
operation is possible using the switches in
the rear compartment. Driving safety systems
Overview of driving safety systems
In this section, you will find information about
the following driving safety systems:
R ABS (Anti-lock BrakingSystem)
R BAS (Brake AssistSystem)
R BAS PLUS ( BrakeAssist System Plus)
R ESP ®
(Electronic StabilityProgram)
R EBD ( Electronic Brake force Distribution)
R ADAPTIVE BRAKE
R PRE-SAFE ®
Brake Important safety notes
If you fail to adapt your driving style or
become distracted, the driving safety
systems can neither reduce the risk of
accident nor override the laws of physics.
Driving safety systems are merely aids
designed to assist driving. You are
responsible for the distance to the vehicle in
front, for vehicle speed and for braking in
good time. Always adapt your driving style to
suit the prevailing road, weather and traffic
conditions and maintain asafe distance from
the vehicle in front. Drive carefully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tires and
the road surface. Please pay special
attention to the note son tires,
recommended minimu mtire tread depths,
etc. (Y page 314).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary,
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 AB
Sr egulates 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 yellow 0018ABS 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 65). 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 ABSi s malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp (Y page 250) and
display messages which may be shown in the
instrument cluster (Y page 223).
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface
conditions. ABS works on slippery surfaces,
even if 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. Driving safety systems
65Safety Z

In the event of snowfall or heavy rain, the
recognition can be impaired.
Recognitio nby the rada rsensor system is
also impaired in the event of:
R dirt on the sensors or anything else
covering the sensors
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 fron tonadifferent line
relative to the center of your vehicle
Following damage to the fron tend of the
vehicle, have the configuratio nand operation
of the rada rsensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the fron tofthe vehicle.
Function X
To activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer (Y page 214).
If the PRE-SAFE ®
Brake is not activated, the
0001 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
intermitten twarning tone will then sound and
the 000A distance warning lamp will light up
in the instrument cluster.
X Brake immediately to defuse the situation.
or
X Take evasive action provide ditis safe to do
so.
PRE-SAFE ®
Brake can also brake the vehicle
automatically under the following conditions:
R the driver and front-passenger have their
seat belts fastened and
R the vehicle speed is between
approximately 4mph (7 km/h) and
124 mph (200 km/h)
At speeds of up to approximately 40 mph
(70 km/ h)PRE-SAFE ®
Brake can also detect
stationary objects. Examples of stationary
objects are stopped or parked vehicles.
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 any danger of a rear-end
collision.
R there is no longer an obstacle detected in
front of your 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. 72
Theft deterrent locking systemSafety

vehicle. Never leave children unsupervised in
the vehicle. 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. Side window reversing feature
The side windows are equipped with an
automatic reversing feature. If a solid object
blocks or restricts a side window during the
closing process, the side window opens again
automatically.H owever, the automatic
reversing feature is only an aid and does not
relieve you of the responsibility of paying
attention when closing a side window. G
WARNING
The reversing feature does not react:
R to soft, light and thin objects, e.g. small
fingers
R over the last 1/6 in(4 mm) of the closing
movement
R during resetting
R when closing the side window again
manually immediately after automatic
reversing This means that the reversing feature cannot
prevent someone being trapped in these
situations. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure. If
someone becomes trapped, press the switch
to open the side window again.
Opening and closing the side
windows
0002
Front left
0003 Front right
0022 Rear right
0021 Rear left
The switches for all side windows are located
on the driver's door. There is also a switch on
each door for the corresponding side window.
The switches on the driver's door take
precedence.
i The side windows cannot be operated
from the rear when the override feature for
the side windows is activated (Y page 64).
X Turn the SmartKey to position 1or 2in the
ignition lock.
X To open: press the corresponding switch.
X To close: pull the corresponding switch.
i If you press the switch beyond the point
of resistance, an automatic opening/
closing process is started in the
corresponding direction .You can stop
automatic operation by operating the
switch again. 88
Side windowsOpening and closing

KEYLESS-GO
General notes
R
Do not keep the KEYLESS-GO key:
-with electronic devices, e.g. a mobile
phone or another SmartKey
- with metallic objects, e.g. coins or metal
foil
- inside metallic objects, e.g. a metal case
This can impair the functionality of the
KEYLESS-GO key.
Vehicles with KEYLESS-GO are equipped with
aS martKey featuring an integrated KEYLESS-
GO function and a detachable Start/Stop
button.
The Start/Stop button must be inserted in the
ignitio nlock and the SmartKey must be in the
vehicle.
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
immediately.
The Start/Stop button can be removed from
the ignition lock. Then, you can insert the
SmartKey into the ignition lock.
i 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 vehicle. The vehicle can be
started with the Start/Stop button if the
SmartKey is in the vehicle. 0002
Start/Stop button
0003 Ignition lock
X Insert Start/Stop button 0002into ignition
lock 0003.
i When you insert Start/Stop button 0002
into ignition lock 0003, the system needs
approximately 2seconds recognition time.
You can then use Start/Stop button 0002. Start/Stop button
0022
USA only
0021 Canada only
X Position 0: if Start/Stop button 0002has not
yet been pressed, this corresponds to the
key being removed from the ignition.
X Position 1: press Start/Stop button 0002.
You can now activate the windshield
wipers, for example.
i If you then open the driver's door when in
this position, the power supply is
deactivated.
X Position 2: (ignition): press Start/Stop
button 0002twice. 148
DrivingDriving and parking

Problem Possible causes/consequences and
0001 Solutions
The engine is not
running smoothly and
is misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it. The coolant
temperature gauge
shows a value above
248 ‡ (120 †). The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X
Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 290). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
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. G
WARNING
The automatic transmission switches to
neutral position Nwhen you switch off the
engine. The vehicle may roll away.T here is a
risk of an accident.
After switching off the engine, always switch
to parking position P. Prevent the parked
vehicle from rolling away by applying the
parking brake. Selector lever
Overview of transmission positions Example: selector lever
0011
Park position with selector lever lock
000E Reverse gear
000F Neutral
0010 Drive 154
Automatic transmissionDriving and parking

Problems with the transmission
Problem Possible causes/consequences and
0001 Solutions
The transmission has
problems shifting gear. The transmission is losing oil.
X
Have the transmission checked at a qualified specialist
workshop immediately. The acceleration ability
is deteriorating.
The transmission no
longer changes gear. The transmission is in emergency mode.
It is only possible to shift into
secondgear and reverse gear.
X Stop the vehicle.
X Shift the transmission to position P.
X Switch off the engine.
X Wait at least ten seconds before restarting the engine.
X Shift the transmission to position Dor R.
If D is selected, the transmission shifts into secondgear; ifRis
selected, the transmission shifts into reverse gear.
X Have the transmission checked at a qualified specialist
workshop immediately. Releasing the parking lock manually
In the event of an electrical malfunction, it is
possible to release the selector lever lock
manually to move it out of position P.This is
the case, for example, if you wish to tow the
vehicle away. !
Do not use any sharp-edged objects to
remove the selector lever gaiter from the
center console. This could damage the
selector lever gaiter.
X Apply the parking brake.
X Pry off selector lever gaiter 0002with a flat,
blunt object (e.g. a screwdriver wrapped in cloth) from the right-hand edge. Pull
selector lever gaiter
0002up and out.
X Press release button 0003down and
simultaneously move the selector lever out
of position P.
The selector lever can now be moved freely
until it is returned to position P. Transfer case
This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always
transmitted to both axles.
! Performance tests may only be carried
out on a 2-axle dynamometer. The brake
system or transfer case could otherwise be
damaged. Contact a qualified specialist
workshop for a performance test.
! If the parking brake is being tested on a
brake dynamometer, the ignition must be
switched off (SmartKey or Start/Stop
button in position 0or 1), as ESP ®
will Automatic transmission
161Driving and parking Z

otherwise automatically intervene. The
brake system could otherwise be damaged.
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission. Refueling
Important safety notes
G
WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and
explosion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before
refueling. G
WARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury.
You must make sure that fuel does not come
into contact with your skin, eyes or clothing
and that it is not swallowed. Do not inhale fuel
vapors. Keep fuel away from children.
If you or others come into contact with fuel,
observe the following:
R Wash away fuel from skin immediately
using soap and water.
R If fuel comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical assistance
without delay.
R If fuel is swallowed, seek medical
assistance without delay. Do not induce
vomiting.
R Immediately change out of clothing which
has come into contact with fuel. G
WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion. Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
! Overfilling the fuel tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
Do not get into the vehicle again during the
refueling process. Otherwise, electrostatic
charge could build up again.
If you overfill the fuel tank, fuel could spray
out when the fuel pump nozzle is removed.
For further information on fuel and fuel quality
(Y page 351). Refueling
Opening/closing the fuel filler flap 0002
To open the fuel filler flap
0003 To insert the fuel filler cap
0022 Tire pressure table
0021 Fuel type to be used
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or with KEYLESS-
GO. 162
RefuelingDriving and parking

Problems with fuel and the fuel tank
Problem Possible causes/consequences and
0001 Solutions
Fuel is leaking from the
vehicle. The fuel line or the fuel tank is faulty.
G WARNING
Risk of explosion or fire.
X Turn the SmartKey to position 0in the ignition lock and remove
it immediately (Y page 147).
X Do not restart the engine under any circumstances.
X Consult a qualified specialist workshop. The fuel filler flap
cannot be opened. The fuel filler flap is not unlocked.
or
The SmartKey battery is discharged.
X
Unlock the vehicle using the mechanical key (Y page 78).
X Open the trunk lid.
X Manually unlock the fuel filler flap using the emergency release
(Y page 163). The fuel filler flap is unlocked, but the opening mechanism is
jammed.
X
Consult a qualified specialist workshop. Parking
Important safety notes
G
WARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable
materials come into contact with parts of the
vehicle which are hot. Take particular care not
to park on dry grassland or harvested grain
fields. G
WARNING
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.Y
ou will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving. G
WARNING
If you leave children unsupervised in the
vehicle, they could set it in motion by, for
example:
R release the parking brake.
R shift the automatic transmission out of the
parking position P.
R start the engine.
In addition, they may operate vehicle
equipment 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. 164
ParkingDriving and parking