Engine
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 engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, making sure to observe the warning notes
(Y page 305).
If you have to top up the coolant frequently: X Consult a qualified specialist workshop and have the engine cooling
system checked. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, drive on to the nearest
qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-start traffic. ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine has
overheated can cause any fluids that 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 Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 166).
X Wait until the engine has cooled down.
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 display message disappears
and the coolant temperature is below 120 †. The engine may oth- erwise be damaged.
X Pay attention to the coolant temperature gauge.
If the temperature increases again:
X Consult a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †. Display messages
249On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions Trans. oil overhea‐
Trans. oil overhea‐
ted Drive on with ted Drive on with
care care Mercedes-AMG vehicles: the transmission oil has overheated.
Manual drive program Mand the temporarily active manual drive pro-
gram are no longer available. Engine power output is reduced.
X Allow the vehicle to cool down. 4matic currently
4matic currently
unavailable unavailable 4MATIC has overheated. The vehicle is only driven by the front wheels.
X Drive on.
The airflow cools 4MATIC more quickly.
When the display message goes out, 4MATIC is available again and
the vehicle is driven by all four wheels. 4matic inoperative 4matic inoperative 4MATIC is malfunctioning. The vehicle is only driven by the front
wheels.
X Consult a qualified specialist workshop. A The tailgate is open
G WARNING
When the engine is running, exhaust gases can enter the vehicle inte- rior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. ? The bonnet is open.
A warning tone also sounds.
G WARNING
The open bonnet may then block your view when the vehicle is in
motion.
There is a risk of an accident.
X Stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions.
X Secure the vehicle against rolling away (Y page 166).
X Close the bonnet. Active bonnet mal‐ Active bonnet mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The active bonnet (pedestrian protection) is inoperative due to a mal-
function or because it has already been triggered.
X Consult a qualified specialist workshop. C At least one door is open. A warning tone also sounds.
X Close all doors. Display
messages
261On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ?
N
The red coolant warning lamp lights up while the engine is running.
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 malfunctioning.
The coolant is too hot and the engine is not being cooled sufficiently.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 166).
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, making sure to observe the
warning notes (Y page 305).
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 heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-start traffic. ?
N
The red coolant warning lamp lights up while the engine is running. 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 has overheated
can cause any fluids that 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 traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 166).
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, making sure to observe the
warning notes (Y page 305).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 274
Warning and indicator lamps on the instrument clusterOn-board computer and displays
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
! A triggered active bonnet 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 available only for certain
countries.
The active bonnet can reduce the risk of injury to
pedestrians in certain accident situations. Rais- ing the active bonnet increases the clearance tohard components, such as the engine.
If the active bonnet has been triggered, it is
raised at the rear in the area around the hinge byapproximately 60 mm.
For the drive to the workshop, reset the trig-
gered active bonnet yourself. If the active bon-
net has been triggered, pedestrian protection
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. 302
Engine compartmentMaintenance and care
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 at the
rear 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. Other-
wise, you could damage the windscreen wip-
ers 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. X
Pull support strut ?out of bracket A.
X Lift up support strut ?and insert it into yel-
low retaining clip =. Engine compartment
303Maintenance and care Z
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. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.8 litres of oil per 1,000 km.
The oil consumption may be higher than this
when the vehicle is new or if you frequently drive
at high engine speeds.
Depending on the engine, the oil dipstick may be installed at different locations.
To check the oil level:
R park the vehicle on a level surface
R the engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature
R if the engine is not at normal operating tem-
perature, e.g. if the engine was only started
briefly, wait approximately 30 minute sbefore
carrying out the measurement
Checking the oil level using the oil dip-
stick 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. Example: vehicles with a petrol engine
Example: vehicles with a diesel engine
(except the GLA 180 d model)
Example: GLA 180 d model
X All models except GLA 180 d: pull out oil
dipstick :.
X The GLA 180 d model: release the oil filler
cap and pull it out together with integrated oil dipstick :.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick :into the guide tube
to the stop, and take it out again.
If the level is between MIN mark =and MAX
mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark =or
below, top up with 1.0 lof engine oil. 304
Engine compartmentMaintenance and care
In order for the battery to achieve the maximum
possible service life, it should always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle. In such cases, have the battery disconnected at
a qualified specialist workshop. However, you
can also charge the battery with a charger rec-
ommended by Mercedes-Benz. For more infor-
mation, please contact a qualified specialist
workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for an exten- ded period. Consult a qualified specialist work-
shop if you wish to leave your vehicle parked up
for a long period of time.
When you park the vehicle, remove the key if you do not require any electrical consumers. The
vehicle will then use very little energy, thus con- serving battery power.
If the power supply has been interrupted, e.g. if
the battery was discharged, you will have to:
R set the clock using the multimedia system;
see the separate operating instructions
R reset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (Y page 113) Charging the battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only charge the battery using the jump-start
connection point.
The jump-starting connection point is in the
engine compartment (Y page 325).
X Open the bonnet.
X Connect the battery charger to the positive
terminal and earth point in the same order as
when connecting the donor battery in the
jump-starting procedure (Y page 325).
If the indicator/warning lamps do not light up in
the instrument cluster at low temperatures, it is very likely that the discharged battery has fro-
zen. In this case, you may neither jump-start the vehicle nor charge the battery. The service life of
a battery that has been thawed may be reduced. The starting characteristics may be impaired,
especially at low temperatures. Have the
thawed battery checked at a qualified specialistworkshop.
Only charge the installed battery with a battery
charger which has been tested and approved by Mercedes-Benz. A battery charger unit specially
adapted for Mercedes-Benz vehicles and tested and approved by Mercedes-Benz is available as
an accessory. This device permits charging of
the battery while it is installed. Contact a
Mercedes-Benz Service Centre for information
and availability. Read the battery charger's
operating instructions before charging the bat-
tery. 324
Battery (vehicle)Breakdown assistance
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a donor battery using jump leads. Observe the following points:
R the battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a donor battery or a jump-starting device
R vehicles with a petrol engine: jump-start the vehicle only when the engine and exhaust system
are cold
R do not start the engine if the battery is frozen. Let the battery thaw first
R jump-starting may be performed only using batteries with a nominal voltage of 12 V
R only use jump leads that are not damaged and have a sufficient cross-section and insulated
terminal clamps.
R make sure that the two vehicles do not touch
Make sure that:
R the jump leads are not damaged
R non-insulated parts of the terminal clamps do not come into contact with other metal parts while
the jump leads are connected to the battery
R the jump leads cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan
X Secure the vehicle by applying the electric parking brake.
X Manual transmission: depress the clutch pedal fully and shift to neutral.
X Automatic transmission: shift the transmission to position j.
X Turn the key to position gin the ignition lock and remove it.
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-starting
device.
X Press together cover :of positive clamp ;and slide it back.
X Connect positive terminal ;on your vehicle to positive terminal =of donor battery Busing the
jump lead. beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed. 326
Jump-startingBreakdown assistance