
Notes on using THERMOTRONIC auto-
matic climate control
The following contains instructions and rec-
ommendations to enable you to get the most
out of your THERMOTRONIC automatic cli-
mate control.
R Activate climate control using the Ãand
¿ buttons. The indicator lamps in the
à and¿ buttons light up.
R In automatic mode, you can also use the
ñ button to set a climate mode
(FOCUS/MEDIUM/DIFFUSE). The
MEDIUM level is recommended.
R Set the temperature to 22 †.
R Only use the demisting function briefly until
the windscreen is clear again.
R Only use the air-recirculation mode briefly,
e.g. if there are unpleasant outside odours
or when in a tunnel. The windows could
otherwise mist up as no fresh air is drawn
into the vehicle in air-recirculation mode.
R Use the ZONE function to adopt the tem-
perature settings on the driver's side for
the front-passenger side and the rear com-
partment as well. The indicator lamp in the
á button goes out.
R Use the residual heat function if you want
to heat or ventilate the vehicle interior
when the ignition is switched off. The resid-
ual heat function can only be activated or
deactivated with the ignition switched off. Operating the climate control system
Switching climate control on/off
Points to observe before use i
If climate control is switched off, the air
supply and air circulation are also switched
off. Only use this setting for a brief period.
The windows could otherwise mist up.
i Switch on climate control primarily using
the à button ( Ypage 132). Switching on/off X
Turn the key to position 2in the ignition
lock.
X To switch on: press theÃbutton.
The indicator lamp in the Ãbutton lights
up. Airflow and air distribution are set to
automatic mode.
or
X Press the ^button.
The indicator lamp in the ^button goes
out. The previous settings are reactivated.
X To switch off: press the^button.
The indicator lamp in the ^button lights
up. Activating/deactivating the cooling
with air dehumidification function
Points to observe before use G
WARNING
If the "cooling with air dehumidification" func-
tion is deactivated, the air inside the vehicle
will not be cooled (during warm weather) or
dehumidified. The windows could mist up
more quickly. This may prevent you from
observing the traffic conditions, thereby caus-
ing an accident.
The cooling with air dehumidification function
is only available when the engine is running.
The air inside the vehicle is cooled and dehu-
midified according to the temperature selec-
ted.
Condensation may drip from the underside of
the vehicle when cooling mode is active. This
is normal and not a sign that there is a mal-
function.
i The cooling with air dehumidification
function uses refrigerant R134a. This
refrigerant does not contain chlorofluoro-
carbons, and therefore does not damage
the ozone layer. Operating the climate control system
131Climate control Z

Windows misted up on the outside
X
Activate the windscreen wipers.
X Press the _button repeatedly until the
O orP symbol appears in the dis-
play.
i You should only select this setting until
the windscreen is clear again. Rear window heating
Switching on/off G
WARNING
Clear all windows of ice or snow before setting
off. Otherwise, impaired visibility could
endanger you and others.
The rear window heating has a high current
draw. You should therefore switch it off as
soon as the window is clear. It otherwise
switches off automatically after several
minutes.
If the battery voltage is too low, the rear win-
dow heating may switch off.
X Turn the key to position 2in the ignition
lock.
X Press the ¤button.
The indicator lamp in the ¤button lights
up or goes out.
Problems with the rear window heating The rear window heating has switched off
prematurely or cannot be activated.
X
Switch off any consumers that are not
required, e.g. reading lamps or interior
lighting.
When the battery is sufficiently charged,
the rear window heating is activated again
automatically. Activating/deactivating air-recircula-
tion mode
You can deactivate the flow of fresh air if
unpleasant odours are entering the vehicle
from outside. The air already inside the vehi-
cle will then be recirculated.
The operation of air-recirculation mode is the
same for all control panels. G
WARNING
Only switch over to air-recirculation mode
briefly at low outside temperatures. Other-
wise, the windows could mist up, thus impair-
ing visibility and endangering yourself and
others. This may prevent you from observing
the traffic conditions, thereby causing an
accident.
X Turn the key to position 2in the ignition
lock.
X To activate: press thegbutton.
The indicator lamp in the gbutton lights
up.
i In the event of high pollution levels 11
or at
high outside temperatures, air-recircula-
tion mode is automatically activated. When
air-recirculation mode is activated auto-
matically, the indicator lamp in the g
button is not lit.
Outside air is added after about
30 minutes.
X To deactivate: press thegbutton.
The indicator lamp in the gbutton goes
out.
11 THERMOTRONIC automatic climate control only. Operating the climate control system
135Climate control Z

Auxiliary heating
Important safety notes G
WARNING
Exhaust fumes are produced when the auxili-
ary heating is in operation. Inhaling these
exhaust fumes can be poisonous. You should
therefore switch off the auxiliary heating in
confined spaces without an extraction sys-
tem, e.g. a garage. G
WARNING
When operating the auxiliary heating parts of
the vehicle can get very hot. Make sure that
the exhaust system does not under any cir-
cumstances come into contact with easily
ignitable material such as dry grass or fuels.
The material could otherwise ignite and set
the vehicle alight. Choose your parking spot
accordingly.
Operating the auxiliary heating is thus pro-
hibited at filling stations or when your vehicle
is being refuelled. You must therefore switch
off the auxiliary heating at filling stations.
! 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
passenger compartment to the selected tem-
perature. It does not use the heat of the run-
ning engine to do this. The auxiliary heating
is operated directly using the vehicle's fuel.
For this reason, the tank content must be at
least at reserve fuel level 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 automati-
cally after 50 minutes. This time limit can be
altered. To do this, visit a qualified specialist
workshop.
You cannot use the auxiliary ventilation to
cool the vehicle interior to a temperature
lower than the outside temperature.
Before switching on
X
Turn the key to position 2in the ignition
lock.
X Set the temperature.
The auxiliary heating/ventilation can be acti-
vated even when climate control is set to
manual. 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 242).
Switching the auxiliary heating/venti-
lation on/off using the centre console
button Switch in the centre consoleOperating the climate control system
137Climate control Z

Activating
X
Press button :.
Indicator lamp ;lights up. If all conditions
for automatic engine switch-off
(Y page 151) are fulfilled, the ¤symbol
is shown in green in the multifunction dis-
play.
If not all conditions for automatic engine
switch-off are fulfilled, the
(Y page 151) ¤symbol is shown in yel-
low in the multifunction display. If this is the
case, the ECO start/stop function is not
available.
i If indicator lamp ;is off, the ECO start/
stop function has been deactivated man-
ually or as the result of a malfunction. The
engine will then not be switched off auto-
matically when the vehicle stops.
i The ECO start/stop function is activated
each time the engine is switched on.
Automatic engine switch-off The ECO start/stop function is operational
and the ¤symbol is displayed in green in
the multifunction display if:
R the indicator lamp in the ECO button is lit
green..
R the vehicle is stationary
R the outside temperature is within the com-
fort range.
R the engine is at normal operating temper-
ature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windscreen is
not misted up when the air-conditioning
system is switched on.
R the bonnet is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
If not all conditions for automatic engine
switch-off (Y page 151) are fulfilled, the ¤
symbol is shown in yellow in the multi-
function display.
i The engine can be switched off automat-
ically a maximum of four times (initial stop,
then three subsequent stops) in succes-
sion. The ¤symbol is shown in yellow
in the multifunction display after the engine
has been started automatically for the
fourth time. When the ¤symbol is
shown in green in the multifunction display,
automatic engine switch-off is again possi-
ble.
i During automatic engine switch-off, the
climate control system only operates at a
reduced capacity. If you require full climate
control capacity, the ECO start/stop func-
tion can be deactivated by pressing the
ECO button (Y page 150).
Vehicles with manual transmission The ECO start/stop function switches off the
engine automatically at low speeds.
X
Brake the vehicle until it comes to a stand-
still.
X Engage neutral N(Ypage 154) (follow
gearshift instruction :to engage neutral
N, if necessary).
X Release the clutch pedal.
The engine is switched off automatically.
Vehicles with automatic transmission
The ECO start/stop function switches the
engine off automatically if the vehicle is
braked to a standstill and the brake remains Driving
151Driving and pa rking Z

depressed with the transmission in position
D or N.
i If you shift the transmission from Rto D,
the ECO start/stop function is available
again once the ¤symbol reappears in
green in the multifunction display.
i You can also activate the HOLD function
when the vehicle is stationary if the engine
has been switched off automatically. It is
then not necessary to continue applying
the brakes during the automatic stop
phase. When you depress the accelerator
pedal, the engine starts automatically and
the braking effect of the HOLD function is
deactivated. Depress the accelerator pedal
gently, as the engine must be started first.
Automatic engine start The engine is started automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button
R you unfasten your seat belt or open the
driver's door
R the vehicle starts to roll
R the brake system requires this
R the temperature in the vehicle interior devi-
ates from the set range
R the system detects moisture on the wind-
screen when the air-conditioning system is
switched on
R the battery's charge status is too low
Vehicles with manual transmission
The engine is started automatically if:
R you depress the clutch pedal
R you depress the accelerator pedal
! Only engage gear when the clutch pedal
is depressed. Vehicles with automatic transmission
The engine is started automatically if:
R
you release the brakes when in transmis-
sion position Dor N
R you depress the accelerator pedal
R you engage reverse gear R
R you move the transmission out of position
P
i Shifting the transmission to position P
does not start the engine.
i If you shift the transmission from Rto D,
the ECO start/stop function is available
again as soon as the ¤symbol reap-
pears in the multifunction display. 152
DrivingDriving and parking

i
The ECO display summarises the driving
characteristics from the start of the journey
to its completion. Therefore, there are
dynamic changes in the bars at the start of
a journey. During a prolonged driving time,
these changes are smaller. For dynamic
changes, perform a manual reset.
For further information on the ECO display,
see (Y page 231). Short journeys
! Vehicles with a diesel particle filter: if
the vehicle is mostly driven for short dis-
tances, it is possible that malfunctions may
occur during the automatic cleaning of the
diesel particle filter. This may lead to fuel
collecting in the engine oil and cause
engine failure. Therefore, if you frequently
drive short distances, you should take a 20
minute trip on a motorway or rural road at
least every 500km. Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients On long and steep downhill gradients, you
must select shift range
1,2or 3in good time.
Take particular note of this when driving a
laden vehicle and when towing a trailer.
i This also applies if you have activated
cruise control or SPEEDTRONIC. This will use the braking effect of the engine,
so less braking will be required to prevent the
vehicle from gaining speed. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
Heavy and light loads
G
WARNING
The braking system can overheat if you leave
your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There
is a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately.
Drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
If the brakes have been used only moderately,
you should occasionally test their effective-
ness. To do this, brake more firmly from a
higher speed. This improves the grip of the
brakes.
Wet road surfaces If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm
up the brake discs, thereby drying them more Driving tips
167Driving and parking Z

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 241).
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
Important safety notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. DIS-
TRONIC PLUS brakes automatically so that
the set speed is not exceeded.
On long and steep downhill gradients, espe-
cially if the vehicle is laden or towing a trailer,
you must select shift range 1,2or 3in good
time. 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 overheating and wearing too
quickly.
If DISTRONIC PLUS detects a slower-moving
vehicle in front, your vehicle is braked in order
to maintain the preset distance to the vehicle
in front. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. G
WARNING
DISTRONIC PLUS is only an aid designed to
assist driving. The driver remains fully respon-
sible for the vehicle's distance from other vehicles, the vehicle's speed and for braking
in good time.
DISTRONIC PLUS does not react in particular
to:
R pedestrians
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
DISTRONIC PLUS may not detect narrow vehi-
cles driving in front, e.g. motorcycles, or vehi-
cles driving on a different line. Therefore,
always pay attention to traffic conditions even
when DISTRONIC PLUS is activated. Other-
wise, you may fail to recognise dangers in
time, cause an accident and injure yourself
and others. G
WARNING
DISTRONIC PLUS cannot take account of road
and traffic conditions. If DISTRONIC does not
recognise or no longer recognises the vehicle
in front, do not activate DISTRONIC or, if it is
already active, deactivate it. This is especially
the case:
R before corners
R on filter lanes
R when changing to a lane with faster moving
traffic
R in complex driving situations or where lanes
are diverted, e.g. at roadworks on a motor-
way
DISTRONIC PLUS otherwise maintains the
current speed set by you or accelerates up to
the set speed.
DISTRONIC PLUS cannot take account of
weather conditions. Deactivate, or do not
activate, DISTRONIC PLUS:
R if the roads are slippery, snow-covered or
icy. The wheels could lose their grip when
braking or accelerating. The vehicle could
start to skid.
R if the sensors are dirty or there is poor vis-
ibility, e.g. due to snow, rain or fog. Dis-
tance control may be impaired. 178
Driving systemsDriving and parking

Warning and display messages in the
multifunction display Example: vehicles with automatic transmission
X Activate ATTENTION ASSIST using the on-
board computer (Y page 237).
Symbol :appears in the multifunction
display.
If ATTENTION ASSIST is active, you will be
warned no sooner than 20 minutes after your
journey has begun. You then hear an inter-
mittent warning tone twice and the Atten‐
Atten‐
tion tion Assist:
Assist: Drowsiness
Drowsiness detected
detectedmes-
sage appears in the multifunction display.
X If necessary, take a break.
X Press the abutton to confirm the mes-
sage.
On long journeys, take regular breaks in good
time to allow yourself to rest properly. If you
do not take a break, you will be warned again
after 15 minutes at the earliest. This will only
happen if ATTENTION ASSIST still detects
typical indicators of fatigue or increasing lap-
ses in concentration.
ATTENTION ASSIST is reset and starts
assessing your tiredness again when you con-
tinue your journey if:
R you switch off the engine.
R you take off your seat belt and open the
driver's door, e.g. for a change of drivers or
to take a break. Speed Limit Assist
Important safety notes Speed Limit Assist shows you detected speed
limits in the multifunction display. Data from
the navigation system is also used for this purpose. If a traffic sign indicating a speed
limit or the end of a speed limit is detected,
it is shown in the multifunction display. If
Speed Limit Assist does not detect any traffic
signs, the speed limit from the digital road
map is taken and shown in the display.
Speed Limit Assist detects the traffic signs
with a camera attached behind the top of the
windscreen.
:
Speed Limit Assist camera G
WARNING
Speed Limit Assist is only an aid and may
detect speed limit signs incorrectly or not at
all.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to snow,
rain, fog or spray.
R there is glare, e.g. from the sun or from
oncoming traffic.
R the windscreen is dirty, misted up or cov-
ered, for instance by a sticker, in the vicinity
of the camera.
R the traffic signs are covered, for instance
by dirt, snow or trees.
R the traffic signs are poorly illuminated.
R there are ambiguous traffic signs, for
instance near roadworks or on multi-lane
roads.
Traffic signs always have priority over the
Speed Limit Assist display. Speed Limit Assist
cannot detect road and traffic conditions. It is
not a substitute for attentive driving. 202
Driving systemsDriving and parking