Problem
Possible causes/consequences and
0050
0050Solutions The engine cannot be
started using the
SmartKey. The on-board voltage is too low.
X Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 343).
or
X Jump-start the vehicle (Y page 345).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the Start/
Stop button. The
SmartKey is in the vehi-
cle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The SmartKey battery is discharged or nearly discharged.
X Check the SmartKey battery (Y page 82) and replace it if nec-
essary (Y page 82).
If this does not work:
X Start your vehicle with the SmartKey in the ignition lock. There is interference from a powerful source of radio waves.
X Start your vehicle with the SmartKey in the ignition lock. You have lost a Smart-
Key. X
Have the SmartKey deactivated at a qualified specialist work-
shop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. 84
SmartKeyOpening and closing
remove the SmartKey. This function
remains active for five minutes or until you
open a door.
i Before opening or closing the side win-
dows, a check is carried out to see whether a valid SmartKey is in the vehicle, if:
R a side window switch is pressed or pulled
and
R the Start/Stop button is used instead of
the SmartKey in the ignition lock
and
R the engine is not running
This is carried out by means of a brief radio connection between the vehicle and the
SmartKey. Convenience opening
General notes You can ventilate the vehicle before you start
driving.
If the SmartKey is in close proximity to the
vehicle, the convenience opening function is
available.
To do this, the SmartKey is used to carry out
the following functions simultaneously:
R unlock the vehicle
R open the side windows
R open the panorama roof roller sunblind
R switch on the seat ventilation for the driv-
er's seat
Convenience opening X
Press and hold the 0036button until the
side windows are in the desired position.
The panorama roof roller sunblind opens.
X To interrupt convenience opening:
release the 0036button. Convenience closing feature
Important safety notes G
WARNING
When using the convenience closing feature,
parts of the body could be trapped in the clos- ing area when a side window is being closed. There is a risk of injury.
Observe the complete closing procedure
when the convenience closing feature is oper-
ating. Make sure that no body parts are in
close proximity during the closing procedure.
You can close the side windows and the roller sunblind for the panorama roof after you lock
the vehicle.
i Notes on the automatic reversing feature
for:
R the side window (Y page 94)
R the roller sunblind (Y page 97)
Using the SmartKey X
Press and hold the 0037button until the
side windows and the roller sunblind for the
panorama roof are fully closed.
X Make sure that all the side windows are
closed.
X To interrupt convenience closing:
release the 0037button.
Using KEYLESS-GO The SmartKey must be outside the vehicle. All
the doors must be closed. Side windows
95Opening and closing Z
Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
i Read the information on qualified special-
ist workshops (Y page 25). Correct driver's seat position
G
WARNING
You could lose control of your vehicle if you do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt before starting the engine. X
Observe the safety guidelines on seat
adjustment (Y page 103).
X Check whether you have adjusted seat 0087
properly (Y page 104).
When adjusting the seat, make sure that:
R you are as far away from the driver's air bag
as possible
R you are sitting in a normal upright position
R you can fasten the seat belt properly
R you have moved the backrest to an almost
vertical position
R you have set the seat cushion angle so that
your thighs are gently supported
R you can depress the pedals properly
X Check whether the head restraint is adjus-
ted properly.
When doing so, make sure that you have
adjusted the head restraint so that the back of your head is supported at eye level by the center of the head restraint.
X Observe the safety guidelines on steering
wheel adjustment (Y page 110).
X Make sure that steering wheel 0043is adjus-
ted properly (Y page 110).
When adjusting the steering wheel, make
sure that:
R you can hold the steering wheel with your
arms slightly bent
R you can move your legs freely
R you can see all the displays in the instru-
ment cluster clearly
X Observe the safety guidelines for seat belts
(Y page 44).
X Check whether you have fastened seat
belt 0044properly (Y page 46).
The seat belt should:
R fit snugly across your body
R be routed across the middle of your shoul-
der
R be routed in your pelvic area across the hip
joints 102
Correct driver's seat positionSeats, steering wheel and mirrors
Problems with the windshield wipers
Problem
Possible causes/consequences and
0050
0050Solutions The windshield wipers
are obstructed Leaves or snow, for example, may be obstructing the windshield
wiper movement. The wiper motor has been deactivated.
X Switch off the engine using the Start/Stop button and open the
driver's door.
X Remove the cause of the obstruction.
X Switch the windshield wipers back on. The windshield wipers
fail completely. The windshield wiper drive is malfunctioning.
X Select another wiper speed on the combination switch.
X Have the windshield wipers checked at a qualified specialist
workshop. The wiper motor has been deactivated.
X Switch off the engine using the Start/Stop button and open the
driver's door.
X Remove the cause of the obstruction.
X Switch the windshield wipers back on. Windshield wipers
129Lights and windshield wipers Z
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 immedi-
ately.
A check which periodically establishes a radio
connection between the vehicle and the
SmartKey determines whether a valid Smart- Key is in the vehicle. This occurs, for example, when starting the engine.
To start the vehicle without actively using the
SmartKey:
R the Start/Stop button must be inserted in
the ignition lock.
R the SmartKey must be in the vehicle.
R the vehicle must not be locked with the
SmartKey or KEYLESS-GO (Y page 79).
Do not keep the SmartKey:
R with electronic devices, e.g. a mobile
phone or another SmartKey
R with metallic objects, e.g. coins or metal
foil
R inside metallic objects, e.g. a metal case
This can affect the functionality of the Smart- Key.
If you lock the vehicle with the SmartKey's
remote control or with KEYLESS-GO, after a
short time:
R you will not be able to switch on the ignition
with the Start/Stop button.
R you will not be able to start the engine with
the Start/Stop button until the vehicle is
unlocked again.
If you lock the vehicle centrally using the but-
ton on the front door (Y page 85), you can
continue to start the engine with the Start/
Stop button.
The engine can be turned off while the vehicle is in motion by pressing and holding the
Start/Stop button for approximately three
seconds. This function operates independ-
ently of the ECO start/stop automatic engine switch-off function. SmartKey positions with the Start/Stop
button
0043
Start/Stop button
0044 Ignition lock
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 280).
If Start/Stop button 0043has not yet been
pressed, this corresponds to the SmartKey
being removed from the ignition.
X To switch on the power supply: press
Start/Stop button 0043once.
The power supply is switched on. You can
now activate the windshield wipers, for
example.
The power supply is switched off again if:
R the driver's door is opened and
R you press Start/Stop button 0043twice when
in this position
X To switch on the ignition: press Start/
Stop button 0043twice.
The ignition is switched on.
The ignition is switched off when:
R the driver's door is opened and
R you press Start/Stop button 0043once when
in this position 148
DrivingDriving an
d parking
0087
Start/Stop button USA
0085 Start/Stop button Canada
Removing the Start/Stop button
You can remove the Start/Stop button from
the ignition lock and start the vehicle as nor-
mal using the SmartKey.
It is only possible to switch between Start/
Stop button mode and SmartKey operation
when the transmission is in position P.
X Remove Start/Stop button 0043from ignition
lock 0044.
You do not have to remove the Start/Stop
button from the ignition lock when you leave
the vehicle. You should, however, always take the SmartKey with you when leaving the vehi-
cle. As long as the SmartKey is in the vehicle:
R the vehicle can be started using the Start/
Stop button
R the electrically powered equipment can be
operated 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 During a cold start, the engine runs at higher
speeds to enable the catalytic converter to
reach its operating temperature. The sound of
the engine may change during this time. Driving
149Driving and parking Z
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 Before attempting to start the engine again, turn the SmartKey
in the ignition back to position 0or 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 149). 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 345).
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 Try to start the engine again.
If the engine still does not start:
X Consult a qualified specialist workshop. 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.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture gage 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 322). Observe the warning
notes as you do so and add coolant if necessary. 154
DrivingDriving and parking
Problems with the transmission
Problem
Possible causes/consequences and
0050
0050Solutions The transmission has
problems shifting gear. The transmission is losing oil.
X Have the transmission checked at a qualified specialist work-
shop immediately. The acceleration ability
is deteriorating.
The transmission no
longer changes gear. The transmission is in emergency mode.
It is only possible to shift into
secondgear and reverse gear.
X Stop the vehicle.
X Shift the transmission to position P.
X Switch off the engine.
X Wait at least ten seconds before restarting the engine.
X Shift the transmission to position Dor R.
If D is selected, the transmission shifts into secondgear; ifRis
selected, the transmission shifts into reverse gear.
X Have the transmission checked at a qualified specialist work-
shop immediately. Transfer case
! Performance tests may only be carried
out on a 2-axle dynamometer. The brake
system or transfer case could otherwise be
damaged. Contact a qualified specialist
workshop for a performance test.
! To prevent ESP ®
from intervening, the
ignition must be switched off (SmartKey or
the Start/Stop button in position 0or 1) if:
R the electric parking brake is being tested
on a brake dynamometer.
R the vehicle is being towed with only one
axle raised (not permitted for vehicles
with 4MATIC).
The brake system could otherwise be dam-
aged.
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always trans- mitted to both axles. Refueling
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, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before refueling. G
WARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury.
You must make sure that fuel does not come into contact with your skin, eyes or clothing
and that it is not swallowed. Do not inhale fuel
vapors. Keep fuel away from children. Refueling
163Driving and parking
Z