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X
To switch on the ignition: press Start/
Stop button 0043twice.
i The power supply is switched off again if:
R the driver's door is opened and
R you press Start/Stop button 0043once
when in this position.
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light up. If an indicator lamp does not go out afterstarting the engine or lights up while driving,
see (Y page 235). Starting the engine
Important safety notes G
WARNING
If children are left unsupervised in the vehicle, they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation. G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
! Do not depress the accelerator when
starting the engine.
General notes i
The catalytic converter is preheated for
up to 30 second s after a cold start. The
sound of the engine may change during this
time.
Automatic transmission X
Shift the transmission to position P.
The transmission position display in the
multifunction display shows P.
i You can also start the engine when the
transmission is in position N.
Starting procedure with the SmartKey i
To start the engine using the SmartKey
instead of KEYLESS-GO, pull the Start/
Stop button out of the ignition lock.
X Turn the SmartKey to position 3in the igni-
tion lock (Y page 133) and release it as
soon as the engine is running.
Using KEYLESS-GO to start the engine You can start the engine if a valid SmartKey
with the integrated KEYLESS-GO function is in
the vehicle. Always take the SmartKey with
you when leaving the vehicle, even if you only
leave it for a short time. Pay attention to the
important safety notes. Driving
135Driving an d parking Z
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i
The Start/Stop button can be used to
start the vehicle without inserting the
SmartKey into the ignition lock. The Start/
Stop button must be inserted in the ignition
lock and the SmartKey must be in the vehi-
cle.
X Depress the brake pedal and keep it
depressed.
X Press the Start/Stop button once
(Y page 134).
The engine starts. Pulling away
Automatic transmission G
WARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate.
i It is only possible to shift the transmission
from position Pto the desired position if
you depress the brake pedal. Only then is
the selector lever lock released.
X Depress the brake pedal and keep it
depressed.
X Shift the transmission to position Dor R.
X Release the parking brake (Y page 152).
X Release the brake pedal.
X Carefully depress the accelerator pedal.
! If a warning tone sounds and the
Release Park. Brake
Release Park. Brake message appears
in the multifunction display, the parking
brake is still applied. Release the parking
brake.
i The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down. You can open the doors from the inside at
any time.
You can also deactivate the automatic lock-
ing feature (Y page 203).
i Upshifts take place at higher engine
speeds after a cold start. This helps the
catalytic converter to reach its operating
temperature more quickly.
Hill start assist Hill start assist helps you when pulling away
forwards or in reverse on an uphill gradient. It
holds the vehicle for a short time after you
have removed your foot from the brake pedal. This gives you enough time to move your footfrom the brake pedal to the accelerator pedal
and to depress it before the vehicle begins to roll. G
WARNING
After a short time, hill start assist will no lon-
ger brake your vehicle and it could roll away.
There is a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
leave the vehicle when it is held by hill start
assist.
X Take your foot off the brake pedal.
The vehicle is then held for about a second.
X Pull away.
Hill start assist is not active if: R you are pulling away on a level road or on a
downhill gradient.
R the transmission is in position N.
R the parking brake is applied.
R ESP ®
is malfunctioning. ECO start/stop function
Introduction The ECO start/stop function switches the
engine off automatically if the vehicle is stop-
ped under certain conditions. 136
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The engine starts automatically when the
driver wants to pull away again. The ECO
start/stop function thereby helps you to
reduce the fuel consumption and emissions
of your vehicle.
Important safety notes G
WARNING
If the engine is switched off automatically and you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving. There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes C 250 and C 250 Sport
If the
00A7 symbol is shown in green in the
multifunction display, the ECO start/stop
function switches the engine off automati-
cally if the vehicle stops moving.
Every time you switch on the engine using the
SmartKey or the Start/Stop button, the ECO
start/stop function is activated.
If the ECO start/stop function has been man- ually deactivated (Y page 139) or a malfunc-
tion has caused the system to be deactivated, the 00A7 symbol is not displayed.
C 350 and C 350 4MATIC
If the engine has been switched off automat-
ically by the ECO start/stop function, the
00A7 symbol is shown in the multifunction
display.
Every time you switch on the engine using the SmartKey or the Start/Stop button, the ECO
start/stop function is activated.
Automatic engine switch-off C 250 and C 250 Sport
If the vehicle is braked to a standstill in
Dor N,
the ECO start/stop function switches off the engine automatically. The ECO start/stop function is operational
and the
00A7symbol is displayed in green in
the multifunction display, if:
R the indicator lamp in the ECO button is lit
green.
R the outside temperature is within the range
that is suitable for the system.
R the engine is at normal operating temper-
ature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
R the hood is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
If the conditions for automatic engine switch- off are not all fulfilled, the 00A7symbol is
shown in yellow.
i All of the vehicle's systems remain active
when the engine is stopped automatically.
i The HOLD function can be activated if the
engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic
stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
i The engine can be switched off automat-
ically a maximum of four times (first stop
and three subsequent stops) in succession.
The 00A7 symbol is shown in yellow in the
multifunction display after the engine has
been started automatically for the fourth
time. When the 00A7symbol is shown in
green in the multifunction display, auto-
matic engine switch-off is again possible. Driving
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C 350 and C 350 4MATIC
If the vehicle is braked to a standstill in
Dor N,
the ECO start/stop function switches off the engine automatically.
The ECO start/stop function is operational
when:
R the indicator lamp in the ECO button is lit
green.
R the outside temperature is within the range
that is suitable for the system.
R the engine is at normal operating temper-
ature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
R the hood is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
i All of the vehicle's systems remain active
when the engine is stopped automatically.
i The HOLD function can also be activated
if the engine has been switched off auto-
matically. It is then not necessary to con-
tinue applying the brakes during the auto-
matic stop phase. When you depress the
accelerator pedal, the engine starts auto-
matically and the braking effect of the
HOLD function is deactivated.
i The engine can be switched off automat-
ically a maximum of four times (first stop
and three subsequent stops) in succession. Automatic engine start C 250 and C 250 Sport
The engine starts automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button.
R in transmission position Dor Nthe brake
pedal is released and the HOLD function is not active.
R you depress the accelerator pedal.
R you engage reverse gear R.
R you move the transmission out of position
P.
R you unfasten your seat belt or open the
driver's door.
R the vehicle starts to roll.
R the brake system requires this.
R the temperature in the vehicle interior devi-
ates from the set range.
R the system detects moisture on the wind-
shield when the air-conditioning system is
switched on.
R the battery's condition of charge is too low.
i Shifting the transmission to position
P
does not start the engine.
i If you shift the transmission from
Rto D,
the ECO start/stop function is available
again once the 00A7symbol reappears in
green in the multifunction display.
C 350 and C 350 4MATIC
The engine starts automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button.
R in transmission position Dor Nthe brake
pedal is released and the HOLD function is not active.
R you depress the accelerator pedal.
R you engage reverse gear R.
R you move the transmission out of position
P.
R you unfasten your seat belt or open the
driver's door. 138
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R
the vehicle starts to roll.
R the brake system requires this.
R the temperature in the vehicle interior devi-
ates from the set range.
R the system detects moisture on the wind-
shield when the air-conditioning system is
switched on.
R the battery's condition of charge is too low.
i Shifting the transmission to position
P
does not start the engine.
Deactivating/activating the ECO start/
stop function C 250 and C 250 Sport
ECO button
X To deactivate: press button0043.
Indicator lamp 0044and the 00A7symbol in
the multifunction display go out.
X To activate: press button 0043.
Indicator lamp 0044lights up.
If all conditions for automatic engine
switch-off (Y page 137) are fulfilled, the
00A7 ECO symbol is shown in green in the
multifunction display.
If not all conditions for automatic engine
switch-off (Y page 137) are fulfilled, the
00A7 ECO symbol is shown in yellow in the
multifunction display.
If this is the case, the ECO start/stop func- tion is not available.
Conditions for the automatic engine
switch-off (Y page 137). If indicator lamp
0044is off, the ECO start/stop
function has been deactivated manually or as the result of a malfunction. The engine will
then not be switched off automatically when
the vehicle stops.
C 350 and C 350 4MATIC ECO button
X To switch off: press button0043.
Indicator lamp 0044goes out.
X To switch on: press button0043.
Indicator lamp 0044lights up.
If the indicator lamp on the ECO button is off, the ECO start/stop function has been deac-
tivated manually or as the result of a mal-
function. Driving
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Problems with the engine
Problem
Possible causes/consequences and
0050
0050Solutions The engine does not
start. The starter motor
can be heard. R
There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.
X Turn the SmartKey back to position 0in the ignition lock before
attempting to start the engine again.
or
X Press the Start/Stop button repeatedly until all indicator lamps
in the instrument cluster go out.
X Try to start the engine again (Y page 135). Avoid excessively
long and frequent attempts to start the engine as these will drain
the battery.
If the engine does not start after several attempts: X Consult a qualified specialist workshop. The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged.
X Jump-start the vehicle (Y page 294).
If the engine does not start despite attempts to jump-start it:
X Consult a qualified specialist workshop. The starter motor was exposed to a thermal load that was too high.
X Allow the starter motor to cool down for approximately two
minutes.
X Try to start the engine again.
If the engine still does not start:
X Consult a qualified specialist workshop. 140
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Problem
Possible causes/consequences and
0050
0050Solutions The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it. The coolant tempera-
ture gauge shows a
value above 248 ‡
(120 †). The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 275). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate. G
WARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parking
brake. Selector lever
Overview of transmission positions Example: selector lever
005D
Park position with selector lever lock
005E Reverse gear
005C Neutral
005B Drive Automatic transmission
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Transmission position and drive pro-
gram display 0043
Transmission position display
0044 Drive program display
The current position of the selector lever is
shown by the indicators next to the selector
lever.
The indicators light up when the SmartKey is inserted into the ignition lock. The indicators go out when the SmartKey is removed from
the ignition lock. Transmission positions
0045 Park position
Do not shift the transmission into
position
P(Y page 151) unless the
vehicle is stationary. The parking
lock should not be used as a brake when parking. Always apply the
parking brake in addition to the
parking lock in order to secure the
vehicle.
The SmartKey can only be removedif the transmission is in position P.
If the SmartKey is removed from
the ignition lock, the selector lever
is locked.
If the vehicle electronics are mal-
functioning, the selector lever may be locked in position P. To release
a locked selector lever, see "Man-
ual override of parking lock"
(Y page 148). 0046 Reverse gear
Only shift the transmission to
R
when the vehicle is stationary. 142
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d parking