2014 MERCEDES-BENZ C-CLASS SALOON engine overheat

boosting effect. You will require considerably
more effort to steer and brake. There is a riskof 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.
Hybrid vehicles: observe the safety instruc-
tions for hybrid vehicles (Y page 269).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 Starting the engine
i If the key does not belong to the vehicle, it
can still be turned in the ignition lock. How-
ever, the ignition will not be switched on
The engine cannot be started.
Vehicles with AIRPANEL: you can open the
shutters in the radiator trim by turning the key to position 2in the ignition lock. After approx-
imately 120 seconds the shutters open auto-
matically. Further information on opening and cleaning the shutters (Y page 400).
Start/Stop button General notes
A check which periodically establishes a radio
connection between the vehicle and the key
determines whether a valid key is in the vehi-
cle. This occurs, for example, when starting
the engine.
To start the vehicle without actively using the key:
R the Start/Stop button must be inserted in
the ignition lock
R the key must be in the vehicle
R the vehicle must not be locked with the key
or KEYLESS-GO (Y page 91)
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.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
Do not keep the key:
R with electronic devices, e.g. a mobile
phone or another key
R with metallic objects, e.g. coins or metal
film
R inside metallic objects, e.g. a metal case
This can affect the key's functionality. Driving
181Driving and parking Z

time, the driver has adopted the most eco-
nomical driving style for the selected settings
and prevailing conditions. The ECO display
border lights up.
The ECO display does not indicate the actual fuel consumption. The additionally achieved
range displayed under Bonus fr. start Bonus fr. start
does not indicate a fixed consumption reduc-
tion.
In addition to driving style, the actual con-
sumption is affected by other factors, such
as:
R load
R tyre pressure
R cold start
R choice of route
R the use of electrical consumers
These factors are not included in the ECO dis-
play.
An economical driving style involves driving at a moderate engine speed.
To achieve a higher value in the categories
"acceleration" and "smooth driving":
R observe the gearshift recommendation
R drive the vehicle in drive program E(vehi-
cles with the AGILITY SELECT switch)
On long journeys at a constant speed, e.g. on the motorway, only the outer area for "con-
stant" will change.
The ECO display summarises the driving style
from the start of the journey to its completion. Therefore, there are more marked changes in
the outer areas at the start of a journey. Dur- ing a prolonged driving time, these changes
are smaller. For more marked changes, per-
form a manual rest (Y page 299).
Further information on the ECO display
(Y page 298). Brakes
Important safety notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
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 and
when towing a trailer.
This also applies if cruise control, DISTRONIC
PLUS or SPEEDTRONIC are activated.
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. Driving
tips
213Driving an d parking Z

Driving systems
Mercedes-Benz Intelligent Drive
Mercedes-Benz Intelligent Drive stands for
innovative driver assistance and safety sys-
tems which enhance comfort and support the
driver in critical situations. With these intelli-
gent co-ordinated systems Mercedes-Benz
has set a milestone on the path towards
autonomous driving.
Mercedes-Benz Intelligent Drive embraces all elements of active and passive safety in one
well thought-out system – for the safety of thevehicle occupants and that of other road
users.
Further information on driving safety systems
(Y page 74). Cruise control
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order to avoid exceeding the set speed. Change into
a lower gear in good time on long and steep
downhill gradients. Take particular note of
this when driving a laden vehicle and when
towing a trailer. 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.
Use cruise control only if road and traffic con- ditions are appropriate for maintaining a
steady speed for a prolonged period. You can store any road speed above 30 km/h.
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account road,
weather or traffic conditions. Cruise control is
only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed, for braking in good time, and for staying in
lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed
(e.g. in heavy traffic or on winding roads)
R on smooth or slippery roads. Braking or
accelerating can cause the drive wheels to
lose traction and the vehicle could then
skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever :
To store the current speed or a higher
speed
; LIM indicator lamp
= To store the current speed and to call up
the last stored speed
? To store the current speed or a lower
speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate cruise control
You can operate cruise control and variable
SPEEDTRONIC with the cruise control lever. 216
Driving syste
msDriving and parking

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.
Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly rec-
ognise other road users and complex traffic
conditions.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be prepared to
brake, particularly if DISTRONIC PLUS warns
you. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this deceleration is not sufficient,
DISTRONIC PLUS alerts you with a visual and
acoustic warning. There is a risk of an acci-
dent.
Apply the brakes yourself in these situations
and try to take evasive action.
! If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow-
ing or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style,
DISTRONIC PLUS can neither reduce the risk
of an accident nor override the laws of phys-
ics. DISTRONIC PLUS cannot take road and
weather conditions or traffic conditions into
account. DISTRONIC PLUS is only an aid. You
are responsible for the distance to the vehicle 222
Driving systemsDriving and parking

brake system and prevents the brakes from
overheating and wearing too quickly. If you
need additional braking, depress the brake
pedal repeatedly rather than continuously.
Driving tips If the trailer swings from side to side:
X Do not accelerate.
X Do not countersteer.
X Brake if necessary.
R Maintain a greater distance to the vehicle in
front than when driving without a trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine,
and consequently the vehicle's gradient-
climbing capability, decrease with increas-
ing altitude. Folding out the ball coupling
G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is a risk of an
accident.
Always engage the ball coupling as described. G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that the ball coupling engages when folding in.
Before you can tow a trailer with your vehicle, you must fold out the ball coupling.
X Make sure that the vehicle is stationary. X
Open the boot lid.
X Pull release knob :until the ball coupling
unlocks.
The ball coupling folds out from under the
rear bumper.
The indicator lamp on the release knob
flashes. The trailer socket folds away auto- matically. X
Press the ball coupling in the direction of
the arrow until it engages in a vertical posi-
tion.
The indicator lamp on the release knob
goes off.
The multifunction display shows the
Trailer Trailer hitch
hitchCheck
Checklock
lockmech.
mech. mes-
sage until the ball coupling is engaged.
X Remove the protective covering from the
ball coupling and store it in a safe place.
Hybrid vehicles: observe the safety instruc-
tions for hybrid vehicles (Y page 269). Towing a trailer
285Driving and parking Z

Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated (Y page 216):
The segments light up from the stored
speed to the maximum speed.
R Variable SPEEDTRONIC activated
(Y page 219):
The segments light up from the start of the
scale to the selected limit speed.
R DISTRONIC PLUS activated (Y page 222):
One or two segments in the set speed
range light up.
R DISTRONIC PLUS detects a vehicle in front:
The segments between the speed of the
vehicle in front and the stored speed light
up. 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. Outside temperature display
You should pay special attention to road con-
ditions when temperatures are around the
freezing point.
Bear in mind that the outside temperature
display indicates the temperature measured
and does not record the road temperature.
The outside temperature display is in the mul- tifunction display (Y page 295).
Changes in the outside temperature are dis-
played after a short delay. 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 analogue coolant temperature gauge is in
the instrument cluster on the right-hand side (Y page 34).
In the on-board computer in the Service Service
menu there is a digital coolant temperature
gauge (Y page 307).
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 120 †.
At high outside temperatures and when driv-
ing uphill, the coolant temperature may rise
to the end of the scale. Displays and operation
293On-board computer and displays Z

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 393).
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 If the coolant temperature is below 120 †, you can continue
driving 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 207).
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 120 †. 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 120 †. Display messages
333On-board computer and displays Z

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 defective power electronics (hybrid vehicles)
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 207).
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 to prevent it from rolling away (Y page 207).
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. 334
Display
messagesOn-board computer and displays