2015 MERCEDES-BENZ E-Class SEDAN coolant temperature

Problem
Possible causes/consequences and
0050
0050Solutions 00AC
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 Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 179).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 333).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the coolant temperature is
below 248 ‡(120 †). Otherwise, the engine could be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-and-go traffic. 00AC
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds. The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow 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.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 179).288
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
0050
0050Solutions X
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 333).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-and-go traffic. Driving systems
Problem
Possible causes/consequences and
0050 0050Solutions 00BA
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.
Observe the additional information on PRE‑SAFE ®
Brake
(Y page 78).
Observe the additional information on the distance warning func-
tion of COLLISION PREVENTION ASSIST PLUS (Y page 72).Warning and indicator lamps in the instrument cluster
289On-board computer and displays Z

engine or to the catalytic converter. Have
excess engine oil siphoned off. Example
X Turn cap 0043counter-clockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, add 1.1 US qt (1.0 l)of
engine oil.
X Replace cap 0043on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil dip-
stick (Y page 332).
Further information on engine oil
(Y page 415). Additional service products
Checking coolant level G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following. G
WARNING
The engine cooling system is pressurized, par- ticularly when the engine is warm. When
opening the cap, you could be scalded by hotcoolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape. X
Park the vehicle on a level surface.
Only check the coolant level when the vehi-
cle is on a level surface and the engine has
cooled down.
X Turn the SmartKey to position 2in the igni-
tion lock (Y page 157).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 158).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
X Turn the SmartKey to position 0in the igni-
tion lock (Y page 157).
X Slowly turn cap 0043half a turn counter-
clockwise to allow excess pressure to
escape.
X Turn cap 0043further counter-clockwise and
remove it.
If the coolant is at the level of marker bar 0087
in the filler neck when cold, there is enough coolant in coolant expansion tank 0044.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar 0087in the filler Engine compartment
333Maintenance and care Z

Comply with the important safety notes for
service products when handling brake fluid
(Y page 411).
The brake fluid change intervals can be found in the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.co m.
i Have the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Maintenance
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 add anti-
freeze. 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 Service Products, MB BeVo 310.1, e.g.
on the Internet at
http://bevo.mercedes-benz.com. Or con-
tact 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
replacement confirmed in the Maintenance Booklet.
Comply with the important safety precautions
for service products when handling coolant
(Y page 411).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R corrosion protection
R antifreeze protection
R raising the boiling point
If the coolant has antifreeze protection down to -35 ‡(-37 †), the boiling point of the cool-
ant during operation is approximately 266 ‡
(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
approximately -35 ‡ (-37 †).
R not exceed 55% (antifreeze protection
down to -49 ‡[-45 †]). Other wise, heat
will not be dissipated as effectively.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in accord-
ance with MB Specifications for Service Prod-
ucts 310.1.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion.
i The coolant is checked with every main-
tenance interval at a qualified specialist
workshop. Service products and filling capacities
417Technical data Z