2014 MERCEDES-BENZ B-CLASS HATCHBACK cooling

X
To activate: press theábutton.
The indicator lamp in the ábutton lights
up.
The temperature setting for the driver's
side is not adopted for the front-passenger side.
X To deactivate: press theábutton.
The indicator lamp in the ábutton goes
out.
The temperature setting for the driver's
side is adopted for the front-passenger
side. Demisting the windscreen
General notes You can use this function to defrost the wind-
screen or to demist the inside of the wind-
screen and the side windows.
i You should only select the "Windscreen
demisting" function until the windscreen is clear again.
Switching the "Windscreen demisting"
function on/off X
Turn the key to position 2in the ignition
lock (Y page 159).
X To activate: press the¬button.
The indicator lamp in the ¬button lights
up.
The climate control system switches to the
following functions:
R high airflow
R high temperature
R air distribution to the windscreen and
front side windows
R air-recirculation mode off
i The "Windscreen demisting" function
automatically sets the blower output to the optimum demisting effect. As a result, the
airflow may increase or decrease automat-
ically after the ¬button is pressed. i
You can adjust the blower output man-
ually while the "Windscreen demisting"
function is in operation:
R Air-conditioning system: turn airflow
control Aanti-clockwise or clockwise
(Y page 139).
R THERMOTRONIC automatic climate con-
trol: press the óorô button.
X To deactivate: press the¬button.
The indicator lamp in the ¬button goes
out. The previous settings are reactivated.
Air-recirculation mode remains deactiva-
ted.
or
X THERMOTRONIC automatic climate con-
trol: press the Ãbutton.
The indicator lamp in the ¬button goes
out. Airflow and air distribution are set to
automatic mode.
or
X Air-conditioning system: turn temperature
control :anti-clockwise or clockwise
(Y page 139).
THERMOTRONIC automatic climate con-
trol: turn temperature control :orE anti-
clockwise or clockwise (Y page 141). Demisting the windows
Windows misted up on the inside Air-conditioning system
X Activate the ¿"Cooling with air dehu-
midification" function.
X If the windows continue to mist up, activate
the ¬ "Windscreen demisting" function.
i You should only select this setting until
the windscreen is clear again. 146
Operating the climate control systemClimate control

THERMOTRONIC automatic climate con-
trol
X Activate the ¿"Cooling with air dehu-
midification" function.
X Activate automatic mode Ã.
X If the windows continue to mist up, activate
the ¬ "Windscreen demisting" function.
i You should only select this setting until
the windscreen is clear again.
Windows misted up on the outside X
Activate the windscreen wipers.
X Set the air distribution to PorO.
i You should only select this setting until
the windscreen is clear again. Rear window heating
General notes 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.
Switching on/off X
Turn the key to position 2in the ignition
lock (Y page 159).
X Press the ¤button.
The indicator lamp in the ¤button lights
up or goes out. Operating the climate control system
147Climate control

Problems with the rear window heating
Problem
Possible causes/consequences and
M
MSolutions The rear window heat-
ing has switched off
prematurely or cannot
be activated. The battery has not been sufficiently charged.
X Switch off any consumers that are not required, e.g. reading
lamps, interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window heat- ing can be activated again. Activating/deactivating air-recircula-
tion mode
General notes 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.
If you activate air-recirculation mode, the win-
dows can mist up more quickly, in particular
at low temperatures. Only use air-recircula-
tion mode briefly to prevent the windows
misting up.
The operation of air-recirculation mode is the same for all control panels.
Switching on/off X
Turn the key to position 2in the ignition
lock (Y page 159).
X To activate: press theebutton.
The indicator lamp in the ebutton lights
up.
Air-recirculation mode is activated automati-
cally:
R at high outside temperatures
R at high levels of pollution
When air-recirculation mode is activated
automatically, the indicator lamp in the e
button is not lit. Outside air is added after
about 30 minutes.
X To deactivate: press theebutton.
The indicator lamp in the ebutton goes
out. i
Air-recirculation mode is deactivated
automatically:
R after approximately five minutes at out-
side temperatures below approximately
7 †
R after approximately five minutes if the
"Cooling with air dehumidification" func-
tion is deactivated
R after approximately 30 minutes at out-
side temperatures above approximately
7 † if the cooling with air dehumidifica-
tion function is activated Convenience opening/closing using
the air-recirculation button
G
WARNING
When the convenience closing feature is oper- ating, parts of the body could become trapped
in the closing area of the side window and the
sliding sunroof. There is a risk of injury.
Observe the complete closing procedure
when the convenience closing feature is oper-
ating. When closing make sure that no parts of the body are in the closing area. G
WARNING
During convenience opening parts of the body could be drawn in or become trapped
between the side window and window frame.
There is a risk of injury.
When opening, make sure that nobody is
touching the side window. If someone
becomes trapped, press the Wswitch 148
Operating the climate control systemClimate control

Display messages
Possible causes/consequences and
M
MSolutions b
AUTO AUTO
lights
lights inoper‐
inoper‐
ative
ative The light sensor is faulty.
X Visit a qualified specialist workshop. b
Switch off lights Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã.Adaptive Adaptive
Main-beam
Main-beam
Assist currently
Assist currently
unavailable See unavailable See
Owner's Manual Owner's Manual Adaptive Highbeam Assist is deactivated and temporarily inoper-
ative. Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
X Clean the windscreen.
If the system detects that the camera is fully operational again, the
Adaptive Main-beam Assist available again
Adaptive Main-beam Assist available again message is
displayed.
Adaptive Highbeam Assist is operational again. Adaptive Adaptive
Main-beam
Main-beam
Assist inoperative
Assist inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Engine
Display messages
Possible causes/consequences and
M MSolutions +
Top Top
up
upcoolant
coolant See
See
Owner's Manual
Owner's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing so
(Y page 322).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. 268
Display
messagesOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may
be blocked or the electric engine radiator fan may be malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 181).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 322).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 181).294
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions X
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 322).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. Driving systems
Problem
Possible causes/consequences and
M MSolutions ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. The distance to the vehicle in front is too small for the speed
selected.
X Increase the distance. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
For further information about the distance warning function of
COLLISION PREVENTION ASSIST PLUS, see (Y page 74).Warning and indicator lamps in the instrument cluster
295On-board computer and displays Z

Checking and adding other service
products
Checking the coolant level G
WARNING
The engine cooling system is under pressure, particularly if the engine is warm. You could
be scalded by hot coolant spraying out when
opening the cap. There is a danger of injury.
Allow the engine to cool before opening the
cap. Wear gloves and protective eyewear
when opening. Slowly turn the cap half a turn
to allow pressure to escape.
! The coolant level must only be checked
and corrected when the engine has cooled
down (coolant temperature under 40 †).
Checking the coolant level when the cool-
ant temperature is over 40 † can lead to
damage to the engine or engine cooling
system. Example
X Park the vehicle on a level surface.
Only check the coolant level if the vehicle is
on a level surface and the engine has
cooled down.
X Turn the key to position 2in the ignition
lock (Y page 159).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
40 †.
X Turn the key to position 0in the ignition
lock (Y page 159). X
Slowly turn cap :half a turn anti-clock-
wise to allow excess pressure to escape.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough coolant in coolant expansion tank ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.
X Replace cap :and turn it clockwise as far
as it will go.
Further information on coolant (Y page 392).
Windscreen washer system G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. 322
Engine compartmentMaintenance and care

used. The low-temperature properties of
engine oils can be significantly impaired dur-
ing operation due to, for example, ageing or
soot and fuel accretion. It is therefore
strongly recommended to observe regular oil changes using an approved engine oil with the
appropriate SAE classification. Brake fluid
G
WARNING
The brake fluid continuously absorbs mois-
ture from the air. This results in the boiling
point of the brake fluid lowering. If the boiling
point of the brake fluid is too low, vapour
pockets may form when the brakes are sub-
jected to a heavy load. This would impair brak- ing efficiency. There is a risk of an accident.
Have the brake fluid renewed at the prescri-
bed intervals.
When handling brake fluid, observe the
important safety notes on service products
(Y page 386).
The brake fluid change intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.co m.
i Have the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Service
Booklet. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury. Let the engine cool down before you top up
the antifreeze. Make sure that antifreeze is
not spilled next to the filler neck. Thoroughly
clean the antifreeze from components before starting the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications for Service Products, MB Specifications for
Service Products 310.1, e.g. on the Inter-
net at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Service
Booklet.
Comply with the important safety precautions for service products when handling coolant
(Y page 386).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It is responsible
for the following:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operation will be approx-
imately 130 †. 392
Service products and capacitiesTechnical data