2015 MERCEDES-BENZ B-CLASS HATCHBACK cooling

Problems with the rear window heating
Problem
Possible causes/consequences and
M
MSolutions The rear window heating
has switched off prema-
turely or cannot be acti-
vated. 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 heating
can be activated again. Switching air-recirculation mode
on/off
General notes You can deactivate the flow of fresh air if
unpleasant odours are entering the vehicle from
outside. The air already inside the vehicle 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-recirculation
mode briefly to prevent the windows misting up.
Switching on/off X
Turn the key to position 2in the ignition lock
(Y page 126).
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 auto-
matically, the indicator lamp in the ebutton
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 auto-
matically:
R after approximately five minutes at outside
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 outside
temperatures above approximately 7 † if
the cooling with air dehumidification func-
tion is activated Convenience opening or closing using
the air-recirculation button G
WARNING
When using convenience closing, you could
become trapped within the sweep of the clos- ing window. There is a risk of injury.
Monitor the entire closing procedure when
using convenience closing. When closing,
make sure that no one has any parts of the
body within 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, immediately press
the W switch in the door to stop the move-
ment of the side windows. To continue closing
the side window, pull on the Wswitch. 120
Operating the climate control systemClimate control

X
Convenience closing feature: press and
hold the ebutton until the side windows
are closed.
The indicator lamp in the ebutton lights
up. Air-recirculation mode is activated.
If parts of the body are in the closing area during convenience closing, proceed as follows:
X Press the Wbutton for opening/closing
the side windows.
The side windows stop.
X To then open the side windows, press the
W button again.
or
X Press the ebutton for longer than two
seconds.
The side windows move in the opposite direc- tion.
X Convenience opening feature: press and
hold the ebutton until the side windows
are opened. The side windows move back to
their original positions.
The indicator lamp in the ebutton goes
out. Air-recirculation mode is deactivated.
Notes on the reversing feature for the side win-
dows (Y page 82).
If you open the side windows manually after
closing them using the convenience closing fea- ture, they will remain in this position when
opened using the convenience opening feature. Pre-entry climate control via key
Before getting in, the vehicle interior can be
briefly warmed or ventilated in advance. In addi- tion, the air from the air vent can be pre-cooled.
The high-voltage battery must be sufficiently
charged before the "Pre-entry climate control
via key" function can be activated.
Activating/deactivating the pre-entry cli-
mate control (via key)
When the vehicle is unlocked using the key or
KEYLESS-GO, the climate control functions are
activated.
The pre-cooling and pre-heating climate control functions last up to 5 minutes.
When the vehicle is pre-cooled, the following
functions are activated as necessary:
R Automatic climate control
R Cooling with air dehumidification
R Blower When the vehicle is pre-heated, the following
functions are activated as necessary:
R Automatic climate control
R Blower
R Seat heating
R Windscreen heating
R Rear window heating
Pre-entry climate control is automatically
switched off when operational readiness mode
is requested.
Activating/deactivating pre-entry climate
control (via key)
You can activate and deactivate the pre-entry
climate control (via key) function using the on-
board computer in the E-CELL
E-CELL submenu
(Y page 185).
i If the charge status of the high-voltage bat-
tery is below the specified minimum charge
status, pre-entry climate control will not be
activated even if it has been set. Pre-entry climate control at departure
time and immediate pre-entry climate control
Important safety notes G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there is a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
General notes Using the "Pre-entry climate control at depar-
ture time" function, you can cool or heat the
vehicle interior prior to the desired departure
time.
When using the "Pre-entry climate control at
departure time" function, the charge status of
the high-voltage battery must be higher than the
specified minimum charge status.
The running time of the climate control may be
reduced if:
R the vehicle is not connected to an electric
power supply
R the high-voltage battery is not fully charged Operating the climate control system
121Climate control Z

With active "Pre-entry climate control at depar-
ture time" the charge status of the high-voltage
battery can be reduced, even if the charge cable connector is connected.
In certain situations, the desired interior tem-
perature cannot be reached.
When the vehicle is cooled, the following func-
tions are activated as necessary:
R Automatic climate control
R cooling with air dehumidification
R blower
When the vehicle is heated, the following func-
tions are activated as necessary:
R Automatic climate control
R Blower
R Seat heating
R Windscreen heating
R Rear window heating
"Immediate pre-entry climate control" is auto-
matically switched off when operational readi-
ness mode is requested.
Setting the departure time You can set a departure time for the "Pre-entry
climate control at departure time". Your vehicle
will then be cooled or heated until the desired
temperature is reached in time for the set depar-
ture time. "Pre-entry climate control at depar-
ture time" will be activated a maximum of
35 minutes before departure. If the departure is delayed, the vehicle will be heated or cooled fora further five minutes.
You can set the desired departure time in the E-
E-
CELL
CELL submenu on the on-board computer
(Y page 184).
Activating immediate pre-entry climate
control You can activate "Immediate pre-entry climate
control" even if the vehicle interior is already at
the desired temperature. This means, for exam- ple, that the vehicle interior continues to be
cooled or heated if the journey is interrupted for up to 50 minutes and the interior temperature iskept constant. You can only set the desired tem-
perature using the climate control unit. If you do not pre-select a temperature, the last tempera-
ture set will be automatically adopted. To activate/deactivate "Immediate pre-
entry climate control"
X Press button :in the centre console.
The blue or red indicator lamp in the button
lights up or goes out.
The colours of the indicator lamps in the button have the following meanings:
Red Heating activated
Blue Cooling activated
Yellow Pre-entry climate control at departure is preselected Switching the residual heat on/off
General notes It is possible to make use of the residual heat of
the engine to continue heating the vehicle for a
short period after the drive system has been
switched off. The heating time depends on the
set interior temperature.
i The blower will run at a low speed regardless
of the airflow setting.
i If you activate the residual heat function at
high temperatures, only the ventilation will be
activated. The blower runs at medium speed.
i You cannot use the ventilation to cool the
vehicle interior to a temperature lower than
the outside temperature. 122
Operating the climate control systemClimate control

i
Depending on the temperature, the engine
cooling system and battery cooling system
may audibly switch on when the charging
cable is connected or during the charging
process.
Removing the charging cable !
Before driving away, you must ensure that,
for your own safety and to avoid damage, the charging cable has been removed from the
vehicle socket. Otherwise, you cannot shift
the transmission out of position P.
When the charge level display reaches 100%,
the battery is fully charged (Y page 174).
The indicator lamps in the vehicle socket and on the charging cable may stay on for up to
30 seconds after the charging cable has been
disconnected.
When the battery is charged:
X Unlock the vehicle.
The Ý right indicator lamp Bon vehicle
socket Cgoes out. The Ìleft indicator
lamp Aon vehicle socket Clights up white.
X Remove the charging cable from vehicle
socket Cwithin 30 second s. Otherwise the
vehicle will relock the vehicle socket.
X Close socket cap =.
X Close the charge socket flap.
X Remove the charging cable from the mains
socket.
X Stow the charging cable safely in the vehicle
(Y page 140).
If the charging cable cannot be removed from
the vehicle socket, unlock the charge socket
flap manually using the emergency release
(Y page 143). Charging a high-voltage battery at a
charging station/wallbox
General notes When charging your vehicle from a wallbox, use
the three-phase 32 A charging cable supplied.
The charging cable is stored in a bag in the boot.
Only use charging cables that have been tested
and approved by the manufacturer for charging
the high-voltage battery in an electric vehicle.
Observe the "Important safety notes"
(Y page 134). Charging communication at a charging
station The charging station first has to be activated
before you can charge at a charging station. You
can activate the charging station by using an
RFID card or via telephone activation. Observe
the on-site operator instructions for the charg-
ing station.
When the vehicle is connected to the charging
station, information and details on technical
parameters are exchanged. It can thus take up
to 30 seconds for the charging process to begin.
Connecting the charging cable :
To open the charge socket flap
; Tyre pressure table
= Socket cap
? Reference sticker (voltage range)
A Left indicator lamp Ì
B Right indicator lamp Ý
C Vehicle socket
D Warning sticker (charging cable)
X Shift the DIRECT SELECT lever to position P.
X Switch the ignition off. 142
High-voltage batteryDriving and parking

X
Press the charge socket flap in the direction
of arrow :.
The charge socket flap swings up.
X Remove socket cap =.
X Insert the charging cable connector into vehi-
cle socket Cto the stop.
X Wallbox without a preinstalled cable: insert
the charging cable connector into the power
socket of the wallbox to the stop.
The high-voltage battery is charging.
The Ý right indicator lamp Bon vehicle
socket Cflashes green.
The vehicle must not be moved while the charg-
ing cable is connected or during charging.
i Depending on the temperature, the engine
cooling system and battery cooling system
may audibly switch on when the charging
cable is connected or during the charging
process.
Removing the charging cable !
Before driving away, you must ensure that,
for your own safety and to avoid damage, the
charging cable has been removed from the
vehicle socket. Otherwise, you cannot shift
the transmission out of position P.
When the charge level display reaches 100%,
the battery is fully charged (Y page 174).
i The indicator lamps in the vehicle socket
and on the charging cable may remain on for
up to 30 seconds after the charging cable has
been disconnected.
When the battery is charged: X Unlock the vehicle.
The Ý right indicator lamp Bon vehicle
socket Cgoes out. The Ìleft indicator
lamp Aon vehicle socket Clights up white.
X Remove the charging cable from vehicle
socket Cwithin 30 seconds. Otherwise the
vehicle will relock the vehicle socket.
X Close socket cap =.
X Close the charge socket flap.
X Wallbox without a preinstalled cable: where
necessary, remove the charging cable from
the wallbox and stow it safely in the vehicle.
If the charging cable cannot be removed from
the vehicle socket, unlock the charge socket
flap manually using the emergency release
(Y page 143). Charge socket flap emergency
release
The emergency release is located behind the
side trim panel in the luggage compartment.
X
Open the tailgate.
X Open cover ;on the left-hand side of the
luggage compartment (Y page 106).
X Pull emergency release :on the cable.
The charge socket flap is unlocked.
i The cable of emergency release
:does not
need to be detached.
X Open the charge socket flap.
i Lock and then unlock the vehicle several
times after opening the emergency release.
The cable is then automatically returned to its
initial position by an actuator. You can start
charging after you have unlocked the vehicle
again. Pay particular attention to the indicator lamps on the vehicle socket (Y page 144). High-voltage battery
143Driving and parking Z

Drive system
Display messages
Possible causes/consequences and
M
MSolutions +
Top up coolant See Top up coolant See
Owner's Manual Owner's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the cooling
system. The drive system will otherwise be damaged.
X If the coolant needs topping up more often than usual, have the
cooling system checked at a qualified specialist workshop. #
See Owner's Manual See Owner's Manual The 12 V battery is no longer being charged.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the drive system.
X Secure the vehicle against rolling away (Y page 145).
X Do not drive on.
X Do not tow the vehicle.
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The 12 V battery is no longer being charged and the battery charge
level is too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the drive system.
X Secure the vehicle against rolling away (Y page 145).
X Do not drive on.
X Do not tow the vehicle.
X Consult a qualified specialist workshop. High-voltage battery
Display messages
Possible causes/consequences and
M MSolutions Ý
Battery reserve Battery reserve
level level The charge level of the high-voltage battery has dropped into the
reserve range.
When the remaining range is 0 km, the message appears again. The
power available is then continuously reduced. The reduction in power
is represented in the E-CELL display (Y page 173).
X Charge the high-voltage battery. Û
Battery capacity Battery capacity
too too
low
lowStop
Stop Charge
Charge
immediately
immediately A warning tone also sounds. The E
‑CELL display (Ypage 173) and the
charge level display (Y page 174) go down to 0. The charge level of the
high-voltage battery is so low that operation is no longer possible. The drive system cannot be restarted.
If you then try to restart the drive system, the Battery capacity
Battery capacity
too low Stop Charge immediately too low Stop Charge immediately message appears.
X Park the vehicle and charge the high-voltage battery. 204
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions ì
Malfunction Visit Malfunction Visit
workshop workshop Malfunctions are present in the drive system and/or in the cooling
system.
X Consult a qualified specialist workshop immediately. Without starting Without starting
engine again, con‐ engine again, con‐
sult workshop sult workshop The vehicle's high-voltage electrical system is malfunctioning. A warn-
ing tone also sounds.
X Do not switch off the drive system.
X Consult a qualified specialist workshop immediately. ì
Stop Switch engine Stop Switch engine
off off There is a serious malfunction in the drive system. A warning tone also
sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Do not tow the vehicle.
X Consult a qualified specialist workshop immediately. Driving systems
Display messages
Possible causes/consequences and
M MSolutions À
Attention Assist: Attention Assist:
Take a break! Take a break! Based on certain criteria, ATTENTION ASSIST has detected fatigue or
a lack of concentration on the part of the driver. A warning tone also
sounds.
X If necessary, take a break.
During long journeys, take regular breaks in good time so that you get
enough rest. À
Attention Assist Attention Assist
inoperative inoperative ATTENTION ASSIST is inoperative.
X Consult a qualified specialist workshop. ë
Off Off The HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.
X Reactivate the HOLD function later (Y page 154). The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 154). Display
messages
205On-board computer and displays Z

X
Make sure that the windscreen wipers are
switched off.
X Pull release lever :on the bonnet.
The bonnet is released. X
Reach into the gap between the bonnet and
the radiator trim and press bonnet catch
lever ;to the left.
X Raise the bonnet. X
Pull support strut ?out of bracket A.
X Lift up support strut ?and insert it into yel-
low retaining clip =.
Closing the bonnet X
Raise the bonnet slightly and, at the same
time, remove support strut ?from yellow
retaining clip =.
X Swing support strut ?down and press it into
bracket Auntil it engages.
X Lower the bonnet and let it fall from a height
of approximately 20 cm.
X Check that the bonnet has engaged properly.
If the bonnet can be raised slightly, it is not
properly engaged. Do not press the bonnet
closed. Open the bonnet again and close it
with a little more force. Checking and adding other service
products
Checking the coolant level G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure.
! 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 coolant tempera-
ture is over 40 † can lead to damage to the
engine or engine cooling system. X
Park the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the drive system has
cooled down.
X Turn the key to position 2in the ignition lock
(Y page 126).
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 126).
X Slowly turn cap :anti-clockwise 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 ;.240
Engine compartmentMaintenance and care