engine overheat MERCEDES-BENZ CLS 2011 Owners Manual

G
Warning!
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps
R malfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible. :
Reset button
For information on changing the instrument
cluster settings, e.g. the language, see
(Y page 119). Activating the instrument cluster
The instrument cluster is activated when you
R open a front door
R switch on the ignition
R press reset button :
R switch on the exterior lamps Adjusting the instrument cluster
illumination
X To brighten illumination: Turn reset
button : clockwise until the desired level
of illumination is reached.
X To dim illumination: Turn reset
button : counterclockwise until the
desired level of illumination is reached.
i The instrument cluster illumination is
dimmed or brightened automatically to suit
ambient light conditions.
The instrument cluster illumination will also
be adjusted automatically when you switch
on the vehicle’s exterior lamps. Coolant temperature indicator
G
Warning!
Driving when your engine is overheated can
cause some fluids which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until
the engine has cooled down.
During severe operating conditions, e.g. stop-
and-go traffic, the coolant temperature may
rise close to 248‡ (120†).
! Excessive coolant temperature triggers a
warning in the multifunction display and the
red coolant temperature warning
lamp ? in the instrument cluster comes
on.
The engine should not be operated with a
coolant temperature above 248‡ (120†).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty. Instrument cluster
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Mercedes-Benz Center to have the fuel
system drained completely.
! To prevent damage to the catalytic
converters, only use premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel may
reach the catalytic converter, causing it to
overheat and potentially start a fire.
i Only use premium unleaded gasoline with
a minimum Posted Octane Rating of 91
(average of 96 RON/86 MON).
Information on gasoline quality can
normally be found on the fuel pump. Please
contact gas station personnel in case
labels on the pump cannot be found.
For more information on gasoline, see
“Premium unleaded gasoline”
(Y page 299), see “Fuel requirements”
(Y page 299), or contact an authorized
Mercedes-Benz Center, or visit
www.mbusa.com (USA only).
Locking/unlocking the vehicle with the
SmartKey or KEYLESS-GO automatically
locks/unlocks the fuel filler flap.
i In case the central locking system does
not release the fuel filler flap, see “Fuel filler
flap” (Y page 263).
The fuel filler flap is located on the right-hand
side of the vehicle towards the rear. X
Turn off the engine. i
Leaving the engine running and the fuel
filler cap open can cause the yellow fuel
tank reserve warning lamp to flash and the
malfunction indicator lamp = (USA
only) or ; (Canada only) to illuminate.
For more information, see also “Practical
hints” (Y page 257).
X Remove the SmartKey from the starter
switch.
KEYLESS-GO: Open the driver’s door. This
puts the starter switch in position 0, same
as with the SmartKey removed from the
starter switch. The driver’s door then can
be closed again.
X Opening: Press fuel filler flap : at the
point indicated by the arrow.
X Turn fuel filler cap ; counterclockwise.
X Take off fuel filler cap ;.
X Place fuel filler cap ; in direction of arrow
into holder =.
X Fully insert filler nozzle unit and refuel.
X Only fill your tank until the filler nozzle unit
cuts out – do not top off or overfill .
X Closing: Turn fuel filler cap ; clockwise
until it audibly engages.
i Close the fuel filler flap before locking the
vehicle. Otherwise the flap locking pin will
prevent closing the fuel filler flap.
X Close fuel filler flap :. Check regularly and before a long trip
For information on quantities and
requirements of operating agents, see “Fuels,
coolants, lubricants, etc.” (Y page 296).
Check the following:
R Engine oil level ( Y page 179)
R Tire inflation pressure ( Y page 185)
R Coolant level ( Y page 180)
R Vehicle lighting ( Y page 266) At the gas station
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R
Washer system and headlamp cleaning
system (Y page 181)
R Brake fluid ( Y page 182) Engine compartment
Hood
G
Warning!
Do not pull the release lever while the vehicle
is in motion. Otherwise the hood could be
forced open by passing air flow.
This could cause the hood to come loose and
injure you and/or others.
Opening G
Warning!
If you see flames or smoke coming from the
engine compartment, or if the coolant
temperature indicator indicates that the
engine is overheated, do not open the hood.
Move away from vehicle and do not open the
hood until the engine has cooled. If necessary,
call the fire department. G
Warning!
You could be injured when the hood is open –
even when the engine is turned off.
Parts of the engine can become very hot. To
prevent burns, let the engine cool completely
before touching any components on the
vehicle. Comply with all relevant safety
precautions. G
Warning!
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades. G
Warning!
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnostic
socket) of the ignition system
R with the engine running
R while starting the engine
R when the ignition is switched on and the
engine is turned manually X
Pull hood lock release lever :.
The hood is unlocked.
! Never open the hood if the wiper arms are
folded forward away from the windshield.
Otherwise the windshield wipers or the
hood could be damaged. X
Push handle ; under the hood upwards.
X Pull up on the hood and then release it.
The hood will be held open at shoulder
height by gas-filled struts automatically. 178
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G
Warning!
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
if the coolant temperature indicator
indicates that the coolant is overheated.
R Do not remove the cap on the coolant
expansion tank if the coolant temperature
is above 158‡ (70†). Allow the engine to
cool down before removing the cap. The
coolant expansion tank contains hot fluid
and is under pressure.
R Using a rag, slowly open the cap
approximately 1
/ 2 turn counterclockwise
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. X
Using a rag, slowly open cap :
approximately 1
/ 2 turn counterclockwise
to relieve excess pressure.
X Continue turning cap : counterclockwise
and remove it. The coolant level is correct if the level
R
for cold coolant: reaches marking bar
= in coolant expansion tank ;
R for warm coolant: is approximately 0.6 in
(1.5 cm) higher
X Add coolant as required.
X Screw cap : back on and tighten it.
For more information on coolant, see the
“Technical data” section ( Y page 297) and
(Y page 300). Washer system and headlamp
cleaning system
G
Warning!
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.
! Always use washer solvent/antifreeze
where temperatures may fall below
freezing point. Failure to do so could result
in damage to the washer system/fluid
reservoir.
! Only use washer fluid which is suitable for
plastic lenses. Improper washer fluid can
damage the plastic lenses of the
headlamps.
! Do not use distilled or deionized water in
the washer fluid reservoir. Otherwise, the
washer fluid level sensor could be
damaged.
Fluid for the washer system and the headlamp
cleaning system is supplied from the washer
fluid reservoir.
During all seasons, use MB Windshield
Washer Concentrate “MB SummerFit”. Mix it
with water or premixed washer solvent/
antifreeze depending on the ambient
temperature ( Y page 302). Engine compartment
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Driving instructions
Drive sensibly – save fuel
To save fuel you should:
R Keep tires at the recommended inflation
pressures.
R Remove unnecessary loads.
R Remove roof rack when not in use.
R Allow engine to warm up under low load
use.
R Avoid frequent acceleration and
deceleration.
R Have all maintenance work performed at
the intervals specified in the Maintenance
Booklet and as required by the
Maintenance system. Contact an
authorized Mercedes-Benz Center.
Fuel
consumption is also increased by driving
in cold weather, in stop-and-go traffic, on
short trips and in mountainous areas. Drinking and driving
G
Warning!
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident

are greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs. Pedals
G
Warning!
Make sure absolutely no objects are
obstructing the pedals’ range of movement.
Keep the driver’s footwell clear of all obstacles. If there are any floormats or
carpets in the footwell, make sure that the
pedals still have sufficient clearance.
During sudden driving or braking maneuvers,
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.
Power assistance
G
Warning!
There is no power assistance for the steering
and
the brake when the engine is not running.
Steering and braking requires significantly
more effort and you could lose control of the
vehicle and cause an accident as a result.
Do not turn off the engine while the vehicle is
in motion. Brakes
Downhill grades !
When driving down long and steep
grades, relieve the load on the brakes by
shifting into a lower gear to use the
engine’s

braking power. This helps prevent
overheating of the brakes and reduces
wear.
When using the engine’s braking power, a
drive wheel may not spin for an extended
period of time, e.g. on slippery road
surfaces. This may cause serious damage
to the drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Continuous or hard braking G
Warning!
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads. 210
Driving instructions
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It can also result in the brakes overheating,
thereby significantly reducing their
effectiveness. It may not be possible to stop
the vehicle in sufficient time to avoid an
accident.
After hard braking, it is advisable to drive on
for
some time, rather than immediately park,
so that the air stream will cool down the
brakes faster.
Wet roads G
Warning!
After driving in heavy rain for some time
without
applying the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced and increased pedal pressure may be
necessary to obtain expected brake effect.
Maintain a safe distance from vehicles in
front.
To help prevent brake disk corrosion after
driving on wet or salt-covered roads, it is
advisable to brake the vehicle with
considerable force prior to parking. The heat
generated serves to dry the brakes.
Salt-covered roads G
Warning!
A layer of salt on the brake discs and the brake
linings may cause a delay in the braking
effect, resulting in a significantly increased
braking distance, which could lead to an
accident.
To avoid this danger, you should:
R occasionally brake carefully when you are
driving on salt-covered roads, so that any
layer of salt that may have built up on the
brake discs and the brake linings is removed without putting other road users
at risk
R maintain a greater distance to the vehicle
ahead and drive with particular care
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new

trip, so that salt residues are removed
from the brake disc
Brake service !
The brake fluid level in the reservoir may
be

too low if the brake warning lamp in the
instrument cluster comes on and an
acoustic warning sounds although the
parking brake is released. Observe
additional messages in the multifunction
display that may appear.
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the
reservoir.
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Only install brake pads and use brake fluid
recommended by Mercedes-Benz. G
Warning!
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle

can be degraded to an extent that safe
braking is substantially impaired. This could
result in an accident.
! Because the ESP ®
operates
automatically, the engine and ignition must
be shut off (SmartKey in starter switch
position 0 or 1 or KEYLESS-GO start/stop
button in position 0 or 1) when the parking
brake is being tested on a brake test Driving instructions
211
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Display messages
Possible causes/consequences and
X SolutionsDISTRONIC Currently
Unavailabl
e
See
Operator’s
Manual Distronic is deactivated because:
R
The Distronic cover in the radiator grille is dirty.
R The functionality is impaired by heavy precipitation or fog.
R The system is overheated.
X If necessary, clean the Distronic cover in the area of the
radiator grille
(Y page 219).
X If necessary, wait until the system has cooled down.
X Restart the vehicle.
Distronic becomes operational again without the engine being
restarted when
R dirt on the radiator grille has fallen off while driving (e.g.
slush or snow)
R the system recognizes full sensor availability (due to
lessening rain or the road surface drying)
R the message in the multifunction display disappears
R the speed last stored flashes in the display for 5 seconds
You can then operate Distronic as usual again. DISTRONIC Currently
Unavailabl
e
See
Operator’s
Manual Distronic is deactivated because the functionality is impaired
by external interferences, e.g. high-frequency sources such
as toll stations, speed measuring systems etc.
X
Leave the area of the external interference.
X Activate Distronic again (Y
page 133) when the message in
the multifunction display disappears. Distronic is deactivated because the Distronic sensor has not
sensed any other vehicles or objects, e.g. road sign or such,
for a long time.
X
Activate Distronic again (Y
page 133) when the message in
the multifunction display disappears. G
Warning!
Distronic cannot take weather conditions into
account.
Switch off Distronic or do not turn it
on if the sensor is dirty or visibility is
diminished as a result of snow, rain or fog. The
distance control may be impaired even before the system is able to detect a dirty sensor. The
message
DISTRONIC Currently
Unavailable

See Operator’s Manual will
be displayed in the multifunction display and
Distronic will be turned off. 234
Vehicle status messages in the multifunction display
Practical hints
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Engine
Display messages
Possible causes/consequences and
X Solutions=
(USA only)
;
(Canada
only) Engine
Service There may be a malfunction in
R
the fuel management system
R the ignition system
R the exhaust system
R the fuel system
X Have the engine checkedas soon as possible at an
authorized Mercedes-Benz Center. ; Display
Malfunctio
n
Service
Required Certain electronic systems are unable to relay information to
the control system. The coolant temperature display or the
tachometer may have failed.
X
Have the electronic systems checked at an authorized
Mercedes-Benz Center. + Top Up
Coolant
See
Operator’s
Man. The coolant level is too low.
X
Add coolant (Y page 180).
X If you have to add coolant frequently, have the cooling
system checked at an authorized Mercedes-Benz Center. G
Warning!
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! Do not ignore the low engine coolant level warning. Extended driving with the message
and
symbol displayed may cause serious engine damage not covered by the Mercedes-Benz
Limited Warranty.
Do not drive without sufficient amount of coolant in the cooling system. The engine will
overheat causing major engine damage. Vehicle status messages in the multifunction display
243
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Display messages
Possible causes/consequences and
X Solutions? Coolant
Stop
Vehicle,
turn
engine
off. The coolant is too hot.
X
Stop the vehicle immediately as soon as it is safe to do so.
X Turn off the engine immediately.
X Engage the parking brake.
X Only start the engine again after the message disappears.
You could otherwise damage the engine.
X Observe the coolant temperature indicator in the
instrument cluster.
X If the temperature rises again: Contact an authorized
Mercedes-Benz Center immediately.
During severe operation conditions and stop-and-go city
traffic, the coolant temperature may rise close to 248‡
(120†). G
Warning!
Driving when your engine is overheated can cause some fluids which may have leaked into the
engine compartment to catch fire. You could be seriously burned.
Steam
from an overheated engine can cause serious burns which can occur just by opening the
engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until the engine has cooled down.
! The engine should not be operated with the coolant temperature above 248‡ (120†).
Doing so may cause serious damage which is not covered by the Mercedes-Benz Limited
Warranty. 244
Vehicle status messages in the multifunction displayPractical hints
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Display messages
Possible causes/consequences and
X Solutions? Coolant
Stop
Vehicle,
turn
engine
off. The poly-V-belt could be broken.
X
Stop the vehicle immediately as soon as it is safe to do so.
X Turn off the engine immediately.
X Check the poly-V-belt.
X If it is broken: Do not continue to drive. Otherwise the
engine will overheat due to an inoperative water pump
which may result in damage to the engine. Contact an
authorized Mercedes-Benz Center.
X If it is intact: Do not continue to drive the vehicle with this
message displayed. Doing so could result in serious engine
damage that is not covered by the Mercedes-Benz Limited
Warranty.
X Observe the coolant temperature indicator in the
instrument cluster.
X Drive to the nearest authorized Mercedes-Benz Center
immediately. ? The radiator cooling fan is malfunctioning.
X
Observe the coolant temperature indicator in the
instrument cluster.
If

the coolant temperature is below 248‡ (120†), you may
continue driving to an authorized Mercedes-Benz Center.
X Avoid placing heavy loads on the engine (e.g. by driving
uphill) as well as stop-and-go traffic.
X Have the fan replaced as soon as possible. # The battery is no longer charging.
Possible causes:
R
alternator malfunctioning
R broken poly-V-belt
R a malfunction in the electronic system
X Stop immediately in a safe location or as soon as it is safe
to do so and check the poly-V-belt.
X If it is broken: Do not continue to drive. Otherwise the
engine will overheat due to an inoperative water pump
which may result in damage to the engine. Contact an
authorized Mercedes-Benz Center.
X If it is intact: Drive to the nearest authorized Mercedes-
Benz Center immediately. Adjust driving to be consistent
with reduced braking responsiveness. Vehicle status messages in the multifunction display
245
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