2015 MERCEDES-BENZ S-Class coolant level

Display messages
Possible causes/consequences and
M
MSolutions ?
Coolant Too Hot Coolant Too Hot
Stop Vehicle Turn Stop Vehicle Turn
Engine Off Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
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 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 220).
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 snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 257 ‡ (125 †). Other-
wise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 255 ‡ (124 †). #
See See
Operator's
Operator's Man‐
Man‐
ual
ual The battery is not being charged.
A warning tone also sounds.
Possible causes are:
R a defective alternator
R defective power electronics (PLUG-IN HYBRID vehicles)
R a torn poly-V-belt
R a malfunction in the electronics
! Do not continue driving. The engine could otherwise overheat.
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 220).
X Consult a qualified specialist workshop. Display
messages
337On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ?
N
The red coolant warning lamp comes on 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 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 220).
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 408).
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 257 ‡
(125 †). 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 mountainous
terrain, and stop-and-go traffic. ?
N
The red coolant warning lamp comes on while the engine is running. A
warning tone also sounds.
The coolant temperature has exceeded 255 ‡ (124 †). 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.
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 220).Warning and indicator lamps in the instrument cluster
365On-board computer and displays Z

Warning/
indicator
lamp
N
N Signal type
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 add coolant, observing the warning notes
(Y page 408).
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 257 ‡(125 †), you can continue driving to
the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in mountainous
terrain, and stop-and-go traffic. Hybrid system
Warning/
indicator
lamp
N
N Signal type
Possible causes/consequences and M MSolutions é
N
The yellow RBS (recuperative brake system) warning lamp is on. In addition,
there may be a warning tone.
G Risk of accident
RBS is malfunctioning. Pedal travel may be longer than usual and braking
performance may be affected. The automatic engine switch-off function may also be deactivated.
X Observe the messages in the multifunction display (Y page 316).
X Drive on carefully.
X Visit a qualified specialist workshop. 366
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Where possible, let the engine cool down and
touch only the components described 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 is not spilled next to
the filler neck. Let the engine cool down and
thoroughly clean the engine oil off the com-
ponents before starting the engine. H
Environmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a ser-
vice system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
center.
Damage to the engine or exhaust system is caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R replacing engine oil and oil filters after
the interval for replacement specified by
the service system has been exceeded
R using engine oil additives.
! Do not add too much oil. adding too much
engine oil can result in damage to the
engine or to the catalytic converter. Have
excess engine oil siphoned off. Example
X Turn cap :counter-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 :on 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 405).
Further information on engine oil
(Y page 491). 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 408
Engine compartmentMaintenance and care

opening the cap, you could be scalded by hot
coolant 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 189).
or
X Press Start/Stop button twice
(Y page 189).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
X Turn the SmartKey to position
0(Y page 189) in the ignition lock.
or
X Remove Start/Stop button from ignition
lock (Y page 189).
X Slowly turn cap :half a turn counter-
clockwise to allow excess pressure to
escape.
X Turn cap :further counter-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 ;.If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar =in the filler
neck when warm, there is enough coolant
in expansion tank ;.
X If necessary, add coolant that has been tes-
ted and approved by Mercedes-Benz.
X Replace cap :and turn it clockwise as far
as it will go.
PLUG-IN HYBRID vehicles: the second cool-
ant expansion tank must not be filled.
For further information on coolant, see
(Y page 493).
Adding washer fluid to the windshield
washer system 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
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck. Engine compartment
409Maintenance and care Z

Vehicle identification plate with vehi-
cle identification number (VIN) X
Open the front right-hand door.
X Fold cover :down and remove it.
You will see the VIN.
The VIN can also be found in the following
locations:
R on the lower edge of the windshield
(Y page 489)
R on the vehicle identification plate
(Y page 488) Engine number
:
Engine number (stamped into the crank-
case)
; VIN (on the lower edge of the windshield)
= Emission control information plate,
including the certification of both federal
and Californian emissions standards Service products and filling capaci-
ties
Important safety notes
G
WARNING
Service products may be poisonous and haz-
ardous to health. There is a risk of injury.
Comply with instructions on the use, storage
and disposal of service products on the labels of the respective original containers. Always
store service products sealed in their original containers. Always keep service products out
of the reach of children. H
Environmental note
Dispose of service products in an environ-
mentally responsible manner.
Service products include the following:
R Fuels
R Lubricants (e.g. engine oil, transmission oil)
R Coolant
R Brake fluid
R Windshield washer fluid
R Climate control system refrigerant
Components and service products must be
matched. Only use products recommended
by Mercedes-Benz. Damage which is caused
by the use of products which have not been
recommended is not covered by the
Mercedes-Benz warranty or goodwill ges-
tures. They are listed in this Mercedes-Benz
Operator's Manual in the appropriate section.
Information on tested and approved products can be obtained at an authorized Mercedes-
Benz Center or on the Internet at
http://bevo.mercedes-benz.com.
You can recognize service products approved
by Mercedes-Benz by the following inscrip-
tion on the containers:
R MB-Freigabe (e.g. MB-Freigabe 229.51)
R MB Approval (e.g. MB Approval 229.51)
Other designations or recommendations indi- cate a level of quality or a specification in Service products and filling capacities
489Technical data Z