
! If the coolant temperature exceeds 248  ‡(120  †) do not continue driving. The engine will
otherwise be damaged.Display messagesPossible causes/consequences and  M Solutions?The engine fan is defective.XAt coolant temperatures under 248  ‡ (120  †), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.#The battery is not being charged.
Possible causes are:
R a defective alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
!  Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XVisit a qualified specialist workshop.4
Check Engine Oil 
At Next RefuelingThe engine oil level has dropped to a critical level.
A warning tone also sounds.XCheck the oil level ( Y page 281).XIf necessary, add engine oil ( Y page 282).XHave the engine checked for leaks if the engine oil needs to be
refilled more often than usual.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
!  The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
228Display messagesOn-board computer and displays 

ProblemPossible causes/consequences and M Solutions?
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.XObserve the additional display messages in the multifunction
display.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XAllow the engine and coolant to cool.XCheck the coolant level and add coolant  (Y  page  282). Observe
the warning notes.XIf you need to add coolant more often than usual, have the
engine coolant system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XAt coolant temperatures under 248  ‡ (120  †), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.?
The red coolant
warning lamp comes on
while the engine is
running. A warning tone
also sounds.The coolant temperature has exceeded 248 ‡ (120 †). The
airflow to the engine radiator may be blocked or the coolant level
may be too low.
The engine is not being cooled sufficiently and may be damaged.XObserve the additional display messages in the multifunction
display.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XAllow the engine and coolant to cool.XCheck the coolant level and add coolant  (Y  page  282). Observe
the warning notes.XIf you need to add coolant more often than usual, have the
engine coolant system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XAt coolant temperatures under 248  ‡ (120  †), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.250Warning and indicator lamps in the instrument clusterOn-board computer and displays 

Adding engine oilHEnvironmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful
to the environment.
GWARNING
If engine oil comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any engine oil on hot
engine parts.
!  Use only engine oils and oil filters that
have been approved for vehicles equipped
with a service system. A list of the engine
oils and oil filters tested and approved in
accordance with the Mercedes-Benz
Specifications for Service Products can be
called up by visiting  http://
www.mbusa.com  (USA only). More
information about tested and approved
engine oils and oil filters is available from
any authorized Mercedes-Benz Center.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters which
have not been specifically approved for
the service system.
R replacing the engine oil or oil filter after
the replacement interval required by the
service system has elapsed
R using engine oil additives.
Example: engine oil cap
XTurn cap  : counter-clockwise and remove
it.XAdd the amount of oil required.
Fill carefully to the maximum mark on the oil
dipstick.
i Depending on the engine, the difference
in quantity between the MIN mark and the
MAX mark on the dipstick is approximately
1.6 to 2.1 US qt (1.5 to 2 l).
!  Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic
converter. Have excess oil siphoned off.
For further information on engine oil, see
( Y  page 349).
XReplace cap  : on the filler neck and
tighten clockwise.
Ensure that the cap locks into place
securely.
Checking and adding other service
products
Checking the coolant level
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position
2  (Y  page 132) in the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 133).XCheck the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).GWARNING
In order to avoid any potentially serious burns:
R use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system, or
282Engine compartmentMaintenance and care  

if the coolant temperature display indicates
that the coolant is overheated.
R do not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158  ‡ (70  †). Allow the engine to
cool down before removing the cap. The
coolant reservoir contains hot fluid and is
under pressure.
R using a rag, slowly turn the cap
approximately  1
/ 2 turn to relieve excess
pressure. If opened immediately, scalding
hot fluid and steam will be blown out under
pressure.
R do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts.XSlowly turn cap  : half a turn counter-
clockwise and allow excess pressure to
escape.XTurn 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 is approximately 0.6 in
(1.5 cm) above marker bar  = in the filler
neck when warm, there is enough coolant
in coolant expansion tank  ;.XIf necessary, add coolant that has been
tested and approved by Mercedes-Benz.XReplace cap  : and turn it clockwise as far
as it will go.
For further information on coolant, see
( Y  page 350).
Windshield washer system and
headlamp cleaning system
The washer fluid reservoir is used for both the
windshield washer system and the headlamp
cleaning system.
i Vehicle components and their service
products must match. You should,
therefore, only use products that have been
tested and approved by Mercedes-Benz.
Information on tested and approved
products can be obtained at any authorized
Mercedes-Benz Center or on the Internet at
http://www.mbusa.com  (USA only).
GWARNING
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on hot engine parts, because it may
ignite and burn. You could be seriously
burned.
!  At temperatures below freezing: always
fill the washer fluid reservoir with a mix of
water and windshield washer concentrate
(e.g. MB WinterFit). There is otherwise a
risk of damaging the windshield washer
system/headlamp cleaning system.
!  Only use washer fluid concentrate which
is suitable for plastic lenses. Unsuitable
washer fluid concentrate could damage the
plastic lenses of the headlamps.
!  Do not add distilled or de-ionized water to
the washer fluid container. Otherwise, the
level sensor may be damaged.
i Add windshield washer concentrate, e.g.
MB SummerFit, to the washer fluid all year
round.
Engine compartment283Maintenance and careZ  

Internet at
http://bevo.mercedes-benz.com .
The coolant is checked at every maintenance
interval at an authorized Mercedes-Benz
Center.
The antifreeze/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 -35 ‡ (-37 † ).
R not exceed 55% (antifreeze protection to
-49 ‡ [-45 † ]); otherwise, heat will not
dissipate as effectively.
If the coolant level is too low, MB 326.0
antifreeze/corrosion inhibitor should be
added. Have the engine cooling system
checked for possible leaks.
Windshield/headlamp cleaning
system
GWARNING
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on hot engine parts, because it may
ignite and burn. You could be seriously
burned.
Use MB SummerFit windshield washer
concentrate at temperatures above freezing:
XMix 1 part MB SummerFit with 100 parts
water.
Use MB WinterFit windshield washer
concentrate at temperatures below freezing:
XAt temperatures down to 14  ‡(Ò 10  †):  mix
1 part MB WinterFit with 2 parts water.XAt temperatures down to  Ò 4  ‡( Ò 20  †):  mix
1 part MB WinterFit with 1 part water.XAt temperatures down to
Ò  20.2  ‡(Ò 29  †): mix 2 parts MB WinterFit
with 1 part water.!  Only SummerFit and WinterFit can be
mixed. Otherwise, the jets could become
blocked.
Vehicle data
Vehicle data, CLS 550
BlueEFFICIENCY
The data stated here refers specifically to a
vehicle with standard equipment. Consult an
authorized Mercedes-Benz Center for the
data for all vehicle variants and trim levels.
Vehicle dimensionsVehicle length194.6 in (4942 mm)Vehicle width 
including exterior 
mirrors81.7 in (2075 mm)Vehicle height55.3 in (1404 mm)Wheelbase113.2 in (2874 mm)Front track62.9 in (1598 mm)Rear track64.1 in (1629 mm)Turning circle37.1 ft (11.27 m)Vehicle weight 34Maximum roof 
loadMaximum trunk 
load
Vehicle data, CLS 550 4MATIC
BlueEFFICIENCY
The data stated here refers specifically to a
vehicle with standard equipment. Consult an
authorized Mercedes-Benz Center for the
data for all vehicle variants and trim levels.
34 Missing values not available at time of going to print.Vehicle data351Technical dataZ