2012 MERCEDES-BENZ CLS COUPE cooling

Display messages Possible causes/consequences and
M Solutions
Adaptive Main-beam
Assist inoperative Adaptive Highbeam Assis
tisfaulty.
X Visit aqualified specialist workshop. Adaptive Main-beam
Assist currently
unavailable See
Owner's Manual Adaptive Highbeam Assist is deactivated and temporarily inoper-
ative. Possible causes:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
X Cleant he windscreen.
If the system detectst hat the camera is fully operational again,
the Adaptive Main-beam Assist available again message
is displayed.
Adaptive Highbeam Assist is operational again. Engine
Display messages Possible causes/consequencesa
ndM Solutions
+
Top
up coolant See
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, observing the warning notes before doing
so (Y page 299).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at aqualified specialist work-
shop. ? The fan motor is faulty.
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. 240
Display messagesOn-board computer and displays

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 159).
X Leave the vehicle and keep asafe 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 299).
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.
Awarning 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 compartmen ttocatch fire.
Steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
This poses arisk 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 159).268
Warning and indicator lampsint
he instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
X
Leave the vehicle and keep asafe 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 299).
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 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
Problem Possible causes/consequences and
M Solutions
·
The red distance warn-
ing 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. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion.
Aw
arning tone also
sounds. You are approaching
avehicle or astationar yobstacle in your line
of travel at to ohigh aspeed.
X Be prepared to brak eimmediately.
X Pay careful attentio ntothetraffic situation. You may have to
brak eort akee vasive action.
Further informatio nonDISTRONICPLUS(Ypage 170).
Further informatio nonPRE-SAFE ®
Brake (Y page 68). Warning and indicator lamps in th
einstrumen tcluster
269On-boar dcomputer and displays Z

X
Replac ecap : on th efiller neck and turn
clockwise.
Mak esuret hatthe cap locks securel yinto
place.
X Chec kthe oil level again with the oil dip-
stick (Y page 298).
For further information on engine oil, see
(Y page 363). Other service products
Checking the coolant level G
WARNING
The cooling system is pressurised. Therefore,
only unscrew the cap once the engine has
cooled down. The coolant temperature gauge
must display less than 70 †.Otherwise, you
could be scalded if hot coolant escapes. X
Park the vehicl eonalevel surface.
Onl ycheck the coolant level if the vehicle
is on alevel surface and the engine has
coole ddown.
X Turn the key to position 2in the ignition
lock (Y page 141).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 141).
X Check the coolant temperatur edisplay in
the instrument cluster.
Th ec oolant temperatur emustbeb elow
70 †.
X Turn the key to position 0(Y page 141) in
the ignition lock. X
Slowl yturnc ap : half aturna nti-clock-
wise to allow exces spressure to escape.
X Turn cap :further anti-clockwis eand
remove it.
If th ecoolan tisatt heleve lofm arkerbar
= in th efille rneck when cold, ther eis
enough coolant in coolant expansion
tank ;.
If the coolant level is approximately
1.5 cm above marker bar =in the filler
neckw hen warm, 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.
For further information on coolant, see
(Y page 365).
Topping up the windscreen washer sys-
tem/headlam pcleaning system G
WARNING
Windscreen washer fluid/antifreez eishighly
flammable. Avoid spilling windscreen washer
fluid/antifreez eonhot engin ecomponent sas
it can ignit eand burn. Severe burns could be
the result. X
To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :ontothe filler neck
until it engages. Engine compartment
299Maintenance and care Z

shows you which SAE classifications are to be
used. The low-temperature properties of
engine oils can be significantly impaired dur-
ing operation due to, for example, ageing or
soot and fuel accretion. It is therefore
strongly recommended to observe regularo il
changes using an approved engine oil with the
appropriate SA Eclassification. Brake fluid
G
WARNING
Over aperiod of time, the brak efluid absorbs
moisture fro mthe air; This lowers its boiling
point.
If the boiling point of the brake fluid is too low,
vapour pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This impairs braking effi-
ciency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change inter-
vals can be found in the Service 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.com.
i Have the brake fluid renewed regularly at
aq ualified specialist workshop. Coolant
Important safety notes G
WARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when han-
dling antifreeze.
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 otherw ised amage 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 aqualified specialist workshop.
! Always use asuitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosio nand
overheating.
! The engine cooling system is filled with
coolant, which must be renewe dafter
15 years or after 250,000 kilometres at the
latest.
The coolant is amixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosio nprotection
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 willbea pprox-
imatel y130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the engine cooling system should:
R be at least 50%. Thi swillp rotect the engine
cooling system against freezing dow nto
approximately -3 7†.
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-
mend sana ntifreeze/corrosion inhibito rcon-
centrate in accordanc ewith MB Specifica-
tions for Servic eProducts 310.1. Service products and capacities
365Technical data Z