
Important safety notes
If you fail to adapt your driving style or if you
are inattentive, the driving safety systems can
neither reduce the risk of accident nor over-
ride the laws of physics. Driving safety sys-
tems are merely aids designed to assist driv-
ing. You are responsible for the distance to
the vehicle in front, for vehicle speed and for
braking in good time. Always adapt your driv-
ing style to suit the prevailing road, weather
and traffic conditions and maintain a safe dis-
tance from the vehicle in front. Drive care-
fully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tyres and
the road surface. Pay particular attention
to the information regarding tyres, recom-
mended minimum tyre tread depths etc. in
the "Wheels and tyres" section
( Y page 316).
In wintry driving conditions, always use
winter tyres (M+S tyres) and, if necessary,
snow chains. Only in this way will the driv-
ing safety systems described in this section
work as effectively as possible.
ABS (Anti-lock Braking System)
General notes
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi-
cle when braking.
The ! 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" sec-
tion for driving safety systems
( Y page 64).
GWARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid-
ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp ( Y page 256) and
display messages which may be shown in the
instrument cluster ( Y page 227).
ABS works from a speed of about
8 km/hupwards, regardless of road-surface
conditions. ABS works on slippery surfaces,
even when you only brake gently.
Braking
XIf ABS intervenes: continue to depress the
brake pedal with force until the braking sit-
uation is over.XTo 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 indica-
tion of hazardous road conditions, and func-
tions as a reminder to take extra care while
driving.
BAS (Brake Assist)
General notes
BAS operates in emergency braking situa-
tions. If you depress the brake pedal quickly,
BAS automatically boosts the braking force,
thus shortening the stopping distance.
64Driving safety systemsSafety

XBrake immediately in order to increase the
distance from the vehicle in front.
or
XTake evasive action provided it is safe to do
so.
For the distance warning function to assist
you when driving, the function must be acti-
vated in the on-board computer and be opera-
tional ( Y page 218).
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause the system to display a
warning.
With the help of the radar sensor system, the
distance warning function can detect obsta-
cles that are in the path of your vehicle for an
extended period of time.
From a speed of around 70 km/h, the dis-
tance warning function can also react to sta-
tionary obstacles, such as stopped or parked
vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision,
the system will alert you both visually and
acoustically.
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or the sensors are
obscured
R snow or heavy rain
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
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle.
Adaptive Brake Assist
i Observe the "Important safety notes" sec-
tion for driving safety systems
( Y page 64).
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions. In these cases, Adaptive Brake Assist
may not intervene. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
GWARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, 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 condi-
tions may also cause Brake Assist to inter-
vene.
Adaptive Brake Assist aids you in braking dur-
ing hazardous situations at speeds above
7 km/h and uses the radar sensor system to
evaluate the traffic situation.
With the help of a sensor system, adaptive
Brake Assist can detect obstacles that are in
the path of your vehicle for an extended
period of time.
Should you approach an obstacle and adap-
tive Brake Assist has detected a risk of colli-
sion, adaptive Brake Assist calculates the
braking force necessary to avoid a collision.
Should you apply the brakes forcefully, adap-
tive Brake Assist will automatically increase
66Driving safety systemsSafety

the braking force to a level suitable for the
traffic conditions.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:
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.
Vehicles with PRE-SAFE ®
: if adaptive Brake
Assist requires particularly high brake pres-
sure, preventive passenger protection meas-
ures (PRE-SAFE ®
) are deployed simultane-
ously.
Up to vehicle speeds of around 250 km/h,
adaptive Brake Assist is capable of reacting
to moving objects that have already been rec-
ognised as such at least once over the period
of observation. Adaptive Brake Assist does
not react to stationary obstacles.
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.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or the sensors are
obscured
R snow or heavy rain
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
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle.
COLLISION PREVENTION ASSIST PLUS
General notes
COLLISION PREVENTION ASSIST PLUS is
only available on vehicles with DISTRONIC.
COLLISION PREVENTION ASSIST PLUS
extends the functionality of COLLISION PRE-
VENTION ASSIST with an automatic braking
function. COLLISION PREVENTION ASSIST
PLUS can help you to minimise the risk of a
front-end collision with a vehicle ahead or
reduce the effects of such a collision. If COL-
LISION PREVENTION ASSIST PLUS detects
that there is a risk of a collision, you will be
warned visually and acoustically. In critical
situations COLLISION PREVENTION ASSIST
PLUS also initiates automatic braking.
Function
XTo activate/deactivate: activate or deac-
tivate COLLISION PREVENTION ASSIST
PLUS in the on-board computer
( Y page 218).
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the æ symbol appears in the
assistance graphics display.
If the driver's seat belt is fastened, COLLI-
SION PREVENTION ASSIST PLUS can brake
automatically within a speed range of
between 7 km/h and 200 km/h.
COLLISION PREVENTION ASSIST PLUS can
also react to stationary obstacles with auto-
matic braking within a speed range of
between 7 km/h and 30 km/h.
Vehicles with PRE-SAFE ®
: if the automatic
braking function of COLLISION PREVENTION
ASSIST PLUS intervenes powerfully, preven-
tive passenger protection measures (PRE-
SAFE ®
) are deployed simultaneously.
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or the sensors are
obscured
R snow or heavy rain
R interference by other radar sources
Driving safety systems67SafetyZ

Problems with the side windowsGWARNING
If you close a side window again immediately
after it has been blocked or reset, the side
window closes with increased or maximum
force. The reversing function is then not
active. Parts of the body could be trapped in
the closing area in the process. This poses an
increased risk of injury or even fatal injury.
Make sure that no parts of the body are in the
closing area. To stop the closing process,
release the switch or push the switch again to
reopen the side window.
Problem: a side window cannot be closed
because it is blocked by objects, e.g.
leaves in the window guide.
XRemove the objects.XClose the side window.
Problem: a side window cannot be closed
and you cannot see the cause. If a side
window is obstructed during closing and
reopens again slightly:
XImmediately after the window blocks, pull
the corresponding switch again until the
side window has closed.
The side window is closed with increased
force.
If a side window is obstructed again during
closing and reopens again slightly:
XImmediately after the window blocks, pull
the corresponding switch again until the
side window has closed.
The side window is closed without the anti-
entrapment feature.
Panorama sliding sunroof
Important safety notes
In the following section, the term "sliding sun-
roof" refers to the panorama sliding sunroof.
GWARNING
While opening and closing the sliding sunroof,
body parts in close proximity could become
trapped. There is a risk of injury.
Make sure that no body parts are in close
proximity during the opening and closing pro-
cedures.
If somebody becomes trapped:
R release the switch immediately, or
R during automatic operation, push the
switch briefly in any direction
The opening or closing procedure will be stop-
ped.
GWARNING
If children operate the sliding sunroof they
could become trapped, particularly if they are
left unsupervised. There is a risk of injury.
When leaving the vehicle, always take the key
with you and lock the vehicle. Never leave
children unattended in the vehicle.
GWARNING
At high speeds the raised sliding sunroof auto-
matically lowers slightly at the rear. This could
trap you or other persons. There is a risk of
injury. Make sure that nobody reaches into
the sweep of the sliding sunroof whilst the
vehicle is in motion.
If somebody becomes trapped, reduce speed
immediately, paying attention to road and
traffic conditions. The sliding sunroof opens
again to its original position.
If the sliding sunroof is not completely raised,
you can then raise it further with the switch.
! Only open the panorama sliding sunroof
if it is free of snow and ice. Otherwise, mal-
functions may occur.
Do not allow anything to protrude from the
sliding sunroof. Otherwise, the seals could
be damaged.
i Resonance noises can occur in addition
to the usual airflow noises when the sliding
sunroof is open. They are caused by minor
Panorama sliding sunroof89Opening and closingZ

Hazard warning lamps
The hazard warning lamps switch on auto-
matically if:
R an airbag is deployed or
R the vehicle decelerates rapidly from a
speed of more than 70 km/h and comes to
a standstill
XTo switch on the hazard warning lamps:
press button :.
All turn signals flash. If you now switch on
a turn signal using the combination switch,
only the turn signal lamp on the corre-
sponding side of the vehicle will flash.XTo switch off the hazard warning
lamps: press button :.
The hazard warning lamps switch off auto-
matically if the vehicle reaches a speed of
over 10 km/h again after a full brake appli-
cation.
i The hazard warning lamps still operate if
the ignition is switched off.
Headlamp cleaning system
If the "Wipe with washer fluid" function is
operated five times ( Y page 118) while the
lights are on and the engine is running, the
headlamps are cleaned automatically. When
you switch off the ignition, the automatic
headlamp cleaning system is reset and count-
ing is resumed from 0.
Intelligent Light System
General notes
The Intelligent Light System is a system that
adjusts the headlamps automatically to suit
the prevailing driving and weather conditions.
It offers advanced functions for improved illu-
mination of the road surface, e.g. depending
on the vehicle speed or weather conditions.
The system includes the active light function,
cornering light function, motorway mode and
extended range foglamps. The system is only
active when it is dark.
You can activate or deactivate the "Intelligent
Light System" using the on-board computer
( Y page 221).
Active light function
The active light function is a system that
moves the headlamps according to the steer-
ing movements of the front wheels. In this
way, relevant areas remain illuminated while
driving. This allows you to recognise pedes-
trians, cyclists and animals.
Active: when the lights are switched on.
110Exterior lightingLights and windscreen wipers

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos-
sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: ( Y page 24).
Overview of climate control systems
Important safety notes
Observe the settings recommended on the
following pages. The windows could other-
wise mist up.
To prevent the windows from misting up:
R switch off climate control only briefly
R switch on air-recirculation mode only
briefly
R switch on the cooling with air dehumidifi-
cation function
R switch on the defrost windscreen function
briefly, if required
THERMATIC automatic climate control/
THERMOTRONIC automatic climate control
regulates the temperature and the humidity
of the vehicle interior and filters out undesir-
able substances from the air.
THERMATIC automatic climate control/
THERMOTRONIC automatic climate control is
only operational when the engine is running.
Optimum operation is only achieved with the
side windows and panorama sliding sunroof
closed.
The residual heat function can only be acti-
vated or deactivated with the ignition
switched off ( Y page 135).
i Ventilate the vehicle for a brief period
during warm weather, e.g. using the con-
venience opening feature (Y page 88). This
will speed up the cooling process and the
desired vehicle interior temperature will be
reached more quickly.
i The integrated filter filters out most par-
ticles of dust and soot and completely fil-
ters out pollen. With THERMOTRONIC auto-
matic climate control, gaseous pollutants
and odours will also be reduced. A clogged
filter reduces the amount of air supplied to
the vehicle interior. For this reason, you
should always observe the interval for
replacing the filter, which is specified in the
Service Booklet. As it depends on environ-
mental conditions, e.g. heavy air pollution,
the interval may be shorter than stated in
the Service Booklet.
i It is possible that the residual heat func-
tion may be activated automatically an hour
after the key has been removed in order to
dry the air-conditioning system. The vehicle
is then ventilated for 30 minutes.124Overview of climate control systemsClimate control

Control panel for THERMATIC automatic climate control:To set the temperature (Y page 130);To demist the windscreen ( Y page 132)=To set the air distribution ( Y page 131)?To activate/deactivate air-recirculation mode ( Y page 134)ATo set the airflow ( Y page 131)BTo activate/deactivate cooling with air dehumidification ( Y page 128)CTo switch the rear window heating on/off ( Y page 133)Notes on using THERMATIC automatic
climate control
Automatic climate control
The following contains notes and recommen-
dations on optimum use of THERMATIC auto-
matic climate control.
R Switch on the air-conditioning system by
turning control knob A clockwise to the
desired position (except position 0).
R Set the temperature to 22 †.
R Recommendation to avoid misting of
the windows in the event of low outside
temperatures or rain: switch on the air
distribution ¯ and if possible switch off
P and O (Y page 131).
Deactivate air-recirculation mode
e (Y page 134).
Set airflow control A to a setting between
3 and 6(Y page 131).
R Recommendation for rapid cooling or
heating of the vehicle interior: briefly set
airflow control A to a setting between 3
and 6(Y page 131).
R Recommendation for a constant vehi-
cle interior temperature: set airflow con-
trol A to a setting between 1 and
3 (Y page 131).
R Recommendation for air distribution in
winter: select the O and ¯ settings
( Y page 131).
Recommendation for air distribution in
summer: select the P or P and
¯ settings ( Y page 131).
R Only use the "Windscreen demisting" func-
tion briefly until the windscreen is clear
again.Overview of climate control systems125Climate control

Auxiliary heating
Important safety notesGDANGER
If the exhaust pipe is blocked or sufficient
ventilation is not possible, toxic exhaust
fumes can enter the vehicle, especially car-
bon monoxide. This is the case, e.g. in
enclosed spaces, or if the vehicle is stuck in
snow. There is a risk of fatal injuries.
You should switch off the auxiliary heating in
enclosed spaces which do not have an extrac-
tion system, e.g. a garage. If the vehicle is
stuck in snow and you must leave the auxiliary
heating running, keep the exhaust pipe and
the area around the vehicle clear of snow. To
guarantee a sufficient supply of fresh air, open
a window on the side of the vehicle away from
the wind.
GWARNING
When the auxiliary heating is switched on,
parts of the vehicle can become very hot.
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system for extended
periods. There is a risk of fire.
When the auxiliary heating is switched on,
make sure that no flammable material can
come into contact with hot vehicle compo-
nents.
! Operating the auxiliary heating/ventila-
tion draws on the vehicle battery. After you
have heated or ventilated the vehicle a
maximum of two times, drive for a longer
distance.
i Switch the auxiliary heating on regularly
once a month for about ten minutes.
The auxiliary heating heats the air in the vehi-
cle interior to the set temperature. This
occurs without using the heat of the running
engine. The auxiliary heating is operated
directly using the vehicle's fuel. For this rea-
son, the fuel tank must be at least ¼ full to
ensure that the auxiliary heating functions.
The auxiliary heating/ventilation automati-
cally adjusts to changes in temperature and
weather conditions. For this reason, the aux-
iliary heating could switch from ventilation
mode to heating mode or from heating mode
to ventilation mode.
The auxiliary heating switches off when the
engine is switched off. The auxiliary ventila-
tion switches off when you turn the key to key
position 2(Y page 145).
The auxiliary heating switches off automati-
cally after 30 minutes.
You cannot use the auxiliary ventilation to
cool the vehicle interior to a temperature
lower than the outside temperature.
Before switching onXTurn the key to position 2 in the ignition
lock ( Y page 145).XSet the desired temperature.
Auxiliary heating or ventilation can also be
switched on if the manually set climate con-
trol is activated. Optimum comfort can be
attained when the system is set to automatic
mode. Set the temperature to 22 †.
The auxiliary heating/ventilation can be acti-
vated or deactivated using the remote control
or the button on the centre console.
The on-board computer can be used to spec-
ify up to three departure times, one of which
may be preselected ( Y page 224).
136Operating the climate control systemClimate control