2018 MERCEDES-BENZ C CLASS engine overheat

GWARNING
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.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
Roverheat and cause a fire
Rlose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
!Do not warm up the engine with the vehicle
stationary. Drive off immediately. Avoid high
engine speeds and driving at full throttle until
the engine has reached its operating temper-
ature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
!Mercedes-AMG vehicles: at low engine oil
temperatures below 68 ‡ (+20 †), the max-
imum engine speed is restricted in order to
protect the engine. To protect the engine and
maintain smooth engine operation, avoid driv-
ing at full throttle when the engine is cold.
Hybrid vehicles: It is essential to read the infor-
mation in the supplementary manual. Other-
wise, you may not recognize dangers.
Key positions
SmartKey
gTo remove the SmartKey
1Power supply for some consumers, such as
the windshield wipers
2Ignition (power supply for all consumers)
and drive position
3To start the engine
iThe SmartKey can be turned in the ignition
lock even if it is not the correct SmartKey for
the vehicle. The ignition is not switched on.
The engine cannot be started.
Vehicles with AIRPANEL: you can open the
shutters in the radiator trim by turning the
SmartKey to position 2in the ignition lock.
After approximately 120 seconds the shutters
open automatically. Further information on
opening and cleaning the shutters
(
Ypage 312).
Start/Stop button
General notes
When you insert the Start/Stop button into the
ignition lock, the system needs approximately
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 Smart-
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.
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
136Driving
Driving and parking

clean water. Seek medical assistance with-
out delay.
RIf fuel is swallowed, seek medical assis-
tance without delay. Do not induce vomit-
ing.
RImmediately change out of clothing which
has come into contact with fuel.
GWARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
Do not get into the vehicle again during the refu-
eling process. otherwise electrostatic charge
could build up again.
GWARNING
Vehicles with a diesel engine:
If you mix diesel fuel with gasoline, the flash
point is lower than that of pure diesel fuel.
When the engine is running, exhaust system
components could overheat without being
noticed. There is a risk of fire.
Never refuel with gasoline. Never mix gasoline with diesel fuel.
!Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the ignition
if you accidentally refuel with the wrong fuel. Otherwise, the fuel will enter the fuel system.
Even small amounts of the wrong fuel could
result in damage to the fuel system and the
engine. Notify a qualified specialist workshop
and have the fuel tank and fuel lines drained
completely.
!Do not use gasoline to refuel vehicles with a
diesel engine. Do not switch on the ignition if
you accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel system.
Even small amounts of the wrong fuel could
result in damage to the fuel system and the
engine. The repair costs are high. Notify a
qualified specialist workshop and have the
fuel tank and fuel lines drained completely.
!Overfilling the fuel tank could damage the
fuel system.
!Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
!Use a filter when adding fuel from a fuel can.
The fuel lines and/or the fuel injection system
could otherwise be blocked by particles from
the fuel can.
If you overfill the fuel tank, fuel could spray out
when the fuel pump nozzle is removed.
For further information on fuel and fuel quality
(
Ypage 361).
Refueling
General information
Pay attention to the important safety notes
(Ypage 155).
All vehicles except PLUG-IN HYBRID vehi-
cles: if you unlock or lock the vehicle from the
outside, the fuel filler flap also unlocks or locks.
PLUG-IN HYBRID vehicles: the pressure in the
fuel tank must be released before refueling (see
Digital Operator's Manual).
The position of the 8fuel filler cap is dis-
played on the instrument cluster. The arrow next
to the filling pump indicates the side of the vehi-
cle.
Opening the fuel filler flap
:To open the fuel filler flap
;To insert the fuel filler cap
=Tire pressure table
?Instruction label for fuel type to be refueled
156Refueling
Driving and parking

The ECO display consists of three sections, with
an inner and outer area. The sections corre-
spond to the following three categories:
:Acceleration(evaluation of all accel-
eration processes):
Rthe outer area fills up and the inner area lights up green: moderate
acceleration, especially at higher
speeds
Rthe outer area empties and the
inner area is gray: sporty acceler-
ation
;Coasting (evaluation of all decelera-
tion processes):
Rthe outer area fills up and the inner area lights up green: anticipatory
driving, keeping your distance and
early release of the accelerator.
The vehicle can coast without use
of the brakes.
Rthe outer area empties and the
inner area is gray: frequent heavy
braking
=Constant (continuous evaluation
over the entire journey):
Rthe outer area fills up and the inner area lights up green: constant
speed and avoidance of unneces-
sary acceleration and deceleration
Rthe outer area empties and the
inner area is gray: fluctuations in
speed
The three inner areas display the current driving
style and light up green as a result of a particu-
larly economical driving style. Depending on thedriving situation, up to two areas may light up
simultaneously.
At the beginning of the journey, the three outer
areas are empty and fill up as a result of eco-
nomical driving. A higher level indicates a more
economical driving style. If the three outer areas
are completely filled at the same time, the driver
has adopted the most economical driving style
for the selected settings and prevailing condi-
tions. 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
does not
indicate a fixed consumption reduction. In addition to driving style, the actual consump-
tion is affected by other factors, such as:
Rload
RTire pressure
RCold start
RChoice of route
RActive electrical consumers
These factors are not included in the ECO dis-
play.
An economical driving style specially requires
driving at moderate engine speeds.
Achieving a higher value in the categories
"Acceleration" and "Constant":
Robserve the gearshift recommendations
Rdrive using drive program E
On long journeys at a constant speed, e.g. on the
highway, only the outer area for "constant" will
change.
The ECO display summarizes 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. On lon- ger journeys, there are fewer changes. For more
marked changes, perform a manual rest
(
Ypage 216).
For further information on the ECO display, see
(
Ypage 215).
Braking
Important safety notes
GWARNING
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.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients
!On long and steep gradients, you must
reduce the load on the brakes by shifting to a
lower gear in good time. This allows you to
take advantage of the engine's braking effect.
This helps you to avoid overheating the
brakes and wearing them out excessively.
166Driving tips
Driving and parking

When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage is not covered by the Mercedes-Benz war-
ranty.
Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads
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 the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance.
RIn order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
!Vehicles with 4MATIC: function or per-
formance tests may only be carried out on a 2-
axle dynamometer. If you wish to operate the
vehicle on such a dynamometer, please con-
sult a qualified specialist workshop in
advance. You could otherwise damage the
drive train or the brake system.
!Vehicles with 4MATIC: the ESP®system
operates automatically. If the electric parking
brake is tested on a brake dynamometer, the
engine and ignition must be switched off: turn
the SmartKey in the ignition lock to position
u or1 or press the Start/Stop button
repeatedly in accordance with the given
SmartKey positions.
Braking triggered automatically by ESP
®may
cause severe damage to the brake system.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular intervals.
Information on BAS (Brake Assist System)
(
Ypage 66) and Active Brake Assist with cross-
traffic function (Ypage 73).
Driving tips167
Driving and parking
Z

Winter driving
GWARNING
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.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
GDANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon monoxide (CO) may enter the vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open a
window on the side of the vehicle that is not
facing into the wind.
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Drive particularly carefully on slippery road sur-
faces. Avoid sudden acceleration, steering and
braking maneuvers. Do not use cruise control or
Distance Pilot DISTRONIC.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
XShift the transmission to position i.
The outside temperature indicator is not
designed to serve as an ice-warning device and is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freezing
point do not guarantee that the road surface is
free of ice. The road may still be icy, especially in
wooded areas or on bridges. The vehicle could
skid if you fail to adapt your driving style. Always
adapt your driving style and drive at a speed to
suit the prevailing weather conditions.
You should pay special attention to road condi-
tions when temperatures are around freezing
point. For more information on driving with snow
chains, see (
Ypage 336).
For more information on driving with summer
tires, see (
Ypage 335).
Observe the notes i n the "Winter operation" sec-
tion (
Ypage 335).
Driving systems
Mercedes-Benz Intelligent Drive
Mercedes-Benz Intelligent Drive stands for inno-
vative driver assistance and safety systems
which enhance comfort and support the driver in
critical situations. With these intelligent co-ordi- nated systems Mercedes-Benz has set a mile-
stone 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 the vehi-
cle occupants and that of other road users.
Further information on driving safety systems
(
Ypage 65).
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. This is especially important if the
vehicle is laden. 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 make it appropriate to maintain a steady
speed for a prolonged period. You can store any
road speed above 20 mph (30 km/h).
Important safety notes
Cruise control can neither reduce the risk of an
accident if you fail to adapt your driving style nor
override the laws of physics. Cruise control can-
not take into account the road, traffic and
weather conditions. Cruise control is only an
aid. You are responsible for maintaining a safe
distance to the vehicle in front, for vehicle
Driving systems169
Driving and parking
Z

the cruise control lever up:or down ;to
the pressure point.
Every time the cruise control lever is pressed
up : or down ;the last speed stored is
increased or reduced.
XTo adjust the set speed in 5 mph incre-
ments (10 km/h increments): briefly press
the cruise control lever up :or down ;
beyond the pressure point.
Every time the cruise control lever is pressed
up : or down ;the last speed stored is
increased or reduced.
iCruise control is not deactivated if you
depress the accelerator pedal. If you acceler-
ate to overtake, cruise control adjusts the
vehicle's speed to the last speed stored after
you have finished overtaking.
Deactivating cruise control
There are several ways to deactivate cruise con-
trol:
XBriefly press the cruise control lever forward
=.
or
XBrake.
Cruise control is automatically deactivated if:
Ryou engage the electric parking brake
Ryou are driving at less than 20 mph (30 km/h)
RESP®intervenes or you deactivate ESP®
Ryou shift the transmission to position i
while driving
If cruise control is deactivated, a warning tone
sounds. You will see the Cruise Control Off
message in the multifunction display for approx-
imately five seconds. The message on the mul-
tifunction display disappears and the segments
on the speedometer go out.
iWhen you switch off the engine, the last
speed stored is cleared.
Distance Pilot DISTRONIC
General notes
Distance Pilot DISTRONIC regulates the speed
and automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehicles
are detected with the aid of the radar sensor
system. Distance Pilot DISTRONIC brakes auto-
matically so that the set speed is not exceeded. Change into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden. 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 wear-
ing too quickly.
If Distance Pilot DISTRONIC detects that there is a risk of a collision, you will be warned visually
and acoustically. Without your intervention, Dis-
tance Pilot DISTRONIC cannot prevent a colli-
sion. An intermittent warning tone will then
sound and the distance warning lamp will light
up in the instrument cluster. Brake immediately in order to increase the distance to the vehicle in
front or take evasive action provided it is safe to
do so.
Distance Pilot DISTRONIC operates in the range
between 0 mph (0 km/h) and 120 mph
(200 km/h).
Do not use Distance Pilot DISTRONIC whi
le driv-
ing on roads with steep gradients.
Since Distance Pilot DISTRONIC transmits radar
waves, it can resemble the radar detectors of
the responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked about this.
iUSA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the equipment.
iCanada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device
will void any warranties, and is not permitted.
Do not tamper with, alter, or use in any no
n-
approved way.
Driving system s171
Driving an d parking
Z

Tachometer
!
Do not drive in the overrevving range, as this
could damage the engine.
The red band in the tachometer 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 condi-
tions when temperatures are around freezing
point.
Bear in mind that the outside temperature dis-
play indicates the temperature measured and
does not record the road temperature.
The outside temperature display is in the multi-
function display (
Ypage 212).
Changes in the outside temperature are dis-
played after a short delay.
Coolant temperature gauge
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
!If the coolant temperature is too high, a dis-
play message is shown.
If the coolant temperature display is in the
area marked in red, do not continue driving.
Otherwise, the engine will be damaged.
The coolant temperature gauge is in the lower
section of the tachometer (
Ypage 37).
Under normal operating conditions and at the
correct coolant level, the display may rise to the
red mark.
Operating the on-board computer
:Multifunction display
;Right control panel
=Left control panel
XTo activate the on-board computer: switch
on the power supply.
You can control the multifunction display and
the settings in the on-board computer using the
buttons on the multifunction steering wheel.
Left control panel
òROpens a menu list
9
:Press briefly:
RScrolls in lists
RSelects a menu or function
RIn the RadioorMediamenu:
opens a track or station list and
selects a station, an audio track or
a video scene.
RIn the Telephonemenu: switches
to the phone book and selects a
name or a telephone number
9
:Press and hold:
RScrolls quickly through all lists
RIn the RadioorMediamenu:
selects a station, audio track or
video scene using rapid scrolling
RIn the Telephonemenu: starts
rapid scrolling if the phone book is
open
Displays an doperation211
On-boa rd computer and displays
Z

Engine
Display messagesPossible causes/consequences andMSolutions
+
CheckCoolantLevelSee Operator's Man‐ual
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.
XAdd coolant, observing the warning notes before doing so
(Ypage 306).
If you have to add coolant frequently:
XContact a qualified specialist workshop and have the engine cooling
system checked.
?The fan motor is malfunctioning.
XIf the coolant temperature is below the red marking in the coolant
temperature gauge, drive to the nearest qualified specialist work-
shop.
XAvoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-and-go traffic.
?
Coolant Too HotStop Vehicle TurnEngine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to catch
fire.
Steam from the overheated engine can also cause serious burns which
can occur just by opening the hood.
There is a risk of injury.
XPull over and stop the vehicle safely and switch off the engine, pay- ing attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 161).
XWait until the engine has cooled down.
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 display message goes out and
the coolant temperature gauge is below the red marking. Other-
wise, the engine could be damaged.
XPay attention to the coolant temperature gauge.
If the temperature increases again:
XVisit a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature gauge may rise to the red marking.
Display messages243
On-board computer and displays
Z