
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 rear-
ward-facing child restraint system on the
front-passenger seat, always make sure that
the front-passenger front air bag is deactiva-
ted. Only if the PASSENGER AIR BAG OFF
indicator lamp is permanently lit (
Ypage 43)
is the front-passenger front air bag deactiva-
ted.
Always observe the child restraint system
manufacturer's installation and operating
instructions.
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. Fully
retract the seat cushion length. 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 shoul- der 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 down-
wards from the vehicle belt outlet. If neces-
sary, adjust the vehicle belt outlet and the
front-passenger seat accordingly. Always observe the child restraint system
manufacturer's installation and operating
instructions.
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 66)
Rthe rear side windows (Ypage 66)
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.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
Children in the vehicle65
Safety
Z

Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause Brake Assist to inter-
vene.
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 67).
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 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.
ETS/4ETS (Electronic Traction System)
iObserve the "Important safety notes" sec-
tion (
Ypage 67).
ETS traction control is part of ESP
®. On vehi-
cles with 4MATIC, 4ETS 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 trans-
ferred to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP
®.
Important safety notes
iObserve the "Important safety notes" sec-
tion (
Ypage 67).
GWARNING
If ESP
®is malfunctioning, ESP®is unable to
stabilize the vehicle. Additionally, further driv-
ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP
®checked at a
qualified specialist workshop.
If the å ESP®OFF warning lamp lights up
continuously, ESP®is deactivated.
If the ÷ ESP
®warning lamp lights up con-
tinuously, ESP®is not available due to a mal-
function.
Observe the information on warning lamps
(
Ypage 296) and display messages which
may be shown in the instrument cluster
(
Ypage 258).
Only use wheels with the recommended tire
sizes. Only then will ESP
®function properly.
Characteristics of ESP®
General information
If the ÷ ESP warning lamp goes out before
beginning the journey, ESP
®is automatically
active.
If ESP
®intervenes, the ÷ESP®warning
lamp flashes in the instrument cluster.
If ESP
®intervenes:
XDo not deactivate ESP®under any circum-
stances.
XOnly depress the accelerator pedal as far as
necessary when pulling away.
XAdapt your driving style to suit the prevail-
ing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle
stops moving. The engine starts automati-
cally when the driver wants to pull away again.
Driving safet ysystem s73
Safety
Z

Useful information
i
This Operator's Manual describes all
models and all standard and optional equip-
ment 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.
iRead the information on qualified special-
ist workshops (
Ypage 27).
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 theSmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
!Keep the SmartKey away from strong
magnetic fields. Otherwise, the remote
control function could be affected.
Strong magnetic fields can occur in the
vicinity 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
SmartKey.
Vehicles with KEYLESS-GO start function:
do not keep the SmartKey in the cargo com-
partment. Otherwise, the SmartKey may not
be detected, e.g. when starting the engine
using the Start/Stop button.
A check which periodically establishes a radio
connection between the vehicle and the
SmartKey determines whether a valid Smart-
Key is in the vehicle. This occurs, for example:
Rwhen starting the engine
Rwhilst driving
Rwhen the external door handles are
touched
Rduring convenience closing
82SmartKey
Opening and closing

XTurn the SmartKey to position2in the igni-
tion lock (
Ypage 153).
XPress button =for the exterior mirror on
the front-passenger side.
XEngage reverse gear.
The exterior mirror on the front-passenger
side moves to the preset parking position.
XUse adjustment button ;to adjust the
exterior mirror to a position that allows you
to see the rear wheel and the curb.
The parking position is stored.
iIf you shift the transmission to another
position, the exterior mirror on the front-
passenger side returns to the driving posi-
tion.
Using the memory button
You can store the parking position of the
exterior mirror on the front-passenger side
using memory button M:. The reverse gear
must not be engaged.
XTurn the SmartKey to position 2in the igni-
tion lock (
Ypage 153).
XPress button =for the exterior mirror on
the front-passenger side.
XUse adjustment button ;to adjust the
exterior mirror to a position that allows you
to see the rear wheel and the curb.
XPress memory button M: and one of the
arrows on adjustment button ;within
three seconds.
The parking position is stored if the exterior mirror does not move.
XIf the mirror moves out of position, repeat
the steps.
XAfter successfully storing, reset the driving
position of the exterior mirror.
Calling up a stored parking position set-
ting
XTurn the SmartKey to position 2in the igni-
tion lock (
Ypage 153).
XAdjust the exterior mirror on the front-
passenger side using button =.
XEngage reverse gear.
The exterior mirror on the front-passenger
side moves to the stored parking position.
The exterior mirror on the front-passenger
side moves back to its original position:
Ras soon as you exceed a speed of 9 mph
(15 km/h)
Rabout ten seconds after you have disen-
gaged reverse gear
Rif you press button ?for the exterior mir-
ror on the driver's side
Memory function
Important safety notes
GWARNING
If you use the memory function on the driver's side while driving, you could lose control of
the vehicle as a result of the adjustments
being made. There is a risk of an accident.
Only use the memory function on the driver's
side when the vehicle is stationary.
GWARNING
When the memory function adjusts the seat or steering wheel, you and other vehicle occu-
pants – particularly children – could become
trapped. There is a risk of injury.
While the memory function is making adjust-
ments, make sure that no one has any body
parts in the sweep of the seat or steering
wheel. If somebody becomes trapped, imme-
diately release the memory function position
button. The adjustment process is stopped.
Memory function121
Seats, steering wheel and mirrors
Z

Useful information............................152
Notes on breaking-in a new vehi-
cle ....................................................... 152
Driving ............................................... 152
DYNAMIC SELECT switch .................161
Automatic transmission ...................161
Refueling ............................................ 169
Parking ............................................... 172
Driving tips ........................................ 176
Driving systems ................................ 181
Towing a trailer ................................. 227
151
Driving and parking

GWARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
Roverheat and cause a fire
Rlose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
!Do not warm up the engine with the vehi-
cle stationary. Drive off immediately. Avoid
high engine speeds and driving at full throt-
tle until the engine has reached its operat-
ing temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
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 igni-
tion lock even if it is not the correct Smart- Key for the vehicle. The ignition is not
switched on. The engine cannot be started.
Start/Stop button
General notes
When you insert the Start/Stop button into
the ignition lock, the system needs approx-
imately 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.
A check which periodically establishes a radio
connection between the vehicle and the
SmartKey determines whether a valid Smart-
Key is in the vehicle. This occurs, for example,
when starting the engine.
Driving153
Driving and parking
Z

Removing the Start/Stop button
You can remove the Start/Stop button from
the ignition lock and start the vehicle as nor-
mal using the SmartKey.
It is only possible to switch between Start/
Stop button mode and SmartKey operation
when the transmission is in positionP.
XRemove Start/Stop button:from ignition
lock ;.
You do not have to remove the Start/Stop
button from the ignition lock when you leave
the vehicle. You should, however, always take
the SmartKey with you when leaving the vehi-
cle. As long as the SmartKey is in the vehicle:
Rthe vehicle can be started using the Start/
Stop button
Rthe electrically powered equipment can be
operated
Starting the engine
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
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation.
GWARNING
Flammable materials introduced through
environmental influence or by animals can
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.
!Do not depress the accelerator when
starting the engine.
General notes
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 162).
The transmission position display in the
multifunction display shows
P (
Ypage 163).
iYou can start the engine in transmission
position Pand N.
Starting procedure with the SmartKey
To start the engine using the SmartKey
instead of the Start/Stop button, pull the
Start/Stop button out of the ignition lock.
XTurn the SmartKey to position 3in the igni-
tion lock and release it as soon as the
engine is running (
Ypage 153).
Driving155
Driving and parking
Z

Make sure that the engine cannot be started
via your smartphone before carrying out
maintenance or repairs. You can prevent an
engine start via your smartphone, for exam-
ple, 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 pull-
ing 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, see the Digital Operator's Manual.
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 converter to reach its operating
temperature more quickly.
Information on the automatic release of the
electric parking brake (
Ypage 174).
Pulling away with a trailer
To ensure that you do not roll backwards
when pulling away on an uphill slope, engage
the electric parking brake.
XPress and hold handle :.
The electric parking brake continues to
brake and prevent the vehicle from rolling
backwards.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument clus-
ter remains on.
XDepress the accelerator pedal.
XAs soon as the vehicle/trailer combination
is held 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 clus-
ter goes out.
For further information on the electric parking
brake, see (
Ypage 174).
Hill start assist
Hill start assist helps you when pulling away
forwards 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.
Driving157
Driving and parking
Z