARNING
Combustion engines emit poisonous exhaust
gase ssuc has carbon monoxide. Inhalin g
these exhaust gase sleads to poisoning .Ther e
is aris kof fatal injury. Therefore never leav e
th eengin erunnin gin enclosed spaces with-
out sufficien tventilation .
GWARNING
Flammable materials introduce dthroug h
environmental influence or by animals can
Driving139
Driving and parking
Z

ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
General notes
Vehicles with a gasoline engine:the catalytic
converter is preheated for up to 30 seconds
after a cold start. The sound of the engine may
change during this time.
Automatic transmission
XShift the transmission to position P
(Ypage 146).
The transmission position display in the mul-
tifunction display shows P(
Ypage 148).
iYou can start the engine in transmission
position Pand N.
Starting procedure with the SmartKey
XTo start a diesel engine : turn the SmartKey
to position 2in the ignition lock (Ypage 138).
The % preglow indicator lamp in the instru-
ment cluster lights up.
XTurn the SmartKey to position 3in the ignition
lock and release it as soon as the engine is
running (
Ypage 138).
iVehicles with a diesel engine: you can
start the engine without preglow if the engine
is warm.
Using KEYLESS-GO to start the engine
The Start/Stop button can be used to start the
vehicle without inserting the SmartKey into the
ignition lock. The Start/Stop button must be
inserted in the ignition lock and the SmartKey
must be in the vehicle. This mode for starting the
engine operates independently of the ECO
start/stop automatic engine start function.
XDepress the brake pedal and keep it
depressed.
XPress the Start/Stop button once
(Ypage 138).
Vehicles with a gasoline engine: the engine
starts.
Vehicles with a diesel engine: preglow is
activated and the engine starts.
Starting procedure via smartphone
Observe the important safety notes on starting
the engine (Ypage 139).
You can also start your engine via your smart-
phone from outside the vehicle. In this case, the
previously selected climate control setting is
activated. In this way you can cool or heat the
interior of the vehicle before starting the jour-
ney.
Only start the engine via your smartphone if it is
safe to start and run the engine where your vehi-
cle is parked.
Observe the legal stipulations in the area where your vehicle is parked. Engine start via smart-
phone may be limited to certain countries or
regions.
You can execute a maximum of two consecutive
starting attempts via your smartphone. If you
insert the SmartKey into the ignition lock, you
can carry out two more starting attempts.
Once you have started the engine, you can
switch the engine off via your smartphone at any
time.
You can only start the engine via your smart-
phone if:
Rthe SmartKey is in the ignition lock
Rpark position Pis selected
Rthe accelerator pedal is not depressed
Rthe anti-theft alarm system is not activated
Rthe panic alarm is not activated
Rthe hazard warning lamps are switched off
Rthe hood is closed.
Rthe doors are closed and locked
Rthe windows and sliding sunroof are closed
Also make sure that:
Rthe fuel tank is sufficiently filled
Rthe starter battery is sufficiently charged
140Driving
Driving and parking

GWARNING
Limbs could be crushed or trapped if the
engine is started unintentionally during ser-
vice or maintenance work. There is a risk of
injury.
Always secure the engine against uninten-
tional starting before carrying out mainte-
nance or repair work.
Make sure that the engine cannot be started via
your smartphone before carrying out mainte-
nance or repairs. You can prevent an engine
start via your smartphone, for example, if you:
Rswitch on the hazard warning lamps
Rdo not lock the doors
Ropen the hood
Pulling away
General notes
GWARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is
a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate.
Depress the accelerator carefully when pulling
away.
The vehicle locks centrally once you have pulled
away. The locking knobs in the doors drop down.
You can open the doors from the inside at any
time.
You can also deactivate the automatic locking
feature (
Ypage 239).
It is only possible to shift the transmission from
position Pto the desired position if you depress
the brake pedal. Only then is the parking lock
released. If you do not depress the brake pedal,
the DIRECT SELECT lever can still be moved but the parking lock remains engaged.
iUpshifts take place at higher engine speeds
after a cold start. This helps the catalytic con-
verter to reach its operating temperature
more quickly. Information on the automatic release of the
electric parking brake (
Ypage 161).
Pulling away with a trailer
To ensure that you do not roll backwards when
pulling away on an uphill slope, engage the elec-
tric parking brake.
XPress and hold handle
:.
The electric parking brake continues to brake
and prevent the vehicle from rolling back-
wards.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument cluster remains on.
XDepress the accelerator pedal.
XAs soon as the vehicle/trailer combination isheld by the driving force of the engine, release
lever :.
the electric parking brake is released.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument cluster goes out.
Hill start assist
Hill start assist helps you when pulling away for-
wards or in reverse on an uphill gradient. It holds
the vehicle for a short time after you have
removed your foot from the brake pedal. This
gives you enough time to move your foot from
the brake pedal to the accelerator pedal and to
depress it before the vehicle begins to roll.
GWARNING
After a short time, hill start assist will no lon-
ger brake your vehicle and it could roll away.
There is a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
Driving141
Driving and parking
Z

leave the vehicle when it is held by hill start
assist.
Hill start assist is not active if:
Ryou are pulling away on a level road or on a
downhill gradient.
Rthe transmission is in position N.
Rthe electric parking brake is applied.
RESP®is malfunctioning.
ECO start/stop function
Introduction
The ECO start/stop function switches the
engine off automatically if the vehicle is stopped
under certain conditions.
The engine starts automatically when the driver
wants to pull away again. The ECO start/stop
function thereby helps you to reduce the fuel
consumption and emissions of your vehicle.
Important safety notes
GWARNING
If the engine is switched off automatically and
you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving.
There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes
:ECO start/stop display
The ECO start/stop function is activated when-
ever you start the engine using the SmartKey or the Start/Stop button.
If the engine has been switched off automati-
cally by the ECO start/stop function, the èECO symbol is shown in the multifunction dis-
play.
Mercedes-AMG vehicles: the ECO start/stop
function is only available in drive programs
Comfort andSlippery.
Automatic engine switch-off
If the vehicle is braked to a standstill in Dor N,
the ECO start/stop function switches off the
engine automatically.
The ECO start/stop function is operational
when:
Rthe indicator lamp in the ECO button is lit
green.
Rthe Sport Plus orSport drive program is not
selected (Mercedes-AMG vehicles)
Rno off-road program has been selected
Rthe outside temperature is within the range
that is suitable for the system
Rthe engine is at normal operating temperature
Rthe set temperature for the vehicle interior
has been reached
Rthe battery is sufficiently charged
Rthe system detects that the windshield is not
fogged up when the air-conditioning system is switched on
Rthe hood is closed
Rthe driver's door is closed and the driver's
seat belt is fastened
All of the vehicle's systems remain active when
the engine is stopped automatically.
The HOLD function can also be activated if the
engine has been switched off automatically. It is
then not necessary to continue applying the
brakes during the automatic stop phase. When
you depress the accelerator pedal, the engine
starts automatically and the braking effect of
the HOLD function is deactivated.
All vehicles (except Mercedes-AMG vehi-
cles): automatic engine switch-off can take
place a maximum of four times in a row (initial
stop, then three subsequent stops).
Mercedes-AMG vehicles: the number of con-
secutive automatic engine switch-offs is unlimi-
ted.
142Driving
Driving and parking