Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is run-
ning.
There may be a fault with the following, for example:
R Engine management
R Fuel injection system
R Exhaust system
R Ignition system (for vehicles with petrol engines)
R 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 155).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emergency mode is
cancelled. The vehicle does not have to be checked. æ
N
The yellow reserve fuel warning lamp lights up while the engine is running.
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. ?
N
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. The engine could be dam-
aged if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. Do not continue driving.
X Secure the vehicle against rolling away (Y page 155).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
255On-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 155).
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 283).
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 155).
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 283).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 256
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions 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 heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-start traffic. Driving systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ·
N
The red distance warning 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. ·
N
The red distance warning 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.
Further information on the distance warning function of Active Brake Assist
(Y page 67). Warning and indicator lamps in the instrument cluster
257On-board computer and displays Z
Topping up engine oil
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
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil does not spill out
over the filler neck. Allow the engine to cool
down and thoroughly clean the components
that have come into contact with engine oil
before you start the engine. H
Environmental note
When topping up the oil, take care not to spill
any. If oil enters the soil or waterways, it is
harmful to the environment.
! Use only engine oils and oil filters that are
approved for vehicles with a service system. A
list of the engine oils and oil filters that have
been tested and approved in accordance with Mercedes-Benz Specifications for Service
Products is available at any Mercedes-Benz
Service Centre.
The following cause engine failure or damage
to the exhaust system:
R Use of engine oils and oil filters that have
not been expressly approved for the service system
R Replacement of engine oil and oil filter after
the replacement interval specified by the
service system has expired
R Use of engine oil additives
! Do not add too much oil. Topping up with too
much engine oil can result in damage to the
engine or to the catalytic converter. Have
excess engine oil siphoned off. Example: engine oil filler cap
X Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 lof engine oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into
place.
X Check the oil level again with the oil dipstick
(Y page 282).
Further information on engine oil (Y page 330). 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. Engine compartment
283Maintenance and care Z
X
Park the vehicle on a level surface.
Check the coolant level only if the vehicle is
on a level surface and the engine has cooled
down.
X Turn the key to position 2in the ignition lock
(Y page 133).
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 133).
X Slowly turn cap :anti-clockwise and to
relieve excess pressure.
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 ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-Benz.
X Replace cap :and turn it clockwise as far as
it will go.
Further information on coolant (Y page 332).
Windscreen washer system 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
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. X
To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages.
If the washer fluid level drops below the recom- mended minimum of 1 litre, a message appears in the multifunction display prompting you to
top up the washer fluid (Y page 246).
Further information on windscreen washer
fluid/antifreeze (Y page 332). ASSYST PLUS
Service message
The ASSYST PLUS service interval display
informs you of the next service due date.
You can find information on the type of service
and service intervals in the Service Booklet.
You can obtain further information from a
Mercedes-Benz Service Centre.
i The ASSYST PLUS service interval display
does not show any information on the engine oil level. Observe the notes on the engine oil
level (Y page 282). 284
ASSYST PLUSMaintenance and care
i
Have the brake fluid regularly replaced at a
qualified specialist workshop and the replace-
ment confirmed in the Service Booklet. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you top up
the antifreeze. Make sure that antifreeze is
not spilled next to the filler neck. Thoroughly
clean the antifreeze from components before
starting the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found in the Mercedes-Benz Specifications for Ser-
vice Products, MB Specifications for Service
Products 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com. Or contact
a qualified specialist workshop.
! Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the replace-
ment confirmed in the Service Booklet.
Comply with the important safety precautions
for service products when handling coolant
(Y page 327).
The coolant is a mixture of water and corrosion
inhibitor/antifreeze concentrate. It is responsi-
ble for the following:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If corrosion inhibitor/antifreeze concentrate is
present in the correct concentration, the boiling
point of the coolant during operation will be
approximately 130 †. The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should:
R
be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -37 †.
R not exceed 55% (antifreeze protection down
to -45 †). Heat will otherwise not be dissipa-
ted as effectively.
Mercedes-Benz recommends a coolant or cor-
rosion inhibitor/antifreeze concentrate in
accordance with
MB Specifications for Service Products 310.1.
i When the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze and corrosion protection.
i The coolant is checked at every mainte-
nance interval at a qualified specialist work-
shop. Windscreen washer system
Important safety notes G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck.
! Only the washer fluids SummerFit and Win-
terFit can be mixed. Otherwise, the spraying
nozzles could become blocked.
Do not use distilled or de-ionised water. Other-
wise, the level sensor may give a false reading.
When handling washer fluid, observe the impor- tant safety notes on service products
(Y page 327).
At temperatures above freezing:
X Fill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB SummerFit.
Mix 1 part MB SummerFit to 100 parts water.
At temperatures below freezing:
X Fill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB WinterFit. 332
Service products and filling capacitiesTechnical data