key battery MERCEDES-BENZ A-CLASS HATCHBACK 2015 User Guide

tion in the on-board computer, the daytime
driving lights or the side lamps and dipped- beam headlamps are switched on or off
automatically depending on the brightness of the ambient light
X To switch on the automatic headlamps:
turn the light switch to the Ãposition. G
WARNING
When the light switch is set to Ã, the
dipped-beam headlamps may not be switched on automatically if there is fog, snow or othercauses of poor visibility due to the weather
conditions such as spray. There is a risk of an
accident.
In such situations, turn the light switch to
L.
The automatic headlamp feature is only an
aid. The driver is responsible for the vehicle
lighting at all times.
The daytime driving lights improve the detect- ability of your vehicle during the day. To do
this, the daytime driving lights function must
be switched on via the on-board computer
(Y page 251).
When the side lamps and dipped-beam head- lamps are switched on, the green T(side
lamps) and L(dipped-beam headlamps)
indicator lamps in the instrument cluster light
up.
Dipped-beam headlamps
When the ignition is switched on and the light switch is in the Lposition, the side lamps
and dipped-beam headlamps are switched on even if the light sensor does not sense dark
ambient light conditions. This is advanta-
geous when there is fog or rain.
X To switch on the dipped beam head-
lamps: turn the key to position 2in the
ignition lock or start the engine.
X Turn the light switch to L.
The green Lindicator lamp in the instru-
ment cluster lights up. Rear foglamp
The rear foglamp improves the visibility of
your vehicle in heavy fog for the following
traffic. Please observe the country-specific
laws on the use of rear foglamps.
X To switch on the rear foglamp: turn the
key to position 2in the ignition lock or start
the engine.
X Turn the light switch to LorÃ.
X Press the Rbutton.
The yellow Rindicator lamp in the
instrument cluster lights up.
X To switch off the rear foglamp: press the
R button.
The yellow Rindicator lamp in the
instrument cluster goes out.
Side lamps
! If the battery has been excessively dis-
charged, the side lamps or parking lamps
are automatically switched off to enable
the next engine start. Always park your
vehicle safely and sufficiently lit according
to legal standards. Avoid the continuous
use of the Tside lamps for several
hours. If possible, switch on the Xright
or the Wleft parking lamp.
X To switch on: turn the light switch to T.
The green Tindicator lamp in the instru-
ment cluster lights up.
Parking lamps
Switching on the parking lamps ensures that
the corresponding side of the vehicle is illu-
minated.
X To switch on the parking lamps: the key
should not be in the ignition lock or it
should be in position 0.
X Turn the light switch to W(left-hand side
of the vehicle) or X(right-hand side of
the vehicle). Exterior lighting
121Lights andwindscreen wipers Z

=
v Switches the rear interior lighting
on/off
? | Switches the front interior lighting/
automatic interior lighting control off
A p Switches the right-hand front read-
ing lamp on/off
B Switches the automatic interior lighting
control on
Rear compartment control panel :
p Switches the left-hand reading lamp
on/off
; p Switches the right-hand reading
lamp on/off Interior lighting control
General notes In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except when the key is in position 2in the
ignition lock.
The colour and brightness for the ambient
lighting may be set using COMAND Online or
Audio 20 (see the separate operating instruc-
tions).
Automatic interior lighting control X
To switch on: set the switch to centre
position B.
X To switch off: set the switch to the |
position. The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the key from the ignition lock
The interior lighting is activated for a short
time when the key is removed from the igni-
tion lock. This delayed switch-off can be
adjusted using COMAND Online or Audio 20
(see the separate operating instructions).
Manual interior lighting control X
To switch the front interior lighting on:
set the switch to the cposition.
X To switch off the interior lighting: set the
switch to the |position or (if the door is
closed) to the centre position.
X To switch the rear interior lighting on or
off: press the ubutton.
X To switch the reading lamp on or off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or X Lock and then unlock the vehicle using the
key. Replacing bulbs
Important safety notes
G
WARNING
Bulbs, lamps and plug connectors can
become very hot during use. When replacing a bulb, you could burn yourself on these com-
ponents. There is a risk of injury. Replacing bulbs
125Lights and windscreen wipers
Z

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 157).
X Press the ¤button.
The indicator lamp in the ¤button lights
up or goes out. Operating the climate control system
145Climate 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. 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 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 157).
X To activate: press theebutton.
The indicator lamp in the ebutton lights
up.
THERMOTRONIC automatic climate con-
trol: air-recirculation mode is activated auto-
matically:
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 or 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. 146
Operating the climate control systemClimate control

Switching on/off
X
Turn the key to position 0in the ignition
lock or remove it (Y page 157).
X To activate: press theÃŒbutton.
The indicator lamp in the ÃŒbutton lights
up.
X To deactivate: press theÃŒbutton.
The indicator lamp in the ÃŒbutton goes
out.
i Residual heat is deactivated automati-
cally:
R after approximately 30 minutes
R when the ignition is switched on
R if the battery voltage drops
R when the auxiliary heating is switched on Auxiliary heating
Important safety notes G
DANGER
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. G
WARNING
When the auxiliary heating is switched on,
parts of the vehicle can become very hot. Flammable materials such as leaves, grass or
twigs may ignite if they come into contact
with:
R hot parts of the exhaust system
R the exhaust gas itself
There is a risk of fire.
When the auxiliary heating is switched on,
make sure that:
R no flammable materials come into contact
with hot vehicle components
R the exhaust gas can escape from the
exhaust pipe unhindered
R the exhaust gas does not come into contact
with flammable materials.
The auxiliary heating and the exhaust gas out-
let are situated in front of the right-hand front
wheel.
! 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.
Switch the auxiliary heating on regularly once
a month for about ten minutes.
The auxiliary heating timer function calcu-
lates the switch-on time according to the out-
side temperature so that the vehicle is pre-
heated by the departure time. When the
departure time is reached, the auxiliary heat- ing continues to heat for a further five
minutes and then switches off.
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 Õfull 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. 148
Operating the climate control systemClimate control

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 157).
The auxiliary heating switches off automati-
cally after 50 minutes.
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 (Y page 157).
X Set the desired temperature.
Auxiliary heating or ventilation can also be
switched on if the manually set climate con-
trol is activated. Optimum comfort is attained by setting the system 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 252).
Switching the auxiliary heating/venti-
lation on or off using the button on the
centre console General notes The colours of the indicator lamps on but-
ton
:signify the following:
R Blue: auxiliary ventilation activated
R Red: auxiliary heating activated
R Yellow: departure time preselected
(Y page 252)
Switching on the auxiliary heating/venti-
lation
X Press button :.
The red or blue indicator lamp in button :
lights up.
Switching off the auxiliary heating/venti-
lation
X Press button :.
The red or blue indicator lamp in button :
goes out.
Switching the auxiliary heating/venti-
lation on or off using the remote control General notes
Your vehicle comes with one remote control.
You may use two additional remote controls
for your vehicle. For more information, please
contact a qualified specialist workshop.
Store the remote control for the auxiliary
heating so that the auxiliary heating cannot
be switched on unintentionally. In particular,
ensure that the remote control for the auxili-
ary heating is kept out of the reach of chil-
dren.
The remote control has a range of approx-
imately 300 metres. This range is reduced by:
R sources of radio interference
R solid objects between the remote control
and the vehicle
R the remote control being in an unfavoura-
ble position in relation to the vehicle
R transmitting from an enclosed space
If the remote control battery is low, the bat-
tery symbol on the left of the display is shown as empty. Replace the remote control battery Operating the climate control system
149Climate control Z

ECO start/stop function
Introduction The ECO start/stop function switches the
engine off automatically if the vehicle is stop-
ped under certain conditions.
When pulling away again, the engine starts
automatically. The ECO start/stop function
thereby helps you to reduce the fuel con-
sumption and emissions of your vehicle.
Important safety notes G
WARNING
If the engine is switched off automatically and you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving. There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes :
ECO start/stop display
The ECO start/stop function is activated
whenever you start the engine using the key
or the Start/Stop button.
If the è ECO symbol is shown in green in
the multifunction display, the ECO start/stop
function switches the engine off automati-
cally once the vehicle stops moving.
If the ECO start/stop function has been man- ually deactivated (Y page 163) or a malfunc-
tion has caused the system to be deactivated, the è ECO symbol is not displayed.
Mercedes-AMG vehicles: the ECO start/
stop function is only available in drive pro-
gram C. Automatic engine switch-off General notes
The ECO start/stop function is operational
and the
èECO symbol is displayed in
green in the multifunction display, if:
R the indicator lamp in the ECO button is lit
green
R the outside temperature is within the range
that is suitable for the system
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 the conditions for automatic engine switch- off are not all fulfilled, the èECO symbol is
shown in yellow.
All of the vehicle's systems remain active
when the engine is switched off automati-
cally.
The engine can be switched off automatically
a maximum of four times (initial stop, then
three subsequent stops) in succession. The
è ECO symbol is shown in yellow in the
multifunction display after the engine has
been started automatically for the fourth
time. When the èECO symbol is shown in
green in the multifunction display, automatic
engine switch-off is again possible.
Vehicles with manual transmission 162
DrivingDriving and parking

Problems with the engine
Problem
Possible causes/consequences and
M
MSolutions The engine does not
start. The HOLD function or DISTRONIC PLUS is activated.
X Deactivate the HOLD function (Y page 204) or DISTRONIC
PLUS (Y page 196).
X Try to start the engine again. The engine does not
start. The starter motor
can be heard. R
There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.
Before attempting to start the engine again:
X Turn the key back to position 0in the ignition lock.
or
X Press the Start/Stop button repeatedly until all indicator lamps
in the instrument cluster go out.
X Try to start the engine again (Y page 159). Avoid excessively
long and frequent attempts to start the engine, as this will drain the battery.
If the engine does not start after several attempts: X Consult a qualified specialist workshop. The engine does not
start. The starter motor
can be heard. The
reserve fuel warning
lamp is lit and the fuel
gauge display shows 0. The fuel tank is empty.
X Refuel the vehicle. The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged.
X Jump-start the vehicle (Y page 348).
If the engine does not start despite attempts to jump-start it:
X Consult a qualified specialist workshop. The starter motor was exposed to a thermal load that was too high.
X Allow the starter motor to cool down for approximately two
minutes.
X Try to start the engine again.
If the engine still does not start:
X Consult a qualified specialist workshop. Driving
165Driving and parking Z

Problems with the fuel and fuel tank
Problem
Possible causes/consequences and
M
MSolutions Fuel is leaking from the
vehicle. The fuel line or the fuel tank is faulty.
G WARNING
There is a risk of fire or explosion. X Turn the key to position 0immediately and remove it
(Y page 157).
X Do not restart the engine under any circumstances.
X Consult a qualified specialist workshop. The engine does not
start. The fuel tank of a vehicle with a diesel engine has been run com-
pletely dry.
X Refuel the vehicle with at least 5 litres of diesel.
X Turn the ignition on for approximately ten seconds
(Y page 157).
X Start the engine continuously for a maximum of ten seconds
until it runs smoothly.
If the engine does not start:
X Turn the ignition on again a maximum of ten seconds
(Y page 157).
X Start the engine again continuously for a maximum of ten sec-
onds until it runs smoothly.
If the engine does not start after three attempts:
X Consult a qualified specialist workshop. The fuel filler flap can-
not be opened. The fuel filler flap is not unlocked.
X Unlock the vehicle (Y page 83). The key battery is discharged or nearly discharged.
X Unlock the vehicle using the emergency key element
(Y page 85). The fuel filler flap is unlocked, but the opening mechanism is jam-
med.
X Consult a qualified specialist workshop. Refuelling
183Driving and parking Z

X
Pull out release wheel =.
X Turn release wheel =anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator lamp ?
flashes. X
Press the ball coupling in the direction of
the arrow until it engages behind the
bumper.
The indicator lamp on the release knob and
the message in the multifunction display go
out. Trailer power supply
! You can connect accessories to the per-
manent power supply up to a maximum of
240 W.
You cannot charge a trailer battery using
the power supply.
When it leaves the factory, your vehicle's
trailer socket is equipped with a permanent
power supply and a power supply that is
switched on via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin
10.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest. You can find more information about fitting
the trailer electrics at a qualified specialist
workshop.
X To switch the connected power supply
on or off: turn the key to position 2or 0
respectively (Y page 157). Failure check for LEDs
If LED lamps are fitted in the trailer, a mal-
function message may appear in the multi-
function display even if there is no fault. The
reason for the error message may be that the
current has fallen below the minimum of
50 mA.
To ensure reliable operation of the failure
indicator, each LED chain in the trailer lighting
must be guaranteed a minimum current of
50 mA. Trailer with 7-pin connector
General notes Trailer with 7-pin connector:
you can con-
nect to the 13-pin socket on the ball coupling
using an adapter or, if necessary, an adapter
cable. Both can be obtained at a qualified
specialist workshop.
Fitting the adapter !
Make sure that there is sufficient cable
play so that the cable cannot become
detached when cornering.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable. 234
Towing a trailerDriving and parking