2012 MERCEDES-BENZ E-CLASS COUPE engine overheat

Display messages Possible causes/consequences and
M Solutions
# The battery is no
tbeing charged.
Aw arning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 177).
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is OK:
X Visit a qualified specialist workshop. 4
Check eng. oil
lev. when next
refuelling The engine oil level has dropped to the minimum level.
Aw
arning tone also sounds.
X Chec kthe oil level when next refuelling, at the latest
(Y page 309).
X If necessary, top up the engine oil (Y page 309).
X Have the engine checked at a qualified specialist workshop if
the engine oil needs topping up more often than usual. 8
Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. C There is only a very small amount of fuel in the fuel tank.
The auxiliary heating cannot be operated.
X
Refuel at the nearest filling station without fail. Display messages
261On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
?
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 mal-
functioning.
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 Secure the vehicle against rolling away (Y page 177).
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 310).
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
under 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. ?
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.
Steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
This poses 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 Secure the vehicle against rolling away (Y page 177).282
Warning and indicator lamps in the instrument clusterOn-board computer and displays

If antifreeze comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any antifreeze on hot
engine parts.
! 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 Service Products, MB Specifications for
Service Products 310.1, e.g. on the Inter-
net 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.
! The engine cooling system is filled with
coolant, which must be renewed after
15 years or after 250,000 kilometres at the
latest.
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operation will be around
130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the engine cooling system should:
R be at least 50 %. This will protect the engine
cooling system against freezing down to
around -37 †.
R not exceed 55 % (antifreeze protection
down to -45 †). Hea twill otherwise not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor- rosio
ninhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibito rcon-
centrate in accordance with MB Specifica-
tions for Service Products 310.1.
The coolant is checked at every maintenance
interval at a qualified specialist workshop.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion. Windscreen and headlam
pcleaning
system
Important safety notes G
WARNING
Windscreen washer fluid/antifreeze is highly
flammable. Avoid spilling windscreen washer
fluid/antifreeze on hot engine components as
it can ignite and burn. Severe burns could be
the result.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or
MB WinterFit. Unsuitable washer fluid
could damage the plastic lense softhe
headlamps.
! Do not use distilled or de-ionised water in
the washer fluid reservoir. Otherwise, the
level sensor may be damaged.
! Only the washer fluids SummerFit and
WinterFit can be mixed. Otherwise, the
spraying nozzles could become blocked.
At temperatures above freezing:
X Fill the washer fluid reservoir with a mixture
of water and washer fluid, e.g. MB Sum-
merFit.
Mix 1 part MB SummerFit to 100 parts water. Service products and capacities
377Technical data Z