Acceleration
Depending on the operating mode, pulling
away and driving under low load conditions
are performed:
R entirely by electric propulsion
R in combination with the internal combus-
tion engine
When accelerating under increased load or at full load, boost mode is utilised. The electric
motor supports the internal combustion
engine by providing additional torque when
the accelerator is depressed rapidly.
Overrun mode or braking
There are three possible operating modes
when the hybrid vehicle is decelerating:
R When coasting and decelerating, energy
recuperation is already taking place
(Y page 273). The electric motor functions
as an alternator and stores the recuperated energy in the high-voltage battery.
R When braking gently, the electric motor
increases the deceleration of the vehicle.
Energy recuperation is increased
(Y page 273). The electric motor functions
as an alternator and stores the recuperated energy in the high-voltage battery.
R Under heavy braking, the service brake is
also used to slow down the vehicle. Both
systems work together.
Driving in the city
Energy is recuperated during frequent decel-
eration and stopping in city traffic.
The vehicle can be driven by the electric
motor alone up to a speed of approximately
35 km/h, e.g.:
R while approaching a traffic light
R in stop-and-start traffic
The vehicle is driven by the electric motor
alone only when all conditions for the auto-
matic engine switch-off are fulfilled.
Further information on the automatic engine
switch-off (Y page 283). Driving on inter-urban roads
Three phases are possible when driving on
inter-urban roads:
R rapid acceleration (boost mode)
R constant energy consumption
R energy recuperation
Depending on the characteristics of the
route, there may be a lot of recuperated
energy available. This reduces consumption
and emissions.
Driving on the motorway
When driving on a motorway, the following
have a particularly positive effect on fuel con- sumption and emissions:
R the decrease in wasted power when using
recuperative braking
R the decrease in wasted power in overrun
mode when the combustion engine is
switched off
Manoeuvring and turning
The hybrid drive makes it possible to manoeu-
vre and turn solely using the electric motor.
ECO start/stop function General notes
The ECO start/stop function switches the
internal combustion engine off automatically
when the vehicle stops moving and at high
speeds (Y
page 283).
All vehicle systems remain active, e.g. the
automatic climate control.
The ECO start/stop function is only available
in drive programs C,Eand I. Electric-only
operation is only possible in drive programs C
and E. 282
Hybrid operationDriving and pa
rking
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 283)
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 277)
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 275).
The "extended overrun" operating mode is
deactivated again if:
R the combustion engine starts
R you depress the brake pedal Hybrid operation
283Driving and parking Z
Display messages
Possible causes/consequences and
M
MSolutions A The tailgate is open.
G WARNING
When the engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. ? The bonnet is open. A warning tone also sounds.
G WARNING
The open bonnet may then block your view when the vehicle is in
motion.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 211).
X Close the bonnet. Active bonnet mal‐ Active bonnet mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction or because it has already been triggered.
X Visit a qualified specialist workshop. C C At least one door is open. A warning tone also sounds.
X Close all doors. j
Check trailer Check trailer
hitch lock hitch lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
G WARNING
If the ball coupling is not engaged, the trailer may come loose.
There is a risk of an accident. X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 211).
X Engage the trailer coupling's ball coupling in the end position
(Y page 288). &
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. Display
messages
349On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions &
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 176) 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 176).
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 176).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. 350
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
longer. 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" 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 420).
Consult a Mercedes-Benz Service Centre if
you wish to leave your vehicle parked up for a
long period of time. Battery (vehicle)
419Breakdown assistance Z
Always keep service products out of the reach
of children. 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.
Tank capacity The total capacity of the fuel tank may vary,
depending on the vehicle equipment.
Model Total capacity
C 400 4MATIC
66.0 l
C 300 BlueTEC Hybrid
50.0 l
All other models
41.0 l
or
66.0 l Service products and capacities
471Technical data Z
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
at shorter intervals. More information
about the interval for oil change can be
obtained from any qualified specialist
workshop.
Usually you will find information about the
fuel grade on the pump. If you cannot find the
label on the petrol pump, ask the filling sta-
tion staff.
Information on refuelling (Y page 205).
Low outside temperatures
In winter months, diesel fuel with an improved
cold flow quality is available. In Europe, the
EN 590 standard defines various climate-
dependent temperature categories. Malfunc- tions can be avoided by refuelling with diesel
fuel that corresponds to the climatic specifi-
cations outlined in EN 590. At unusually low
outside temperatures, it is possible that the
flow characteristics of the diesel fuel could be insufficient. Accordingly, diesel fuel from
warmer areas may not be suitable for opera-
tion in colder climatic conditions. Service products and capacities
473Technical data Z