2015 MERCEDES-BENZ A-CLASS HATCHBACK engine

Engine
Problem
Possible causes/consequences and
M
MSolutions ;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running. There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in emergency mode.
X Consult a qualified specialist workshop immediately. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 183).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked. æ
The yellow reserve fuel
warning lamp is on
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the start of the scale. The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Safeguard the vehicle against rolling away (Y page 184).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
301On-board computer/Displays Z

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 Safeguard the vehicle against rolling away (Y page 184).
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 326).
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 Safeguard the vehicle against rolling away (Y page 184).302
Warning and indicator lamps in the instrument clusterOn-board computer/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 326).
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 on the distance warning function of COL-
LISION PREVENTION ASSIST PLUS, see (Y page 70).Warning and indicator lamps in the instrument cluster
303On-board computer/Displays Z

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). Loading guidelines
G
WARNING
If objects, luggage or loads are not secured or not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, especially when braking or abruptly changing directions.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. If the tailgate is open when the engine is running, particu-
larly if the vehicle is moving, exhaust fumes
could enter the passenger compartment.
There is a risk of poisoning.
Turn off the engine before opening the tail-
gate. Never drive with the tailgate open. G
WARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury.
Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them. The handling characteristics of a laden vehi-
cle are dependent on the distribution of the
load within the vehicle. For this reason, you
should observe the following notes when
transporting a load:
R never exceed the maximum permissible
gross vehicle weight or the permissible axle
loads for the vehicle (including occupants).
R the luggage compartment is the preferred
place to carry objects.
R position heavy loads as far forwards as pos-
sible and as low down in the load compart-ment as possible.
R the load must not protrude above the upper
edge of the seat backrests.
R always place the load against the rear or
front seat backrests. Make sure that the
seat backrests are securely locked into
place.
R always place the load behind unoccupied
seats if possible.
R use the lashing eyelets and the luggage
nets to transport loads and luggage.
R only use lashing eyelets and fastening com-
ponents that are suitable for the weight and size of the load.
R the maximum load capacity of the stowage
well under the luggage compartment floor
is 25 kg.
R secure the load with sufficiently strong and
wear-resistant lashing material. pad sharp
edges for protection.
! Do not position the load on one part of the
folding luggage compartment floor only.
The maximum load capacity of the folding
luggage compartment floor is 100 kg.
Spread the weight evenly to avoid damag-
ing the luggage compartment floor. Place a
solid board under the load if necessary.
Please note that the load on the luggage
compartment floor will be increased when
the load is lashed down. 306
Loading guidelinesStowing and features

Rear-compartment ashtray
X
To open: pull cover =out by its top edge.
X To remove: pull insert;by recess :in
the direction of arrow ?until it audibly
releases.
X Lift insert ;up and out.
X To fit the insert: fit insert;from above
into the holder and press down until it
engages. Cigarette lighter
G
WARNING
You can burn yourself if you touch the hot
heating element or the socket of the cigarette lighter.
In addition, flammable materials can ignite if:
R the hot cigarette lighter falls
R a child holds the hot cigarette lighter to
objects, for example
There is a risk of fire and injury.
Always hold the cigarette lighter by the knob.
Always make sure that the cigarette lighter is
out of reach of children. Never leave children unattended in the vehicle.
Your attention must always be focused on the traffic conditions. Only use the cigarette
lighter when road and traffic conditions per-
mit. X
Turn the key to position 2in the ignition
lock (Y page 157).
X Vehicles with a stowage compartment
cover: press the lower section of cover :.
The stowage compartment opens.
X Press in cigarette lighter ;.
Cigarette lighter ;will pop out automati-
cally when the heating element is red-hot. 12 V sockets
General notes X
Turn the key to position 1in the ignition
lock (Y page 157).
The sockets can be used for accessories with a maximum draw of 180 W(15 A). Accesso-
ries include such items as mobile phone
chargers.
If you use the sockets for long periods when
the engine is switched off, the battery may
discharge.
An emergency cut-off ensures that the on-
board voltage does not drop too low. If the on-
board voltage is too low, the power to the
sockets is automatically cut. This ensures
that there is sufficient power to start the
engine. 316
FeaturesStowing and fea
tures

Useful information
............................322
Engine compartment ........................322
ASSYST PLUS .................................... 327
Care .................................................... 329 321Maintenance and care

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). Engine compartment
Bonnet
Important safety notes G
WARNING
An unlocked bonnet may open up when the
vehicle is in motion and block your view. There is a risk of an accident.
Never unlock the bonnet when driving. Before
every trip, ensure that the bonnet is locked. G
WARNING
When being opened and closed, the bonnet
may suddenly fall into the closed position.
There is a risk of injury to persons in the range of movement of the bonnet.
Open and close the bonnet only when nobody
is in the range of movement. G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade. G
WARNING
There are moving components in the engine
compartment. Certain components may con-
tinue to move or suddenly move again even
after the ignition has been switched off, e.g.
the radiator fan. There is a risk of injury.
If you have to carry out work in the engine
compartment:
R switch off the ignition
R never touch the dangerous areas surround-
ing moving components, e.g. the rotation
area of the fan
R remove jewellery and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts. G
WARNING
The ignition system and the fuel injection sys- tem operate with a high voltage. If you touch
the live components, you could receive an
electric shock. There is a danger of injury.
Never touch components of the ignition sys-
tem or the fuel injection system when the
ignition is switched on.
Active bonnet (pedestrian protection) Operating principle
! An active bonnet that had been triggered
must be repaired at a qualified specialist
workshop. The active bonnet function will
then be available again. The additional
pedestrian protection provided by the
active bonnet will then be restored.
The active bonnet is only available in certain
countries.
The active bonnet can reduce the risk of injury to pedestrians in certain accident situations.
Raising the active bonnet increases the clear-
ance to hard components, such as the engine.
If the active bonnet has been triggered, it is
raised at the rear in the area around the hinge
by approximately 60 mm.
For the drive to the workshop, reset the trig-
gered active bonnet yourself. If the active 322
Engine compartmentMaintenance and care

bonnet has been triggered, pedestrian pro-
tection may be limited.
Resetting 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. X
With your hand flat, push down active bon-
net :in the area around the hinges on
both sides (arrows) until you feel it engage.
If you can raise the active bonnet slightly in
the area around the hinges, it is not engaged correctly. Repeat the step.
If the bonnet can then still be raised, drive
directly to a qualified specialist workshop. Do
not drive faster than 100 km/h.
Opening the bonnet 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
When the bonnet is open, and the windscreen wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! Make sure that the windscreen wipers are
not folded away from the windscreen. Oth-
erwise, you could damage the windscreen
wipers or the bonnet. 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. Engine compartment
323Maintenance and care Z