
SmartKey positions
SmartKeygTo remove the SmartKey
(shift the transmission to position P)1Power supply for some consumers, such
as the windshield wipers2Ignition (power supply for all consumers)
and drive position3To start the engine
Once the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. The indicator lamps of the low-beam
headlamps, high-beam headlamps, turn
signal lamps or front fog lamps only light up
if the low-beam headlamps, high-beam
headlamps, turn signal lamps or front fog
lamps are switched on. If an indicator lamp
does not light up when the ignition is switched
on, check it and replace it if necessary. If an
indicator lamp does not go out after starting
the engine or lights up while the vehicle is in
motion, see ( Y page 240).
If the SmartKey is in position 0 in the ignition
lock for an extended period of time, it can no
longer be turned in the ignition lock. The
steering is then locked. To unlock, remove the
SmartKey and reinsert it in the ignition lock.
The steering is locked when you remove the
SmartKey from the ignition lock.
XRemove the SmartKey when the engine is
switched off.
The battery may otherwise discharge.If you cannot turn the SmartKey in the ignition
lock, the vehicle battery may not be charged
sufficiently.XCheck the vehicle battery and charge if
necessary ( Y page 294).
or
XJump-start the vehicle ( Y page 296).
i
The 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.
KEYLESS-GO
Vehicles with KEYLESS-GO are equipped with
a SmartKey with an integrated KEYLESS-GO
function and a detachable Start/Stop button.
The Start/Stop button must be inserted in the
ignition lock and the SmartKey must be in the
vehicle.
Pressing the Start/Stop button several times
in succession corresponds to the different
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
immediately.
The Start/Stop button can be removed from
the ignition lock. Then you can insert the
SmartKey in the ignition lock.
i You do not have to remove the Start/Stop
button from the ignition lock when you
leave the vehicle. However, you should
always take the SmartKey with you when
leaving the vehicle. The vehicle can be
started with the Start/Stop button and the
electrical equipment can be operated while
the SmartKey is in the vehicle.
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Problems with the engineProblemPossible causes/consequences and M SolutionsThe 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.XTurn the SmartKey back to position 0 in the ignition lock before
the next attempt to start with the SmartKey.XBefore the next starting attempt with KEYLESS-GO: shut all open
vehicle doors so that the signals from the SmartKey may be
better received.
or
XPull the Start/Stop button out of the ignition.XUse the SmartKey to start the engine, (Y page 153) as external
radio signals cause KEYLESS-GO to malfunction. 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:
XConsult a qualified specialist workshop.The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the starter battery is too
weak or discharged.XJump-start the vehicle ( Y page 296).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.The starter motor was exposed to a thermal load that was too high.XAllow the starter motor to cool down for approximately two
minutes.XTry to start the engine again.
If the engine still does not start:
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Vehicles with automatic transmissionXApply the parking brake firmly.XShift the transmission to position P.
Using the SmartKey
XTurn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.
iThe SmartKey can only be removed if the
transmission is in position P.
Using KEYLESS-GO
XPress the Start/Stop button (Y page 151).
When the driver's door is closed, the Start/
Stop button is in position 1. When the
driver's door is opened, the Start/Stop
button moves to position 0. This
corresponds to removing the SmartKey.
If you attempt to turn off the engine when the
selector lever is not in position P, a warning
signal sounds.
Observe the messages in the multifunction
display.
iIn an emergency, you can turn off the
engine while the vehicle is in motion by
pressing and holding the Start/Stop button
for three seconds.
Parking brake
GWarning
Engaging the parking brake while the vehicle
is in motion can cause the rear wheels to lock
up. You could lose control of the vehicle and
cause an accident. In addition, the vehicle's
brake lights do not light up when the parking
brake is engaged.
GWarning!
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it with
you, and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. Children could
release the parking brake and/or shift the
automatic transmission out of park position
P, either of which could result in an accident
and/or serious personal injury.
XTo apply: depress parking brake ; firmly.
When the engine is running, the $ (USA
only) or J (Canada only) indicator lamp
lights up in the instrument cluster.
XTo release: depress the brake pedal and
keep it depressed.
XPull release handle :.
When the ignition is switched on or the
engine is running, the $ (USA only) or
J (Canada only) indicator lamp goes out
in the instrument cluster.
Parking up the vehicle
If you leave the vehicle parked up for longer
than four weeks, the battery may be damaged
by exhaustive discharge.
XDisconnect the battery or connect it to a
trickle charger.
iYou can obtain information about trickle
chargers from a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
If you leave the vehicle parked up for longer
than six weeks, the vehicle may suffer
damage as a result of lack of use.
XVisit a qualified specialist workshop and
seek advice.
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Changing lanes
If you wish to change to the passing lane (in
left-hand-drive vehicles, the passing lane is
the left-hand lane), DISTRONIC PLUS
supports you if:
R you are driving above 40 mph (60 km/h)
R DISTRONIC PLUS is maintaining the
distance to a vehicle in front
R you switch on the appropriate turn signals
R DISTRONIC PLUS does not detect a danger
of collision
If these conditions are met, your vehicle is
accelerated. Acceleration will be interrupted
if changing lanes takes too long or if the
distance between your vehicle and the
vehicle in front becomes too small.GWarning
DISTRONIC PLUS and Active Blind Spot Assist
are only aids designed to assist driving.
They do not relieve you of the responsibility
of paying attention. The driver remains fully
responsible for the vehicle's distance from
other vehicles, the vehicle's speed and for
braking in good time. Always pay attention to
traffic conditions and your surroundings.
Otherwise, you may fail to recognize dangers
in time, cause an accident and injure yourself
and others.
Stopping
GWarning
Never get out of the vehicle when DISTRONIC
PLUS is activated.
DISTRONIC PLUS must also never be
operated, activated or deactivated by a
passenger or from outside the vehicle.
DISTRONIC PLUS does not replace the
parking brake and must not be used for
parking.
The DISTRONIC PLUS braking effect is
canceled and the vehicle can start moving if:
R DISTRONIC PLUS is deactivated using the
cruise control lever.
R you accelerate.
R
there is a malfunction in the system or an
interruption in the power supply, e.g.
battery failure.
R the electrical system in the engine
compartment, the battery or the fuses are
tampered with.
R the battery is disconnected.
If you wish to leave the vehicle or park it,
deactivate DISTRONIC PLUS and secure the
vehicle against rolling away.
If DISTRONIC PLUS detects that the vehicle
in front is stopping, it brakes your vehicle until
it is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i Depending on the specified minimum
distance, your vehicle will come to a
standstill at a sufficient distance behind the
vehicle in front. The specified minimum
distance is set using the control on the
cruise control lever.
You will see a warning message in the
multifunction display if DISTRONIC PLUS is
activated and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the engine is switched off.
R the hood is opened.
Shift to 'P'XMove the selector lever to P to prevent the
vehicle from rolling away.
DISTRONIC PLUS is deactivated. The
warning message in the multifunction
display disappears.
The horn will also sound at regular intervals if
DISTRONIC PLUS is activated and you:
R switch the engine off, open the driver's
door and take off your seat belt
R open the hood
The sounding of the horn alerts you to the fact
that the vehicle has been parked while
DISTRONIC PLUS is still activated. The sound
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iIf depressing the brake pedal the first
time does not activate the HOLD function,
wait briefly and then try again.GWarning
The vehicle's brakes are applied when the
HOLD function is activated. For this reason,
deactivate the HOLD function if the vehicle is
to be set in motion by other means (e.g. in a
car wash or by towing).
Deactivating the HOLD function
The HOLD function is deactivated
automatically if:
R you accelerate and the transmission is in
position D or R.
R the transmission is in position P.
R you apply the brakes again with a certain
amount of pressure until HOLD disappears
from the multifunction display.
R you activate DISTRONIC PLUS.
GWarning
Never get out of the vehicle when the HOLD
function is activated.
The HOLD function must never be operated
or deactivated by a passenger or from outside
the vehicle.
The HOLD function does not replace the
parking brake and must not be used for
parking.
The braking effect of the HOLD function is
canceled and the vehicle could roll away if:
R the HOLD function is deactivated by
depressing the accelerator pedal or the
brake pedal.
R there is a malfunction in the system or an
interruption in the power supply, e.g.
battery failure.
R the electrical system in the engine
compartment, the battery or the fuses are
tampered with.
R the battery is disconnected.
If you leave the vehicle or park it, deactivate
the HOLD function and secure the vehicle
against rolling away.
You will see a warning message in the
multifunction display if the HOLD function is
activated and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the engine is switched off.
R the hood is opened.
Shift to 'P'XMove the selector lever to P to prevent the
vehicle from rolling away.
The HOLD function is deactivated. The
warning message in the multifunction
display disappears.
A horn will also sound at regular intervals if
the HOLD function is activated and you:
R switch the engine off, open the driver's
door and take off your seat belt
R open the hood
The sounding of the horn alerts you to the fact
that the vehicle has been parked while the
HOLD function is still activated. The tone
becomes louder if you attempt to lock the
vehicle. The vehicle is not locked until the
HOLD function is deactivated.
i If the engine has been switched off, it
cannot be started again until the HOLD
function has been deactivated.
If there is a malfunction in the system or
power supply while the HOLD function is
activated, the Brake Immediately message
is shown in the multifunction display.
Immediately depress the brake firmly until
the warning message in the multifunction
display goes out.
You can also shift the transmission to position
P . This deactivates the HOLD function.
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Display messagesPossible causes/consequences and M SolutionsPRE-SAFE
Function Currently
Limited See Oper.
ManualGRisk of accident
PRE-SAFE ®
Brake is temporarily inoperative if:
R the DISTRONIC PLUS cover in the radiator grill is dirty.
R the sensors in the bumpers are dirty.
R its function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is insufficient.
PRE-SAFE ®
Brake is operational again and the display message
disappears when:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects that the sensors are fully available again.
R the system is within the operating temperature range.
If the display message continues to be displayed:
XClean the DISTRONIC PLUS cover in the radiator grill
( Y page 282).XClean the bumpers ( Y page 282).XRestart the engine.XWait until the battery is sufficiently charged.PRE-SAFE
Functions Limited
See Operator's
ManualGRisk of accident
PRE-SAFE ®
Brake is faulty. BAS PLUS or the distance warning
signal may also have failed.
XVisit a qualified specialist workshop.A
Malfunction
Service RequiredGRisk of injury
Cabriolet: the roll bars are defective.
XVisit a qualified specialist workshop immediately.Check Child Seat
Pos.
See Operator's
ManualGRisk of injury
Vehicles with BabySmart™ (Canada only):
The BabySmart™ child seat is positioned incorrectly.
XInstall the child seat in the correct position.Display messages215On-board computer and displaysBA 207 USA, CA Edition B 2011; 1; 3, en-USd2sboikeVersion: 3.0.3.62010-05-20T10:38:09+02:00 - Seite 215Z

Display messagesPossible causes/consequences and M Solutions?The engine fan is faulty.XAt coolant temperatures below 248 ‡ (120 †), continue driving
to the next qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-start driving.#The battery is not being charged.
Possible causes are:
R a faulty alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XVisit a qualified specialist workshop.4
Check Engine Oil
At Next
Refueling Check
Engine Oil at Next
RefuelingThe engine oil level has dropped to a critical level.
A warning tone also sounds.XCheck the oil level ( Y page 273).XIf necessary, add the engine oil ( Y page 274).XHave the engine checked for leaks if engine oil has to be added
more often than usual.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
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Display messagesPossible causes/consequences and M Solutions+
Obtain a new keyThe SmartKey needs to be replaced.XVisit a qualified specialist workshop.+
Replace Key BatteryThe batteries of the KEYLESS-GO key are discharged.XChange the batteries ( Y page 77).+
Don't Forget Your
KeyThe display message is displayed for a maximum of 60 seconds
and is just a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.XTake the KEYLESS-GO key with you when leaving the vehicle.+
Key Not Detected
(red display message)The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XLocate the KEYLESS-GO key.The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
A warning tone also sounds.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XOperate the vehicle with the KEYLESS-GO key in the ignition
lock if necessary.+
Key Not Detected
(white display
message)The KEYLESS-GO key cannot be detected at present.XChange the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
XChange the location of the key with the KEYLESS-GO functions
in the vehicle.XOperate the vehicle with the KEYLESS-GO key in the ignition
lock if necessary.Display messages239On-board computer and displaysBA 207 USA, CA Edition B 2011; 1; 3, en-USd2sboikeVersion: 3.0.3.62010-05-20T10:38:09+02:00 - Seite 239Z