2014 MERCEDES-BENZ CLS coolant temperature

Engine
ProblemPossible causes/consequences andSolutions
\n
The yellow Check
Enginewarning lamp
lightsupwhile the
engineisrunning.
Theremay beamalfunction, for example:
Rin theenginemanagement
Rin thefuel injection system
Rin theexhaust system
Rin theignition system
Rin thefuel system
The emission limit values may be exceeded and theenginemay
be runninginemergencymode.
XHavethevehicle checked as soon as possible ataqualified
specialist workshop.
iIn somestates, you must immediately visitaqualified
specialist workshopassoon as theyellow CheckEngine warning
lamp lights up.This is due to the legal requirements in effect in
these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.

The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.

The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the\n
Check Enginewarning
lamp may light up.
The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed:close the fuel filler
cap.
XIf the fuel filler cap is closed:visitaqualified specialist
workshop.

The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gauge is
at the start of the scale.
The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 167).
XConsultaqualified specialist workshop.
Indicator and warning lampsinthe instrument cluster273
On-board computer and displays
Z

ProblemPossible causes/consequences andSolutions

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.
XSecure the vehicle against rolling away (Ypage 167).
XLeave the vehicle and keepasafe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning
notes (Ypage 308).
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.
XDo not start the engine again until the coolant temperature is
under 248‡(120 †). Otherwise,the engine couldbedamaged.
XDrive to the nearest qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainousterrain, and stop-and-go traffic.

The red coolant
warning lamp comes on
while the engine is
running.Awarning 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.
GWARNING
The engine is not being cooledsufficiently and may be damaged.
Do not drive whenyour engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catchfire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There isarisk of injury.
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.
XSecure the vehicle against rolling away (Ypage 167).
274Indicator and warning lampsinthe instrument cluster
On-board computer and displays

ProblemPossible causes/consequences andSolutions
XLeave the vehicle and keepasafe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning
notes (Ypage 308).
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
mountainousterrain, and stop-and-go traffic.
Driving systems
ProblemPossible causes/consequencesandSolutions

The red distance
warning lamp lights up
while the vehicle is in
motion.
The distance to the vehicle in front is too smallfor the speed
selected.
XIncrease the distance.

The red distance
warning lamp lights up
while the vehicle is in
motion.Awarning tone
also sounds.
You are approachingavehicle orastationary obstacle in your line
of travel at too highaspeed.
XBe prepared to brake immediately.
XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on PRE-SAFE®Brake (Ypage 72).
Indicator and warning lampsinthe instrument cluster275
On-board computer and displays
Z

XPark the vehicle onalevel surface.
Only check the coolant level when the
vehicle is onalevel surface and the engine
has cooled down.
XTurn the SmartKey to position2in the
ignition lock (Ypage 147).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Ypage 147).
XCheck the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158‡(70 †).
XTurn the SmartKey to position
0(Ypage 147) in the ignition lock.
XSlowly turn caphalfaturn counter-
clockwise to allow excess pressure to
escape.
XTurn capfurther 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 fuel
filler neck when warm, there is enough
coolant in expansion tank.
XIf necessary, add coolant that has been
tested and approved by Mercedes-Benz.
XReplace capand turn it clockwise as far
as it will go.
For further information on coolant,see
(Ypage 377).
Adding washer fluid to the windshield
washer system/headlampcleaning
system
GWARNING
Windshield washer concentrate is highly
flammable. If it comes intocontactwith hot
enginecomponentsorthe exhaust systemit
could ignite. There isariskoffire and injury.
Make sure that no windshield washer
concentrate is spilled nexttothe filler neck.
XTo open:pull capupwards by the tab.
XAdd the premixed washer fluid.
XTo close:press capontothe filler neck
until it engages.
The washer fluid reservoir is used for both the
windshield washer system and the headlamp
cleaning system.
If the washer fluid level drops below the
recommended minimum of1liter,amessage
appears in the multifunction display
promptingyou to refill the washer fluid
(Ypage 262).
Further information on windshield washer
fluid/antifreeze (Ypage 378).
Maintenance
ASSYST PLUS
Service messages
The ASSYSTPLUS service interval display
informsyou of the nextservice due date.
Maintenance309
Maintenance and care
Z

Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information aboutapproved brake fluid can
be obtainedatany qualified specialist
workshop or on the Internet at
http://bevo.mercedes-benz.com.
iHave the brake fluid regularly replaced at
aqualified specialist workshop and the
replacementconfirmed in the Maintenance
Booklet.
Coolant
Important safety notes
GWARNING
If antifreezecomes into contact with hot
components in the engine compartment, it
may ignite. There isarisk of fire and injury.
Let the engine cool down before you add
antifreeze. Make sure that antifreezeisnot
spilled next to the filler neck.Thoroughly
clean the antifreeze from components before
startingthe engine.
!Only add coolant that has been premixed
with the desired antifreezeprotection. You
couldotherwise 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
Internet at
http://bevo.mercedes-benz.com.Or
contactaqualified specialist workshop.
!Always useasuitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosionand
overheating.
Comply with the important safety precautions
for service products when handling coolant
(Ypage373).
The coolant isamixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
Rcorrosionprotection
Rantifreeze protection
Rraising the boiling point
If the coolant has antifreeze protection down
to -35‡(-37†),the boiling point of the
coolant during operationisapproximately
266‡(130 †).
The antifreeze/corrosion inhibitor
concentration in the engine cooling system
should:
Rbe at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35‡(-37 †).
Rnot exceed 55% (antifreeze protection
down to -49‡[-45 †]). Otherwise, heat
will not be dissipated as effectively.
If the vehicle has lost coolant, add equal
amounts of water and antifreeze/corrosion
inhibitor.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in
accordance with MB Specifications for
Service Products 310.1.
The coolant is checked with every
maintenance interval ataqualified specialist
workshop.
iWhen the vehicle is first delivered, it is
filled withacoolant mixture that ensures
adequate antifreeze and corrosion
protection.
Filling capacities
ModelCapacity
All models (except
for AMG vehicles)
Approx. 13.0 US qt
(12.3 l)
All models (AMG
vehicles)
Approx. 11.5 US qt
(10.9 l)
iUse MB 325.0 or MB 326.0 corrosion
inhibitor/antifreeze.
Service products and filling capacities377
Technical data
Z