snow chains. Only in this way will the
driving safety systems described in this
section work as effectively as possible. ABS (Anti-lock Braking System)
General information ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
The 0025 ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Important safety notes i
Observe the "Important safety notes"
section (Y page 70). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking
characteristics may be severely impaired.
Additionally, further driving safety systems
are deactivated. There is an increased danger
of skidding and accidents.
Drive on carefully. Have ABS checked
immediately at a qualified specialist
workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp (Y page 304) and
display messages which may be shown in the
instrument cluster (Y page 266).
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface
conditions. ABS works on slippery surfaces,
even when you only brake gently. Braking X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking
situation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving. BAS (Brake Assist System)
General information BAS operates in emergency braking
situations. If you depress the brake pedal
quickly, BAS automatically boosts the braking
force, thus shortening the stopping distance.
Important safety notes
i
Observe the "Important safety notes"
section (Y page 70). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep 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. Driving safety systems
71Safety Z
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section (Y page 70).
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) i
Observe the "Important safety notes"
section (Y page 70).
ETS/4ETS traction control is part of ESP ®
.
Traction control brakes the drive wheels
individually 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
transferred to the wheel or wheels with
traction.
Traction control remains active, even if you
deactivate ESP ®
.
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further
driving safety systems are deactivated. This
increases the risk of skidding and an accident. Drive on carefully. Have ESP
®
checked at a
qualified specialist workshop.
! Vehicles with 4MATIC: switch off the
ignition when the electric parking brake is
being tested on a brake dynamometer.
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
Vehicles without 4MATIC: observe the notes
on ESP ®
(Y page 377) when towing the
vehicle with a raised rear axle.
ESP ®
is deactivated if the 00BBwarning lamp
in the instrument cluster lights up
continuously when the engine is running.
If the 00E5 warning lamp lights up
continuously, ESP ®
is not available due to a
malfunction.
Observe the information on warning lamps
(Y page 305) and display messages which
may be shown in the instrument cluster
(Y page 266).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly.
Characteristics of ESP ® General information
If the
00E5 ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the 00E5ESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any
circumstances.
X Only depress the accelerator pedal as far
as necessary when pulling away.
X Adapt your driving style to suit the
prevailing road and weather conditions. 76
Driving safety systemsSafety
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle
stops moving. 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.
Deactivating/activating ESP ®Important safety notes
i
Observe the "Important safety notes"
section (Y page 70).
You can select between the following states
of ESP ®
:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer
stabilizes the vehicle. There is an increased
risk of skidding and an accident.
Only deactivate ESP ®
in the situations
described in the following.
It may be best to deactivate ESP ®
in the
following situations:
R when using snow chains
R in deep snow
R on sand or gravel
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilize the
vehicle if the vehicle starts to skid or a
wheel starts to spin.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain. Deactivating/activating ESP
®
You can deactivate or activate ESP ®
via the
on-board computer.
X To deactivate:(Y page 77).
The 00BB ESP®
OFF warning lamp in the
instrument cluster lights up.
X To activate: (Ypage 77).
The 00BB ESP®
OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the 00E5ESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
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 of the wheels results in a
cutting action for better traction on loose
surfaces.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
Crosswind driving assistance General information
Vehicles with MAGIC BODY CONTROL:
information on stabilizing the vehicle in the
event of crosswind (Y
page 213).
Strong crosswinds can cause your vehicle to
deviate from a straight course. The crosswind
driving assistance function integrated into
ESP ®
significantly reduces these effects.
ESP ®
intervenes automatically according to
the direction and intensity of the crosswinds
affecting your vehicle.
ESP stabilities the vehicle with braking
interventions to assist you in keeping the
vehicle in the lane.
Crosswind driving assistance is active at
vehicle speeds above 50 mph (80 km/h) Driving safety systems
77Safety Z
system checked at a qualified specialist
workshop.
Function X
To activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer (Y page 260).
If the PRE-SAFE ®
Brake is not activated, the
00D4 symbol appears in the multifunction
display.
Starting at a speed of around 4 mph
(7 km/h), this function warns you if you
rapidly approach a vehicle in front. An
intermittent warning tone will then sound and
the 00BA distance warning lamp will light up
in the instrument cluster.
X Brake immediately to defuse the situation.
or
X Take evasive action provided it is safe to do
so.
i If there is an increased risk of collision,
preventive passenger protection measures
(PRE-SAFE ®
) are activated.
If the risk of collision with the vehicle in front
remains and you do not brake, take evasive
action or accelerate significantly, the vehicle
may perform automatic emergency braking,
up to the point of full brake application.
Automatic emergency braking is not
performed until immediately prior to an
imminent accident.
You can prevent the intervention of the PRE-
SAFE ®
Brake at any time by:
R depressing the accelerator pedal further
R activating kickdown.
R releasing the brake pedal
The braking action of PRE-SAFE ®
Brake is
ended automatically if:
R you maneuver to avoid the obstacle.
R there is no longer a risk of collision.
R there is no longer an obstacle detected in
front of your vehicle. STEER CONTROL
General information STEER CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in
particular if:
R
both right wheels or both left wheels are on
a wet or slippery road surface when you
brake.
R the vehicle starts to skid.
Important safety notes i
Observe the "Important safety notes"
section (Y page 70).
No steering support is provided from STEER
CONTROL, if:
R ESP ®
is malfunctioning.
R the steering is malfunctioning.
Power steering will, however, continue to
function. Theft deterrent locking system
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
X To activate with the SmartKey: remove
the SmartKey from the ignition lock.
X To activate with KEYLESS-GO: switch the
ignition off and open the driver's door.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle.
Anyone can start the engine if a valid
SmartKey has been left inside the vehicle.
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 80
Theft deterrent locking systemSafety
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 Read the information on qualified
specialist workshops: (Y page 27).SmartKey
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start 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. G
WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle. G
WARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be
unintentionally 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
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:
R with electronic devices, e.g. a mobile
phone or another SmartKey
R with metallic objects, e.g. coins or metal
foil
R inside metallic objects, e.g. a metal case
This can affect the functionality of the
SmartKey.
Do not keep the SmartKey in the
temperature-controlled cup holder
(Y page 323). On vehicles without KEYLESS-
GO, do not keep it on the parcel shelf or in the
trunk. 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
SmartKey is in the vehicle. This occurs, for
example:
R when starting the engine
R whilst driving
R when the external door handles are
touched
R during convenience closing 84
SmartKeyOpening and closing
SmartKey functions
0043
0037 To lock the vehicle
0044 0054 To open/close the trunk lid
0087 0036 To unlock the vehicle
X To unlock centrally: press button0087.
If you do not open the vehicle within
approximately 40 seconds of unlocking:
R the vehicle is locked again.
R the anti-theft alarm system is armed
again.
X To lock centrally: press button0043.
The SmartKey centrally locks/unlocks:
R the doors
R the trunk lid
R the fuel filler flap
The turn signals flash once when unlocking
and three times when locking.
i You can also set an audible signal to
confirm that the vehicle has been locked.
The audible signal can be activated and
deactivated using COMAND (see the
separate operating instructions).
i When the surround lighting is activated in
COMAND, it comes on when it is dark after
the vehicle is unlocked using the remote
control. Information on activating and
deactivating the surround lighting can be
found in the separate operating
instructions. X
To open the trunk lid automatically
from outside the vehicle: press and hold
button 0044until the trunk lid opens. KEYLESS-GO
General notes Bear in mind that the engine can be started
by any of the vehicle occupants if there is a
SmartKey in the vehicle.
Locking/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
functions of KEYLESS-GO with those of a
conventional SmartKey. Unlock the vehicle
by using KEYLESS-GO, for instance, and lock
it using the
0037button on the SmartKey.
When locking or unlocking with KEYLESS-GO,
the distance between the SmartKey and the
corresponding door handle must not be
greater than 3 ft (1 m).
A check which periodically establishes a radio
connection between the vehicle and the
SmartKey determines whether a valid
SmartKey is in the vehicle. This occurs, for
example:
R when starting the engine
R whilst driving
R when the external door handles are
touched
R during convenience closing SmartKey
85Opening and closing Z
Problem Possible causes/consequences and
0050
0050Solutions The engine cannot be
started using the
SmartKey. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 371).
or
X Jump-start the vehicle (Y page 373).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the Start/
Stop button. The
SmartKey is in the
vehicle. The vehicle is locked.
X
Unlock the vehicle and try to start the vehicle again. There is interference from a powerful source of radio waves.
X
Start your vehicle with the SmartKey in the ignition lock. You have lost a
SmartKey. X
Have the SmartKey deactivated at a qualified specialist
workshop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment. Additionally, children could set the vehicle in
motion if, for example, they:
R
release the parking brake.
R shifting the automatic transmission out of
park position P
R Start 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. G
WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or 90
DoorsOpening and closing
Use one of the following options to stop the
closing process:
R Press the 0054button on the key.
R press the remote operating switch on the
driver's door.
R Press the closing or locking button on the
trunk lid.
R Pull the trunk lid handle. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is
a risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
i The opening dimensions of the trunk lid
can be found in the "Vehicle data" section
(Y page 429).
Opening You can open the trunk lid automatically
using the SmartKey or the handle in the trunk
lid.
X
Press and hold the 0054button on the
SmartKey until the trunk lid opens.
or
X If the trunk lid is unlocked, pull the trunk lid
handle and let it go again immediately. Closing X
To close: press closing button 0043in the
trunk lid.
Vehicles with trunk lid remote closing
feature and KEYLESS-GO: when all the
doors are closed, you can simultaneously
close the trunk lid and lock the vehicle. The
KEYLESS-GO key must be in the rear
detection range of the vehicle.
X Press locking button 0044in the trunk lid.
If KEYLESS-GO detects a SmartKey outside
the vehicle, the trunk lid closes and the
vehicle is locked.
i If KEYLESS-GO detects a SmartKey in the
trunk, the trunk lid opens again after it is
closed.
If KEYLESS-GO detects a second SmartKey
outside the vehicle, the trunk lid remains
closed. HANDS-FREE ACCESS
Important safety notes G
WARNING
The vehicle's exhaust system may be very hot.
You could burn yourself by touching the
exhaust system if you use HANDS-FREE
ACCESS. There is a risk of injury. Always
ensure that you only make the kicking
movement within the detection range of
sensors. Trunk
95Opening and closing Z