
Distance warning function
General notes
The distance warning function can help you to
minimise the risk of a collision with the vehicle in front or reduce the effects of such a collision. If
the distance warning function detects that there
is a risk of a collision, you will be warned visually and acoustically.
Important safety notes i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 61).G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation; do not rely on the distance warning
function alone.
Function The distance warning function issues a warning at speeds:
R of approximately 30 km/h or more, if, over
several seconds, the distance maintained to
the vehicle travelling in front is insufficient. The
· distance warning lamp then lights
up in the instrument cluster.
R of approximately 7 km/h or more, if you rap-
idly approach a vehicle in front. An intermit-
tent warning tone will then sound and the
· distance warning lamp will light up in the
instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the system to display a warning.
With the help of the radar sensor system, the
distance warning function can detect obstacles
that are in the path of your vehicle for an exten-
ded period of time.
Up to a speed of approximately 70 km/h, the
distance warning function can also react to sta-
tionary obstacles, such as stopped or parked
vehicles.
Autonomous braking function If the driver does not react to the distance warn-
ing signal in a critical situation, COLLISION PRE- VENTION ASSIST PLUS can assist with the
autonomous braking function.
The autonomous braking function:
R gives the driver more time to react to critical
driving situations
R can help the driver to avoid an accident or
R reduces the effects of an accident
The autonomous braking function is available in
the following speed ranges:
R from 7 km/h to approximately 105 km/h for
moving objects
R from 7 km/h to approximately 50 km/h for
stationary objects
Due to the nature of the system, complicated
but non-critical driving conditions may also
cause the autonomous braking function to inter- vene.
If the autonomous braking function demands
particularly high braking force, preventative
passenger protection measures (PRE-SAFE ®
)
are activated simultaneously. Driving safety syste
ms
65Safety Z 

Adaptive Brake Assist
General notes
i Observe the "Important safety notes" sec-
tion (Y page 61).
With the help of Adaptive Brake Assist, the dis-
tance warning signal can detect obstacles that
are in the path of your vehicle for an extended
period of time.
If Adaptive Brake Assist detects a risk of a col-
lision 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
7 km/h. It uses radar sensor technology to
assess the traffic situation.
Up to a speed of approximately 250 km/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 obser-
vation.
Up to a speed of approximately 70 km/h, Adap-
tive Brake Assist reacts to stationary obstacles.
If Adaptive Brake Assist demands a particularly
high braking force, preventative passenger pro-
tection measures (PRE-SAFE ®
) are activated
simultaneously (Y page 47).
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if: R you release the brake pedal
R there is no longer any danger of a collision
R no obstacle is detected in front of your vehicle
Adaptive Brake Assist is then deactivated.
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 61).G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions. In such cases, Adaptive Brake Assist can:
R intervene unnecessarily
R not 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. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when 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. Adaptive brake lights
i Observe the "Important safety notes" sec-
tion (Y page 61).
The adaptive brake lights warn following traffic
in an emergency braking situation:
R by flashing brake lamps
R the hazard warning lamps are activated
If you brake sharply from a speed of more than
50 km/h or if braking is assisted by BAS or BAS
PLUS, the brake lamps flash rapidly. In this way,
traffic travelling behind you is warned in an even
more noticeable manner.
If you brake sharply from a speed of more than
70 km/h to a standstill, the hazard warning
lamps are activated automatically. If the brakes are applied again, the brake lamps light up con-
tinuously. The hazard warning lamps switch off
automatically if you travel faster than 10 km/h. 66
Driving safety systemsSafety 

EBD (electronic brake force distribu-
tion)
General notes EBD monitors and controls the brake pressure
on the rear wheels to improve driving stability
while braking.
Important safety notes i
Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 61).G
WARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases the risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps (Y page 256) as well as display
messages (Y page 231). ADAPTIVE BRAKE
i Observe the "Important safety notes" sec-
tion (Y page 61).
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 177) and hill start
assist (Y page 142). PRE-SAFE
®
Brake
General notes PRE-SAFE
®
Brake can help you to minimise the
risk of a collision with a vehicle ahead or a
pedestrian, and reduce the effects of such a
collision. If PRE-SAFE ®
Brake has detected a risk
of a collision, you will be warned visually and
acoustically as well as by automatic braking.
i Pay attention to the important safety notes
in the "Driving safety systems" section
(Y page 61). PRE
‑SAFE ®
Brake is only available in vehicles
with the Driving Assistance Plus package.
For PRE-SAFE ®
Brake to assist you when driving,
the radar sensor system and the camera system must be switched on and operational.
With the help of the radar sensor system and the
camera system, PRE-SAFE ®
Brake can detect
obstacles that are in front of your vehicle for an extended period of time.
In addition, pedestrians in the path of your vehi-
cle can be detected.
PRE-SAFE ®
Brake detects pedestrians using
typical characteristics such as the body con-
tours and posture of a person standing upright.
i Observe the restrictions described in the
"Important safety notes" section
(Y page 69).
Important safety notes G
WARNING
PRE-SAFE ®
Brake will initially brake your vehi-
cle by a partial application of the brakes if a
danger of collision is detected. There may be
a collision unless you brake yourself. Even
after subsequent full application of the brakes
a collision cannot always be avoided, partic-
ularly when approaching at too high a speed.
There is a risk of an accident.
Always apply the brakes yourself and try to
take evasive action, provided it is safe to do
so.
In the event of a partial application of the brakes, the vehicle is braked with up to 50% of the full
braking pressure. G
WARNING
PRE-SAFE ®
Brake cannot always clearly iden-
tify objects and complex traffic conditions.
In these cases, PRE-SAFE ®
Brake may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and be ready to brake, especially if Driving safety systems
69Safety
Z 

PRE-SAFE
®
Brake warns you. Terminate the
intervention in a non-critical driving situation. G
WARNING
PRE-SAFE ®
Brake cannot always clearly iden-
tify people, especially if they are moving. In
these cases, PRE-SAFE ®
Brake cannot inter-
vene. There is a risk of an accident.
Always pay particular attention to the traffic
situation and be ready to brake, especially if
PRE-SAFE ®
Brake warns you.
In order to maintain the appropriate distance to
the vehicle in front and thus prevent a collision, you must apply the brakes yourself. G
WARNING
PRE-SAFE ®
Brake does not react:
R to small people, e.g. children
R to animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, PRE-SAFE ®
Brake may neither
give warnings nor intervene in all critical sit-
uations. There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
In the event of snowfall or heavy rain, detection can be impaired.
Detection by the radar sensor system is also
impaired in the event of:
R dirt on the sensors or obscured sensors
R interference by other radar sources
R strong radar reflections, for example, in multi-
storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different line
Detection by the camera system is also impaired in the event of:
R dirt on the camera or if the camera is covered
R glare on the camera system, e.g. from the sun
being low in the sky R
darkness
R if:
- pedestrians move quickly, e.g. into the path
of the vehicle
- the camera system no longer detects a
pedestrian as a person due to special cloth-
ing or other objects
- a pedestrian is concealed by other objects
- the typical outline of a person is not distin-
guishable from the background
Following damage to the front end of the vehicle, have the radar sensor settings and operation
checked at a qualified specialist workshop. This
also applies to collisions at slow speeds where
there is no visible damage to the front of the
vehicle.
Following damage to the windscreen, have the
configuration and operation of the camera sys-
tem checked at a qualified specialist workshop.
Function X
To activate/deactivate: activate or deacti-
vate PRE-SAFE ®
Brake in the on-board com-
puter (Y page 221).
If the PRE-SAFE ®
Brake is not activated, the
æ symbol appears in the multifunction dis-
play.
This function will issue a warning if: R at a speed of approximately 30 km/ho r more
the distance maintained to the vehicle travel- ling in front is insufficient for several seconds
The · distance warning lamp then lights
up in the instrument cluster.
R at a speed of approximately 7 km/h or more,
you rapidly approach a vehicle in front
An intermittent warning tone will then sound
and the ·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.
The PRE-SAFE ®
Brake function can also brake
the vehicle automatically under the following
conditions:
R the driver and front passenger have their seat
belts fastened 70
Driving safety systemsSafety 

Key
Important safety notes
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the outside, the double lock function is activated as stand-
ard. It is then not possible to open the doors
from inside the vehicle. You can deactivate the
double lock function by deactivating the interior
motion sensor (Y page 73). The doors can then
be opened from the inside after the vehicle has
been locked from the outside. The anti-theft
alarm system is triggered if the door is opened
from the inside. Switch off the alarm
(Y page 71).
All countries: G
WARNING
If children are left unsupervised in the vehicle, they could:
R open doors, thereby endangering other per-
sons or road users
R get out and be struck by oncoming traffic
R operate vehicle equipment and become
trapped, for example
In addition, the children could also set the
vehicle in motion, for example, if they:
R release the parking brake
R shift the automatic transmission out of park
position P or shift manual transmission into
neutral
R start the engine
There is a risk of an accident and injury. When leaving the vehicle, always take the key
with you and lock the vehicle. Never leave
children and animals unattended in the vehi-
cle. Keep the keys out of the reach of children. G
WARNING
If you attach heavy or large objects to the key, the key 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
key. Remove any bulky keyrings before insert-
ing the key into the ignition lock.
! Keep the key away from strong magnetic
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 key: R with electronic devices, e.g. a mobile phone
or another key
R with metallic objects, e.g. coins or metal film
R inside metallic objects, e.g. a metal case
This can affect the key's functionality. Key functions
:
& Locks the vehicle
; F Unlocks the boot lid
= % Unlocks the vehicle
X To unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
R the vehicle locks again
R protection against theft is reactivated 74
KeyOpening and closing 

G
WARNING
If children are left unsupervised in the vehicle, they could:
R open doors, thereby endangering other per-
sons or road users
R get out and be struck by oncoming traffic
R operate vehicle equipment and become
trapped, for example
In addition, the children could also set the
vehicle in motion, for example, if they:
R release the parking brake
R shift the automatic transmission out of park
position P or shift manual transmission into
neutral
R start the engine
There is a risk of an accident and injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children and animals unattended in the vehi-
cle. Keep the keys out of the reach of children. Unlocking and opening the doors
from the inside
! The side windows will not open/close if the
battery is discharged or if the side windows
have iced up. It will then not be possible to
close the door. Do not attempt to force the
door to close. You could otherwise damage
the door or the side window.
For all countries except the United Kingdom: you can open a door from inside the vehicle evenif it has been locked.
If the vehicle has previously been locked from
the outside, opening a door from the inside will
trigger the anti-theft alarm system. Switch off
the alarm (Y page 71).
Only for the United Kingdom: if the vehicle
has been locked with the key from the outside,
the double lock function is activated as stand-
ard. It is then not possible to open the doors
from inside the vehicle. You can deactivate the
double lock function by deactivating the interior
motion sensor (Y page 72). The doors can then
be opened from the inside after the vehicle has
been locked from the outside. The anti-theft
alarm system is triggered if the door is opened from the inside. Switch off the alarm
(Y
page 71).
All countries: X
Pull door handle ;.
If the door is locked, locking knob :pops up.
The door is unlocked and can be opened.
When a door is opened, the side window on that
side opens slightly. When the door is closed, the
side window is raised again. Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle from
the inside. The switches are on the driver's door. X
To unlock: press button :.
X To lock: press button ;.
If all the doors are closed, the vehicle locks.
This does not lock or unlock the fuel filler flap.
If the vehicle has been locked from the outside,
it cannot be centrally unlocked from the inside.
For all countries except the United Kingdom:
you can open a door from inside the vehicle even if it has been locked.
United Kingdom only: you can only open a
door from inside the vehicle if the double-lock Doors
81Opening and closing Z 

Running-in notes
Important safety notes
In certain driving and driving safety systems, the sensors adjust automatically while a certain dis-
tance is being driven after the vehicle has been delivered or after repairs. Full system effective-
ness is not reached until the end of this teach-in process.
Brake pads/linings and discs that are either new or have been replaced only achieve optimum
braking effect after several hundred kilometres
of driving. Compensate for the reduced braking
effect by applying greater force to the brake
pedal. The first 1500 km
If you treat the engine with sufficient care from
the very start, you will be rewarded with excel-
lent performance for the remainder of the
engine's life.
R Drive at varying road speeds and engine
speeds for the first 1500 km.
R Avoid overstraining the vehicle during this
period, e.g. driving at full throttle.
R Change gear in good time, before the rev
counter needle is Ôof the way to the red area
of the rev counter.
R Do not shift down a gear manually in order to
brake.
R Vehicles with automatic transmission: try
to avoid depressing the accelerator pedal
beyond the point of resistance (kickdown).
After 1500 km, you may gradually accelerate
the vehicle to full road and engine speeds.
i You should also observe these notes on run-
ning-in if the engine or parts of the drive train on your vehicle have been replaced. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell may restrict
the clearance around the pedals or block a
depressed pedal. This jeopardises the oper- ating and road safety of the vehicle. There is a
risk of an accident.
Stow all objects securely in the vehicle so that
they do not get into the driver's footwell.
Always fit the floormats securely and as pre-
scribed in order to ensure that there is always sufficient room for the pedals. Do not use
loose floormats and do not place several floor-mats on top of one another. G
WARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. 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. 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. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose 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 when the vehicle
is stationary. Drive off immediately. Avoid
high engine speeds and driving at full throttle
until the engine has reached its operating
temperature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary. 138
DrivingDriving and parking 

i
The last speed stored is cleared when you
switch off the engine.
Permanent SPEEDTRONIC You can use the on-board computer to limit the
speed permanently to a value between
160 km/h( e.g. for driving on winter tyres) and
the maximum speed (Y page 225).
Shortly before the stored speed is reached, it
appears in the multifunction display.
Permanent SPEEDTRONIC remains active, even
if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed, even if you depress the accelerator pedal beyond the
pressure point (kickdown). DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and auto-
matically helps you maintain the distance to the vehicle detected in front. Vehicles are detected
with the aid of the radar sensor system.
DISTRONIC PLUS brakes automatically so that
the set speed is not exceeded.
Change into a lower gear in good time on long
and steep downhill gradients. Take particular
note of this when driving a laden vehicle. By
doing so, you will make use of the braking effect
of the engine. This relieves the load on the brake system and prevents the brakes from overheat- ing and wearing too quickly.
If DISTRONIC PLUS detects that there is a risk of
a collision, you will be warned visually and
acoustically. Without your intervention,
DISTRONIC PLUS cannot prevent a collision. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the
instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is safe
to do so.
For DISTRONIC PLUS to assist you, the radar
sensor system must be operational.
DISTRONIC PLUS operates in the range
between 0 km/h and 200 km/h.
Do not use DISTRONIC PLUS while driving on
roads with steep gradients. Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly rec-
ognise other road users and complex traffic
conditions.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be prepared to
brake, particularly if DISTRONIC PLUS warns
you. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this deceleration is not sufficient,
DISTRONIC PLUS alerts you with a visual and
acoustic warning. There is a risk of an acci-
dent.
Apply the brakes yourself in these situations
and try to take evasive action.
! When DISTRONIC PLUS or the HOLD func-
tion is activated, the vehicle brakes automat- ically in certain situations. 168
Driving systemsDriving an
d parking