2014 MERCEDES-BENZ S-CLASS COUPE engine overheat

G
WARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk of an accident.
Do not switch off the ignition while driving. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only set the automatic transmission to the
respective drive positions when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. Otherwise, you could damage the
drive train.
! AMG vehicles:
at low engine oil temper-
atures (below +20 †), the maximum
engine speed is restricted in order to pro-
tect the engine. To protect the engine and
maintain smooth engine operation, avoid driving at full throttle when the engine is
cold. Key positions
Key g
To remove the key
1 Power supply for some consumers, such
as the windscreen wipers
2 Ignition (power supply for all consumers)
and drive position
3 To start the engine
If the key does not belong to the vehicle, it can still be turned in the ignition lock. However,
the ignition will not be switched on. The
engine cannot be started.
Start/Stop button General notes
All vehicles are equipped with a removable
Start/Stop button.
The Start/Stop button must be inserted in the
ignition lock and the key must be in the vehi-
cle.
When you insert the Start/Stop button into
the ignition lock, the system needs approx-
imately two seconds recognition time. You
can then use the Start/Stop button.
Pressing the Start/Stop button several times in succession corresponds to the different
key positions in the ignition lock. This is only
the case if you are not depressing the brake
pedal. Driving
159Driving and parking Z

effect, the drive wheels could lose their grip.
This increases the risk of skidding and having an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients Change into a lower gear in good time on long
and steep downhill gradients. Take particular
note of this when driving a laden vehicle.
This also applies if you have activated cruise
control, SPEEDTRONIC or DISTRONIC PLUS.
This will use the braking effect of the engine,
so less braking will be required to maintain
vehicle speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly.
Heavy and light loads G
WARNING
The braking system can overheat if you leave your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There is
a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If heavy demands are made on the brakes, do not park the vehicle immediately. Drive on for
a short while. This allows the airflow to cool
the brakes more quickly.
If the brakes have been used only moderately,
you should occasionally test their effective-
ness. To do this, brake more firmly from a
higher speed while paying attention to the
traffic conditions. This improves the grip of
the brakes. Wet road surfaces If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first time. This may also occur after a car wash orafter driving through deep water.
You will have to depress the brake pedal more
firmly. Maintain a greater distance to the vehi-
cle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads If you drive on salt-treated roads, a layer of
salt may form on the brake discs and pads.
This can increase the braking distance con-
siderably.
R In order to prevent any salt build-up, apply
the brakes occasionally while paying atten-
tion to the traffic conditions.
R Carefully depress the brake pedal at the
end of the journey and when starting the
next journey.
R Maintain a much greater distance to the
vehicle in front.
New brake discs and brake pads/
linings Brake pads/linings and discs that are either
new or have been replaced only achieve opti-
mum braking effect after several hundred kil-
ometres of driving. Compensate for the
reduced braking effect by applying greater
force to the brake pedal. Driving tips
183Driving and parking Z

R
drive slower than the stored speed without
kickdown
R set a new speed or
R call up the last speed stored again.
The SPEEDTRONIC passive
SPEEDTRONIC passive message in the
multifunction display disappears.
Deactivating variable SPEEDTRONIC
It is not possible to deactivate variable
SPEEDTRONIC by braking. There are several ways to deactivate variable
SPEEDTRONIC:
X Briefly press the cruise control lever for-
wards =.
or X Briefly press the cruise control lever in the
direction of arrow ;.
LIM indicator lamp :in the cruise control
lever goes out. Variable SPEEDTRONIC is
deactivated.
Cruise control or DISTRONIC PLUS is selec-
ted.
i The last speed stored is cleared when you
switch off the engine.
Permanent SPEEDTRONIC You can use the on-board computer to limit
the speed permanently to a value between
160 km/ h(e.g. for driving on winter tyres) and
the maximum speed (Y page 262).
Shortly before the stored speed is reached, it
appears in the multifunction display. Permanent SPEEDTRONIC remains active,
even if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed,
even if you depress the accelerator pedal
beyond the pressure point (kickdown). DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles are detected with the aid of the radar
sensor system. DISTRONIC PLUS brakes
automatically so that the set speed is not
exceeded.
Change into a lower gear in good time on long
and steep downhill gradients. Take particular
note of this when driving a laden vehicle. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and acoustically. Without your intervention,
DISTRONIC PLUS cannot prevent a collision.
An intermittent warning tone will then sound
and the distance warning lamp will light up in
the instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is
safe to do so.
DISTRONIC PLUS operates in the range
between 0 km/h and 200 km/h.
Do not use DISTRONIC PLUS while driving on roads with steep gradients. Driving systems
191Driving and parking Z

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 25). Important safety notes
G
WARNING
Operating the integrated information systems and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows messages
or warnings from certain systems in the mul- tifunction display. You should therefore make
sure your vehicle is operating safely at all times. Otherwise, a vehicle that is not oper-
ating safely may cause an accident.
If the operating safety of the vehicle is not
guaranteed, stop the vehicle at once, paying
attention to road traffic conditions. Contact a
qualified specialist workshop.
For an overview, see the instrument panel
illustration (Y page 32). Displays and operation
Rev counter
! Do not drive in the overrevving range.
Doing so will damage the engine.
The red band in the rev counter indicates the engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached. Coolant temperature gauge
G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade.
The coolant temperature is shown in the rev
counter (Y page 32).
At high outside temperatures and when driv-
ing uphill, the coolant temperature may rise.
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 124 †. 242
Displays and operationOn-board computer and displays

Engine
Display messages
Possible causes/consequences and
M
MSolutions +
Top Top
up
upcoolant
coolant See
See
Owner’s Manual
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 340).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? ? The fan motor is faulty.
X At coolant temperatures below 125 †, drive to the nearest
qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the bonnet.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 178).
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 frozen slush.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 125 †. The engine may
otherwise 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 124 †. 282
Display messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions #
See Owner's Manual See Owner's Manual The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
! Do not continue driving. The engine could otherwise overheat.
X Secure the vehicle to prevent it from rolling away (Y page 178).
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The battery is no longer being charged and the battery charge level
is too low.
A warning tone also sounds.
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 178).
X Observe the instructions in the #See Owner's Manual See Owner's Manual
display message.
X Consult a qualified specialist workshop. #
Start engine See Start engine See
Owner's Manual Owner's Manual The engine is off and the battery charge level is too low.
X Switch off electrical consumers that you do not need, such as
the rear window heating and interior lighting.
X Leave the engine running for a few minutes, or drive for a longer
distance.
The battery charges. Display
messages
283On-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 Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 178).
X Leave the vehicle and keep a safe 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 340).
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 below 125 †.
The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g. driving in
mountainous terrain and stop-start traffic. ?
N
The red coolant warning lamp comes on while the engine is running. A
warning tone also sounds.
The coolant temperature has exceeded 124 †. The airflow to the engine radi- ator 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 overhea-
ted can cause some fluids which may have leaked into the engine compart-
ment to catch fire.
In addition, steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 178).308
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 25). Engine compartment
Bonnet
Important safety notes G
WARNING
An unlocked bonnet may open while driving
and block your view. There is a risk of an acci- dent.
Never unlock the bonnet while driving. G
WARNING
When being opened and closed, the bonnet
may suddenly fall into the closed position.
There is a risk of injury to persons in the range of movement of the bonnet.
Open and close the bonnet only when nobody
is in the range of movement. G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade. G
WARNING
There are moving components in the engine
compartment. Certain components may con-
tinue to move or suddenly move again even
after the ignition has been switched off, e.g.
the radiator fan. There is a risk of injury.
If you have to carry out work in the engine
compartment:
R switch off the ignition
R never touch the dangerous areas surround-
ing moving components, e.g. the rotation
area of the fan
R remove jewellery and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts. G
WARNING
The ignition system and the fuel injection sys- tem operate with a high voltage. If you touch
the live components, you could receive an
electric shock. There is a danger of injury.
Never touch components of the ignition sys-
tem or the fuel injection system when the
ignition is switched on.
Active bonnet (pedestrian protection) Operating principle
! A triggered active bonnet must be
repaired at a qualified specialist workshop
after it has been reset. The active bonnet
function will then be available again. The
additional pedestrian protection provided
by the active bonnet will then be restored.
The active bonnet is only available in certain
countries.
The active bonnet can reduce the risk of injury to pedestrians in certain accident situations.
Raising the active bonnet increases the clear- ance to hard components, such as the engine.
If the active bonnet has been triggered, it is
raised at the rear in the area around the hinge
by approximately 85 mm.
For the drive to the workshop, reset the trig-
gered active bonnet yourself. If the active 336
Engine compartmentMaintenance and care