warning light MERCEDES-BENZ A-CLASS HATCHBACK 2015 Service Manual

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). Exterior lighting
General notes
For reasons of safety, Mercedes-Benz recom- mends that you drive with the lights switched
on even during the daytime. In some coun-
tries, operation of the headlamps varies due
to legal requirements and self-imposed obli-
gations. Driving abroad
Symmetrical dipped-beam headlamps It is not necessary to switch your headlamps
to symmetrical dipped beam when driving in
countries where vehicles are driven on the
opposite side of the road to the country in
which the vehicle is registered. Legal require- ments are fulfilled without switching the
headlamps to symmetrical dipped beam. Setting the exterior lighting
Setting options Exterior lighting can be set using the:
R light switch
R combination switch (Y page 122)
R headlamp range adjustment (only vehicles
with halogen headlamps) (Y page 122)
R on-board computer (Y page 251)Light switch Operation
1
W
Left-hand parking lamps
2 X
Right-hand parking lamps
3 T
Side lamps, licence plate and instru-
ment cluster lighting
4 Ã
Automatic headlamp mode, control-
led by the light sensor
5L Dipped-beam/main-beam head-
lamps
B R
Rear foglamp
If you hear a warning tone when you leave the
vehicle, the lights may still be switched on.
X Turn the light switch to the Ãposition.
The exterior lighting (except the side lamps/
parking lamps) switches off automatically if
you: R remove the key from the ignition lock
R open the driver's door with the key in posi-
tion 0in the ignition lock.
Automatic headlamp mode
à is the preferred light switch setting. The
light setting is automatically selected accord- ing to the brightness of the ambient light
(exception: poor visibility due to weather con-
ditions such as fog, snow or spray):
R key in position 1in the ignition lock: the
side lamps are switched on or off automat- ically depending on the brightness of the
ambient light
R with the engine running: if you have
switched on the daytime driving lights func- 120
Exterior lightingLights and windscreen wipers

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

Vehicles with Adaptive Highbeam Assist:
when Adaptive Highbeam Assist is active, it
controls activation and deactivation of the
main-beam headlamps (Y page 123).
Headlamp flasher X
To switch on: turn the key in the ignition
lock to position 1or 2, or start the engine.
X Pull the combination switch in the direction
of arrow =. Hazard warning lamps
X
To 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.
X To switch off the hazard warning lamps:
press button :.
The hazard warning lamps switch on auto-
matically if:
R an airbag is deployed or
R the vehicle decelerates rapidly from a
speed of above 70 km/h and comes to a
standstill
The hazard warning lamps switch off auto-
matically if the vehicle reaches a speed of
above 10 km/h again after a full brake appli- cation.
The hazard warning lamps continue to oper-
ate even if the ignition is switched off. Adaptive Highbeam Assist
General notes You can use this function to set the head-
lamps to change between dipped beam and
main beam automatically. The system recog-
nises vehicles with their lights on, either
approaching from the opposite direction or
travelling in front of your vehicle, and conse-
quently switches the headlamps from main
beam to dipped beam.
The system automatically adapts the dipped- beam headlamp range depending on the dis-
tance to the other vehicle. Once the system
no longer detects any other vehicles, it
switches on the main-beam headlamps again.
The system's optical sensor is located behind
the windscreen near the overhead control
panel. Exterior lighting
123Lights and windscreen wipers Z

Important safety notes
G
WARNING
Adaptive Highbeam Assist does not recognise road users:
R who have no lights, e.g. pedestrians
R who have poor lighting, e.g. cyclists
R whose lighting is blocked, e.g. by a barrier
In very rare cases, Adaptive Highbeam Assist
recognises road users too late or not at all. In
this, or in similar situations, the automatic
main-beam headlamps will not be deactivated
or activated regardless. There is a risk of an
accident.
Always carefully observe the traffic conditions and switch off the main-beam headlamps in
good time.
Adaptive Highbeam Assist cannot take into
account road, weather or traffic conditions.
Adaptive Highbeam Assist is only an aid. You
are responsible for adjusting the vehicle's
lighting to the prevailing light, visibility and
traffic conditions.
In particular, the detection of obstacles can
be restricted if there is:
R poor visibility, e.g. due to fog, heavy rain or
snow
R dirt on the sensors or if the sensors are
obscured
Switching Adaptive Highbeam Assist
on/off X
To switch on: turn the light switch to Ã.
X Press the combination switch beyond the
pressure point in the direction of arrow :.
The _ indicator lamp in the multifunc-
tion display lights up when it is dark and the
light sensor switches on the dipped-beam
headlamps.
If you are driving at speeds above approx-
imately 45 km/h:
The headlamp range is set automatically
depending on the distance between the
vehicle and other road users. If you are driving at speeds above approx-
imately 55 km/h and no other road users
are detected:
The main-beam headlamps are switched on
automatically. The Kindicator lamp in
the instrument cluster also lights up.
If you are driving at speeds below approx-
imately 45 km/h or other road users are
detected or the roads are adequately lit:
The main-beam headlamps are switched off
automatically. The Kindicator lamp in
the instrument cluster goes out. The _
indicator lamp in the multifunction display
remains lit.
X To deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the multifunc-
tion display goes out. Headlamps misted up on the inside
Certain climatic and physical conditions may
cause moisture to form in the headlamp. This
moisture does not affect the functionality of
the headlamp. Interior lighting
Overview of interior lighting
Front overhead control panel :
p Switches the left-hand front reading
lamp on/off
; c Switches the front interior lighting
on 124
Interior lightingLights and windscreen wipers

=
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

!
Vehicles with a rain sensor: if the wind-
screen becomes dirty in dry weather con-
ditions, the windscreen wipers may be acti- vated inadvertently. This could damage the
windscreen wiper blades or scratch the
windscreen.
For this reason, you should always switch
off the windscreen wipers in dry weather.
Vehicles with a rain sensor: in the Äor
Ã… position, the appropriate wiping fre-
quency is automatically set according to the
intensity of the rain. In the Ã…position, the
rain sensor is more sensitive than in the Ä
position, causing the windscreen wiper to
wipe more frequently.
If the wiper blades are worn, the windscreen
will no longer be wiped properly. This could
mean you are unable to observe the traffic
conditions. Switching the rear window wiper on/
off Combination switch
:
è Switch
2 ô Wipes with washer fluid
3 ISwitches on intermittent wiping
4 0Switches off intermittent wiping
5 ô Wipes with washer fluid X
Turn the key to position 1or 2in the ignition
lock (Y page 157).
X Slide switch :on the combination switch
to the corresponding position.
When the rear window wiper is switched on,
the è symbol appears in the assistance
graphic in the instrument cluster. Further
information on the assistance graphic
(Y page 248). Replacing the wiper blades
Important safety notes G
WARNING
If the windscreen wipers begin to move while
you are changing the wiper blades, you can be trapped by the wiper arm. There is a risk of
injury.
Always switch off the windscreen wipers and
ignition before changing the wiper blades.
! To avoid damaging the windscreen wiper
blades, make sure that you touch only the
wiper arm of the windscreen wiper.
! Never open the bonnet/tailgate if a wiper
arm is folded away from the windscreen/
rear window.
Never fold a windscreen wiper arm without a wiper blade back onto the windscreen/
rear window.
Hold the windscreen wiper arm firmly when
you change the wiper blade. If you release
the wiper arm without a wiper blade and it
falls onto the windscreen/rear window, the windscreen/rear window may be damaged
by the force of the impact.
Mercedes-Benz recommends that you have
the wiper blades changed at a qualified
specialist workshop. 130
Windscreen wipersLights and windscreen wipers

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

Automatic transmission
X
Shift the transmission to position P
(Y page 170).
The transmission position indicator in the
multifunction display shows P
(Y page 170).
i You can start the engine in transmission
position Pand N.
Starting procedure with the key To start the engine using the key instead of
the Start/Stop button, pull the Start/Stop
button out of the ignition lock.
X To start a diesel engine : turn the key to
position 2in the ignition lock (Y page 157).
The % preglow indicator lamp in the
instrument cluster lights up.
X Turn the key to position 3in the ignition
lock (Y page 157) and release it as soon as
the engine is running.
Starting procedure using the Start/
Stop button The Start/Stop button can be used to start
the vehicle manually without inserting the key
into the ignition lock. The key must be in the
vehicle and the Start/Stop button must be
inserted in the ignition lock. This mode for
starting the engine operates independently of the ECO start/stop automatic engine start
function.
You can start the engine if a valid key is in thevehicle. Switch off the engine and always take
the key with you when leaving the vehicle,
even if you only leave it for a short time. Pay
attention to the important safety notes. X
Vehicles with automatic transmission:
depress the brake pedal and keep it
depressed.
X Vehicles with manual transmission:
depress the clutch pedal and keep it
depressed.
X Press the Start/Stop button once
(Y page 157).
Vehicles with a petrol engine: the engine
starts.
Vehicles with a diesel engine: preglow is
activated and the engine starts. Pulling away
General notes G
WARNING
Vehicles with automatic transmission:
If the engine speed is above the engine idling speed and you then engage transmission
position Dor R, the vehicle may accelerate
suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always keep the brake pedal firmly depressed
and do not depress the accelerator pedal at
the same time.
! Vehicles with manual transmission:
change gear in good time and avoid spin-
ning the wheels. You could otherwise dam-
age the vehicle.
Depress the accelerator carefully when pull-
ing away.
The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at any
time.
You can also deactivate the automatic locking feature (Y page 251).
Vehicles with automatic transmission: it
is only possible to shift the transmission from position Pto the desired position if you 160
DrivingDriving and pa
rking

Problem
Possible causes/consequences and
M
MSolutions Vehicles with a petrol
engine:
The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture display is showing
more than 120 †. The
coolant warning lamp
may also be on and a
warning tone may
sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 326). Observe the warning
notes as you do so and top up the coolant if necessary. If the coolant level is correct, the engine radiator fan may be faulty.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. DYNAMIC SELECT button (all vehicles
except Mercedes-AMG vehicles)
Use the DYNAMIC SELECT button to change
the drive program. Depending on the drive
program selected, the following vehicle char- acteristics will change:
R the drive (engine and transmission man-
agement)
R the suspension (vehicles with damping sys-
tem or AMG RIDE CONTROL)
R the steering
R the availability of the ECO start/stop func-
tion
R the climate control
If the ignition is switched off for less than four hours, the previously selected drive program
is activated when the engine is next started. If the ignition is switched off for more than four hours, drive program
Cis activated when the
engine is next started. X
Press DYNAMIC SELECT controller :as
many times as necessary until the desired
drive program is selected.
The selected drive program appears in the
multifunction display. After five seconds
the display goes out and the status icon of the selected drive program appears. 166
DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)Driving and parking