heating MERCEDES-BENZ C-CLASS SALOON 2014 Repair Manual

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 27). 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
! An active bonnet that had been triggered
must be repaired at a qualified specialist
workshop. 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. The active bonnet is
triggered by pyrotechnics. 390
Engine compartmentMaintenance and care

After washing the vehicle, brake carefully
while paying attention to the traffic conditions in order to restore full braking efficiency.
! 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
! Make sure:
R the side windows and sliding sunroof are
closed completely.
R the blower for the ventilation/heating is
switched off (OFF button is depressed).
R the windscreen wiper switch is at posi-
tion 0
R the 360° camera or reversing camera is
switched off.
The vehicle could otherwise be damaged.
! If the key is within the rear detection
range of KEYLESS-GO, the following situa-
tions, for example, could lead to the boot lid
opening unintentionally:
R using a car wash
R using a high-pressure cleaner
Make sure that the key is at least 3 m away
from the vehicle.
! Make sure that the automatic transmis-
sion is in neutral position Nwhen washing
your vehicle in a tow-through car wash. The
vehicle may otherwise be damaged.
R Operating with the key:
Do not remove the key from the ignition
lock. Do not open the driver's door when
the engine is switched off or at very low
speeds. Otherwise, when in transmission position Dor Rthe automatic transmis-
sion will automatically switch to park
position Pand block the wheels.
R Operating with the Start/Stop button: Do not open the driver's door when the
engine is switched off or at very low
speeds. Otherwise, when in transmission
position Dor Rthe automatic transmis-
sion will automatically switch to park
position Pand block the wheels.
Observe the following to make sure that the
automatic transmission stays in position N
neutral:
Operating with the key:
X Make sure the ignition is switched on.
X Make sure that the vehicle is stationary.
X Depress and hold the brake pedal.
X Select neutral N.
X Release the brake pedal.
X Release the electric parking brake, if nec-
essary.
X Switch off the ignition and leave the key in
the ignition lock.
Operating with the Start/Stop button:
X Make sure the ignition is switched on.
X Make sure that the vehicle is stationary.
X Depress and hold the brake pedal.
X Select park position P.
X Release the brake pedal.
X Remove Start/Stop button from ignition
lock (Y page 181).
X Insert the key into the ignition lock.
X Switch on the ignition.
X Depress and hold the brake pedal.
X Select neutral N.
X Release the brake pedal.
X Release the electric parking brake, if nec-
essary.
X Switch off the ignition and leave the key in
the ignition lock.
You can wash the vehicle in an automatic car
wash from the very start.
Wash off excess dirt before cleaning the vehi-
cle in an automatic car wash.
After using an automatic car wash, wipe off
wax from the windscreen and the wiper Care
397Maintenance and care Z

For more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
When you park the vehicle, remove the key if you do not require any electrical consumers.
The vehicle will then use very little energy,
thus conserving battery power.
Hybrid vehicles: if the battery charge is suf-
ficient, the high-voltage battery can also sup- ply the 12 V battery with energy. This only
happens if the battery charge of the 12 V bat-
tery requires this, e.g. after using electrical
consumers for an extended period with the
engine switched off. As the on-board voltage
is continuously monitored this can also be
performed when the engine is switched off.
The battery charge of the 12 V battery and the
on-board voltage are thereby kept stable for a
longer period. High-voltage battery - important
safety notes
Only hybrid vehicles are equipped with a high-
voltage battery. G
DANGER
The vehicle's high voltage electrical system is under high voltage. If you modify components
in the vehicle's high-voltage electrical system or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may be
damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Do not touch any high-voltage components
after an accident and never modify the vehi-
cle's high-voltage electrical system. Have the vehicle towed away after an accident and the vehicle's high-voltage electrical system
checked by a qualified specialist workshop. G
WARNING
In the event of a vehicle fire, the internal pres- sure of the high-voltage battery could exceeda critical value. In this case, flammable gas
escapes through a vent valve in the vehicle's
underbody. The gas can ignite. There is a risk
of injury.
Leave the danger area immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements. G
WARNING
If the housing of the high-voltage battery has
been damaged, electrolyte and gases may
leak out. These are poisonous and caustic.
There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
! Only charge the high-voltage battery in
the "Charging when stationary" operating
mode. Do not connect a battery charger to
the high-voltage battery. Otherwise, the
vehicle's high-voltage electrical system
could be damaged.
! Exhaustive discharge caused by the vehi-
cle standing idle for lengthy periods can
damage the high-voltage battery.
If the vehicle is idle for lengthy periods, run
it for a few minutes once every six weeks to
charge up the high-voltage battery.
During the charging process, switch off all
electrical consumers, e.g. the automatic
climate control or the seat heating.
If you wish to park your vehicle for several
weeks, ensure that the battery is at least 30 %
charged. If necessary, charge the high-volt-
age battery while stationary before parking
the vehicle (Y page 416).
Consult a Mercedes-Benz Service Centre if
you wish to leave your vehicle parked up for a
long period of time. Battery (vehicle)
415Breakdown assistance Z

Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R Vehicles with a petrol engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed using batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Automatic transmission: shift the transmission to position P.
X Manual transmission: depress the clutch pedal fully and shift to neutral.
X Make sure the ignition is switched off (Y page 181). All indicator lamps in the instrument
cluster must be off. When using the key, turn the key to position 0in the ignition lock and
remove it (Y page 181).
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Jump-starting
419Breakdown assistance Z

H
Environmental note
Dispose of service products in an environ-
mentally-responsible manner.
Service products include the following:
R fuels
R exhaust gas aftertreatment additives, e.g.
AdBlue ®
R lubricants (e.g. engine oil, transmission oil)
R coolant
R brake fluid
R windscreen washer fluid
R climate control system refrigerant
Components and service products must be
matched. Only use products recommended
by Mercedes-Benz. Damage which is caused
by the use of products which have not been
recommended is not covered by the
Mercedes-Benz warranty or goodwill ges-
tures. They are listed in this Mercedes-Benz
Owner's Manual in the appropriate section.
You can identify service products approved
by Mercedes-Benz by the following inscrip-
tions on the container:
R MB-Freigabe (e.g. MB-Freigabe 229.51)
R MB Approval (e.g. MB Approval 229.51)
Other designations or recommendations indi- cate a level of quality or a specification in
accordance with an MB Sheet Number (e.g.
MB 229.5). They have not necessarily been
approved by Mercedes-Benz.
Other identifications, for example:
R 0 W-30
R 5 W-30
R 5 W-40
Further information can be obtained from any
Mercedes-Benz Service Centre or on the
Internet at http://bevo.mercedes-benz.com. Fuel
Important safety notes G
WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion.
You must avoid fire, naked flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before refuelling. G
WARNING
Fuels are poisonous and hazardous to health. There is a danger of injury.
Do not swallow fuel or let it come into contact
with skin, eyes or clothing. Do not inhale fuel
vapours. Keep fuels out of the reach of chil-
dren.
If you or others come into contact with fuel,
observe the following:
R Wash the fuel off any affected areas of skin
with water and soap immediately.
R If you get fuel in your eyes, rinse them thor-
oughly with clean water immediately. Seek immediate medical attention.
R If fuel is swallowed, seek immediate medi-
cal attention. Do not induce vomiting.
R Change any clothing that has come into
contact with fuel immediately. Service products and capacities
469Technical data Z

octane rating of 91 RON/82 MON. This may
reduce engine performance and increase fuel consumption. Avoid driving at full throttle andsudden acceleration. Never refuel using fuel
with a lower RON/MON.
i In some countries, the available petrol
may not be sufficiently low in sulphur. This
fuel can temporarily produce unpleasant
odours, especially on short journeys. As
soon as sulphur-free fuel (sulphur content
<1 0 ppm) is used for refuelling, the odours
are reduced.
Information on refuelling (Y page 201).
C 200, C 250
! Only refuel using unleaded, sulphur-free
unleaded petrol with at least 95 RON/
85 MON that conforms to European stand- ard EN 228 or an equivalent specification.
You could otherwise impair engine output
or damage the emission control system.
i In some countries, the available petrol
may not be sufficiently low in sulphur. This
fuel can temporarily produce unpleasant
odours, especially on short journeys. As
soon as sulphur-free fuel (sulphur content
<1 0 ppm) is used for refuelling, the odours
are reduced.
Additives ! Operating the engine with fuel additives
added later can lead to engine failure. Do
not mix fuel additives with fuel. This does
not include additives for the removal and
prevention of residue build-up. Petrol must only be mixed with additives recommended
by Mercedes-Benz. Observe the instruc-
tions for use in the product description.
More information about recommended
additives can be obtained from any
Mercedes-Benz Service Centre.
Mercedes-Benz recommends that you use
fuel brands that have additives.
The quality of the fuel available in some coun- tries may not be sufficient. Residue could
build up in the injection system as a result. In this case, in consultation with a Mercedes-
Benz Service Centre, the petrol may be mixed
with the cleaning additive recommended by
Mercedes-Benz. Always observe the notes
and mixing ratios specified on the container.
Diesel Fuel grade
G
WARNING
If you mix diesel fuel with petrol, the flash
point of this fuel mixture is lower than that of pure diesel fuel. When the engine is running,
components in the exhaust system may over-
heat unnoticed. There is a risk of fire.
Never refuel with petrol. Never add petrol to
diesel fuel.
! When refuelling, only use diesel fuel that
conforms to the European standard EN 590
or is of equivalent quality. Fuel that does
not conform to EN 590 can lead to
increased wear as well as damage to the
engine and exhaust system.
! Do not use the following:
R marine diesel
R heating oil
R bio-diesel
R vegetable oil
R petrol
R paraffin
R kerosene
Do not mix such fuels with diesel fuel and
do not use any special additives. Other-
wise, engine damage may occur.
! Vehicles with diesel particle filters:
in
countries outside the EU, only use low sul-
phur Euro diesel with a sulphur content of
under 50 ppm. Otherwise, the emission
control system could be damaged.
! Vehicles without a diesel particle fil-
ter: in countries where only diesel fuel with
a high sulphur content is available, you will need to carry out your vehicle's oil change Service products and capacities
471Technical data Z

Do not inhale any ammonia vapours that may
be released. Only fill the AdBlue ®
tank in well-
ventilated areas.
Low outside temperatures AdBlue
®
freezes at a temperature of approx-
imately -11 †. The vehicle is delivered from
the factory equipped with an AdBlue ®
pre-
heating system. Winter operation can thus be guaranteed even at temperatures below
-11 †.
Additives !
Only use AdBlue ®
in accordance with ISO
22241. Do not use additives with AdBlue ®
and do not dilute AdBlue ®
with water. This
may destroy the BlueTEC exhaust gas after- treatment system.
Purity !
Impurities in AdBlue ®
(e.g. due to other
service products, cleaning agents or dust)
lead to:
R increased emission values
R damage to the catalytic converter
R engine damage
R malfunctions in the BlueTEC ®
exhaust
gas aftertreatment system
Assuring the purity of AdBlue ®
is particularly
important with respect to avoiding malfunc-
tions in the BlueTEC exhaust gas aftertreat-
ment system.
If AdBlue ®
is pumped out of the AdBlue ®
tank,
e.g. during repair work, do not use this fluid to refill the tank. The purity of the fluid can no
longer be guaranteed. Capacities The total capacity of the AdBlue
®
tank may
vary, depending on the vehicle equipment. Model Total capacity
All models
8.5 l
or
24.5 l Engine oil
General notes When handling engine oil, observe the impor-
tant safety notes on service products
(Y page 468).
The quality of the engine oil is decisive for the function and service life of an engine. After
extensive tests, Mercedes-Benz approves
engine oils that correspond to the current
technical standard.
Therefore, only Mercedes-Benz approved
engine oils may be used in Mercedes-Benz
engines.
Further information on tested and approved
engine oils can be obtained from any
Mercedes-Benz Service Centre. Mercedes-
Benz recommends that you have the oil
change carried out at a qualified specialist
workshop. Mercedes-Benz approval is indica-
ted on the oil container by the inscription "MB Approval" and the corresponding designa-
tion, e.g. MB Approval 229.51.
You can call up an overview of approved
engine oils on the Internet at
http://bevo.mercedes-benz.com by enter-
ing the designation, e.g. 229.5.
The table shows which engine oils have been
approved for your vehicle. Service products and capacities
473Technical data Z

Brake fluid
G
WARNING
The brake fluid continuously absorbs mois-
ture from the air. This results in the boiling
point of the brake fluid lowering. If the boiling
point of the brake fluid is too low, vapour
pockets may form when the brakes are sub-
jected to a heavy load. This would impair brak- ing efficiency. There is a risk of an accident.
Have the brake fluid renewed at the prescri-
bed intervals.
When handling brake fluid, observe the
important safety notes on service products
(Y page 468).
The brake fluid change intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.co m.
i Have the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Service
Booklet. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you top up
the antifreeze. Make sure that antifreeze is
not spilled next to the filler neck. Thoroughly
clean the antifreeze from components before
starting the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise 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 Inter-
net at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Service
Booklet.
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It is responsible
for the following:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operation will be approx-
imately 130 †.
The antifreeze/corrosion inhibitor concentra- tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -37 †.
R not exceed 55% (antifreeze protection
down to -45 †). Heat will otherwise not be
dissipated as effectively.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in accord-
ance with
MB Specifications for Service Products 310.1
.
The coolant is checked at every maintenance interval at a qualified specialist workshop.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures Service products and capacities
475Technical data Z