2014 MERCEDES-BENZ C-CLASS SALOON climate control

Automatic engine switch-off
The internal combustion engine is switched
off automatically if:
R the driver removes his foot from the accel-
erator pedal and a speed of 160 km/h is
not exceeded (Y page 280)
R the combustion engine and the transmis-
sion have reached operating temperature
R the driver's seat belt is fastened and the
driver's door is closed
R the driver only slightly depresses the accel-
erator pedal in order to, for example, main- tain the current speed for a limited distance
R the bonnet is closed and engaged properly
R the high-voltage battery is charged suffi-
ciently
R there are no faults in the hybrid system
The internal combustion engine will not be
switched off automatically, if:
R the self-diagnosis function of the engine
control unit is still active
R the climate control of the vehicle requires it
R the high-voltage battery is being charged
(Y page 274)
R automatic emissions tests are running
R the operating temperature of the engine,
transmission and catalytic converter has
not yet been reached
Automatic engine start
The internal combustion engine, which has
been automatically switched-off, starts auto-
matically in certain situations, when:
R the power demand from the driver via the
accelerator pedal is greater than the elec-
tric motor alone can provide
R the driver switches to drive program Sor S
+
R the driver has activated manual gearshift-
ing R
the charge level of the high-voltage battery
has reached the lower limit
R the settings of the automatic climate con-
trol require it, e.g. at external temperatures
above 30 †
Overrun mode
This operating mode is available in the speed
range below 160 km/h.
The combustion engine is switched off and is disconnected from the drive train.
The electric motor:
R simulates an overrun torque which is equiv-
alent to the overrun torque of the combus-
tion engine
R functions as a generator and produces the
necessary energy for the auxiliary consum- ers and charges the high-voltage battery
Extended overrun mode
Overrun mode allows you to increase the
vehicle range.
When the vehicle is in overrun operating
mode:
X Pull the right-hand steering wheel gearshift
paddle.
Energy recuperation is reduced to the min-
imal amount of energy required. The vehi-
cle rolls faster and further, e.g. on long and steep downhill gradients or while coasting
towards a set of traffic lights.
You can see the reduction in energy recuper-
ation in the electric motor CHARGE display
(Y page 272).
The "extended overrun" operating mode is
deactivated again if:
R the combustion engine starts
R you depress the brake pedal 280
Hybrid operationDriving and pa
rking

Display messages
Possible causes/consequences and
M
MSolutions &
Pre-entry climate Pre-entry climate
control (via key) control (via key)
available again available again
after engine start after engine start Hybrid vehicles: with the engine switched off, you have attempted
to switch on the pre-entry climate control more than twice.
X Let the engine run for ten seconds.
After running the engine, the pre-entry climate control is opera-
tional again. &
Pre-entry climate Pre-entry climate
control (via key) control (via key)
inoperative inoperative
HV
HVbat‐
bat‐
tery low
tery low Hybrid vehicles: the on-board voltage is too low.
The pre-entry climate control cannot be switched on.
X Drive for a considerable distance.
The battery charges. The pre-entry climate control is operational
again as soon as the on-board electrical system voltage is suf-
ficient. &
Function Function
available
available
again
again after
afterengine
engine
start
start Vehicles with BlueEFFICIENCY package: you have attempted to
switch on the pre-entry climate control (eHeat/eVent) more than
3 times with the engine switched off.
X Let the engine run for ten seconds.
After running the engine, the pre-entry climate control is opera- tional again. &
inoperative Bat‐ inoperative Bat‐
tery low tery low The on-board voltage is too low.
The auxiliary heating (Y
page 172) has switched itself off. The
auxiliary heating or pre-entry climate control (eHeat/eVent) can-
not be switched on.
X Drive for a considerable distance.
The battery charges. The auxiliary heating or the auxiliary cli-
mate control ("eHeat/eVent" function) is operational again as
soon as the on-board electrical system voltage is sufficient. &
inoperative inoperative
Refuel
Refuel
vehicle
vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot
be switched on (Y page 172).
X Refuel at the nearest filling station. &
inoperative See inoperative See
Owner's Man. Owner's Man. The auxiliary heating is temporarily malfunctioning or faulty.
X When the vehicle is on a level surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heat- ing, waiting several minutes between each attempt
(Y page 172).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. 348
Display
messagesOn-board computer and displays

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

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