
Problem Possible causes/consequences and
0050
0050Solutions The engine can no
longer 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 564).
or
X Jump-start the vehicle (Y page 565).
or
X Consult a qualified specialist workshop. The engine can no
longer be started using
KEYLESS-GO. The
SmartKey is in the
vehicle. The vehicle is locked.
X
Unlock the vehicle and try to start the vehicle again. There is interference from a powerful source of radio waves.
X
Start your vehicle with the SmartKey in the ignition lock. Doors
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 shift the automatic transmission out of
parking position P.
R shift the manual transmission into neutral.
R starting 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
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. 88
DoorsOpening and closing

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
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle. Unlocking and opening doors from
the inside
! The side windows will not open/close if
the battery is discharged or if the side
windows have iced up. It will then not be
possible to close the door. Do not attempt
to force the door closed. You could
otherwise damage the door or the side
window.
You can open a door from inside the vehicle
even if it has been locked.
If the vehicle was previously locked with the
SmartKey or with KEYLESS-GO, opening the
vehicle from the inside will activate the anti-
theft alarm system. Switch off the alarm
(Y page 79). X
Pull door handle 0044.
If the door is locked, locking knob 0043pops
up. The door is unlocked and can be
opened.
i When a door is opened, the side window
on that side opens slightly. When the door
is closed, the side window closes again. Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside. For example, you can unlock
the front-passenger door from the inside or
lock the vehicle before you pull away. X
To unlock: press button 0043.
X To lock: press button 0044.
If the front-passenger door is closed, the
vehicle locks.
The central locking/unlocking button does
not lock or unlock the fuel filler flap or the
stowage compartments, such as the glove
box. Doors
89Opening and closing Z

X
Turn the mechanical key back to position
0047 and remove it.
X Insert the mechanical key into the
SmartKey.
i When you lock the vehicle (Y page 91),
the trunk is also locked. Trunk emergency release
You can unlock the trunk lid from the inside
with the emergency release button. X
Press emergency release button 0043briefly.
The trunk lid unlocks and opens slightly.
X Push the trunk lid upwards to open it
completely.
The trunk lid can be unlocked with the trunk
lid emergency release when the vehicle is
stationary or while driving.
The trunk lid emergency release does not
unlock the trunk lid if the battery is
disconnected or discharged.
Trunk lid emergency release light:
R emergency release button 0043flashes for
30 minutes after the trunk lid is opened
R emergency release button 0043flashes for
60 minutes after the trunk lid is closed Side windows
Important safety notes
G
WARNING
While opening the side windows, body parts
could become trapped between the side
window and the door frame as the side
window moves. There is a risk of injury.
Make sure that nobody touches the side
window during the opening procedure. If
somebody becomes trapped, release the
switch or pull the switch to close the side
window again. G
WARNING
While opening the side windows, body parts
in the closing area could become trapped.
There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure. If
somebody becomes trapped, release the
switch or press the switch to open the side
window again. G
WARNING
If children operate the side windows they
could become trapped, particularly if they are
left unsupervised. There is a risk of injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle. Side window reversing feature
The side windows are equipped with an
automatic reversing feature. If a solid object
blocks or restricts a side window during the
closing process, the side window opens again
automatically. However, the automatic
reversing feature is only an aid and does not
relieve you of the responsibility of paying
attention when closing a side window. Side windows
97Opening and closing Z

The system automatically switches down
from level 3to level 2after approximately
eight minutes.
The system automatically switches down
from level 2to level 1after approximately ten
minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
You can set the distribution of the heated
sections of the seat cushion and backrest
using COMAND (Y page 320).
X Make sure that the SmartKey is in position
1 or 2in the ignition lock.
X To switch on: press button0043repeatedly
until the desired heating level is set.
X To switch off: press button0043repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off.
Problems with the seat heating The seat heating has switched off
prematurely or cannot be switched on. The
vehicle's electrical system voltage is too low
because too many electrical consumers are
switched on.
X Switch off electrical consumers that you do
not need, such as the rear window
defroster or interior lighting.
X Once the battery is sufficiently charged,
switch on the seat heating again. Switching the seat ventilation on/off
Activating/deactivating The three blue indicator lamps in the buttons
indicate the ventilation level you have
selected.
X
Make sure that the SmartKey is in position
2in the ignition lock.
X To switch on: press button0043repeatedly
until the desired ventilation level is set.
X To switch off: press button0043repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
ventilation may switch off.
i If you open the roof with the SmartKey
(Y page 103), the seat ventilation of the
driver's seat switches on automatically and
the side windows open.
Problems with the seat ventilation The seat ventilation has switched off
prematurely or cannot be switched on. The
vehicle's electrical system voltage is too low
because too many electrical consumers are
switched on.
X
Switch off electrical consumers which you
do not need, such as the rear window
defroster or interior lighting. Seats
117Seats, steering wheel and mirrors Z

AIRSCARF
Activating/deactivating G
WARNING
When AIRSCARF is switched on, very hot air
can flow from the vents in the head restraints.
This could result in burns in the immediate
vicinity of the air vents. There is a risk of injury.
Reduce the heater output before it becomes
too hot. The AIRSCARF function warms the head and
neck area of vehicle occupants with warm air.
The warm air flows out of the holes in the head
restraints.
The three red indicator lamps in the button
indicate the heating level you have selected.
X Make sure that the SmartKey is in position
2in the ignition lock.
X To switch on: press button0043.
Three red indicator lamps in the button light
up. The blower starts up after a preheating
phase of seven seconds.
X Press button 0043repeatedly until the
desired heating level is set.
X To switch off: press button0043repeatedly
until all the indicator lamps go out.
i The blower continues running for seven
seconds to cool down the heating
elements.
i If the battery voltage is too low, AIRSCARF
may switch off. Steering wheel
Important safety notes
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,
steering wheel and mirror and fasten your
seat belt before starting the engine. G
WARNING
You can no longer steer the vehicle if the
steering wheel lock has been engaged. There
is a risk of an accident.
Always switch off the ignition when towing the
vehicle with a tow cable or a tow bar. Adjusting the steering wheel
electrically
0043
To adjust the steering wheel height
0044 To adjust the steering wheel position
(fore-and-aft adjustment)
i Further related subjects:
R EASY-ENTRY/EXIT feature
(Y page 119)
R Storing settings (Y page 123)118
Steering wheelSeats
, steering wheel and mirrors

00470063
Left-hand standing lamps
00480064 Right-hand standing lamps
00490060 Parking lamps, license plate and
instrument cluster lighting
004A0058 Automatic headlamp mode,
controlled by the light sensor
004B0058 Low-beam/high-beam headlamps
Even if the light sensor does not detect that
it is dark, the parking lamps and low-beam
headlamps switch on when the ignition is
switched on and the light switch is set to the
0058 position. This is a particularly useful
function in the event of rain and fog.
X To switch on the low-beam headlamps:
turn the SmartKey in the ignition lock to
position 2or start the engine.
X Turn the light switch to 0058.
The green 0058indicator lamp in the
instrument cluster lights up.
Parking lamps
! If the battery has been excessively
discharged, the parking lamps or standing
lamps are automatically switched off to
enable the next engine start. Always park
your vehicle safely and sufficiently lit
according to legal standards. Avoid the
continuous use of the 0060parking lamps
for several hours. If possible, switch on the
0064 right or the 0063left standing lamp. 00470063
Left-hand standing lamps
00480064 Right-hand standing lamps
00490060 Parking lamps, license plate and
instrument cluster lighting
004A0058 Automatic headlamp mode,
controlled by the light sensor
004B0058 Low-beam/high-beam headlamps
X To switch on: turn the light switch to
0060.
The green 0060indicator lamp in the
instrument cluster lights up.
Standing lamps 00470063
Left-hand standing lamps
00480064 Right-hand standing lamps
00490060 Parking lamps, license plate and
instrument cluster lighting
004A0058 Automatic headlamp mode,
controlled by the light sensor
004B0058 Low-beam/high-beam headlamps
Switching on the standing lamps ensures the
corresponding side of the vehicle is
illuminated. 128
Exterior lightingLights and windshield wipers

0085
003D Switches the right-hand reading
lamp on/off
0083 Switches the automatic interior lighting
control on Interior lighting control
General notes In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
unless the SmartKey is in position
2in the
ignition lock.
Automatic interior lighting control Overhead control panel
0043
003D To switch the left-hand reading lamp
on/off
0044 004A To switch the interior lighting on
0087 0033 To switch the interior lighting/
automatic interior lighting control off
0085 003D To switch the right-hand reading
lamp on/off
0083 To switch the automatic interior lighting
control on
X To switch on: set the switch to center
position 0083.
X To switch off: set the switch to the 0033
position. The interior lighting automatically switches
on if you:
R
unlock the vehicle
R open a door
R remove the SmartKey from the ignition lock
The interior light is activated for a short while
when the SmartKey is removed from the
ignition lock. You can activate this delayed
switch-off using the on-board computer
(Y page 238).
Manual interior lighting control X
To switch the interior lighting on: set the
switch to the 004Aposition.
X To switch the interior lighting off: set the
switch to the 0033or (if the door is closed)
to the center position.
X To switch the reading lamps on/off:
press the 003Dbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Lock and then unlock the vehicle using the
SmartKey. Replacing bulbs
G
DANGER
Xenon bulbs carry a high voltage. You can get
an electric shock if you remove the cover of
the Xenon bulb and touch the electrical
contacts. There is a risk of fatal injury.
Never touch the parts or the electrical
contacts of the Xenon bulb. Always have work
on the Xenon bulbs carried out at a qualified
specialist workshop. Replacing bulbs
133Lights and windshield wipers Z

Problems with the rear window defroster
Problem Possible causes/consequences and
0050
0050Solutions The rear window
defroster has
deactivated
prematurely or cannot
be activated. The on-board voltage is too low because too many electrical
consumers are switched on.
X Switch off any consumers that are not required, e.g. reading
lamps, interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window
defroster can be activated again. Activating/deactivating air-
recirculation mode
General notes If you switch on air-recirculation mode, the
windows can fog up more quickly, in
particular at low temperatures. Only use air-
recirculation mode briefly to prevent the
windows from fogging up.
Activating/deactivating X
Turn the SmartKey to position 2in the
ignition lock (Y page 155).
X To activate: press the0072button.
The indicator lamp in the 0072button lights
up.
i Air-recirculation mode is automatically
activated at high levels of pollution or at
high outside temperatures. When air-
recirculation mode is activated
automatically, the indicator lamp in the
0072 button is not lit. Outside air is added after about
30 minutes.
X To deactivate: press the0072button.
The indicator lamp in the 0072button goes
out.
i Air-recirculation mode deactivates
automatically:
R after approximately five minutes at
outside temperatures below
approximately 41 ‡ (5 †)
R after approximately five minutes if
cooling with air dehumidification is
deactivated
R after approximately 30 minutes at
outside temperatures above
approximately 41 ‡(5 †) if the "Cooling
with air dehumidification" function is
activated Activating/deactivating the residual
heat function
General notes 150
Operating the climate control systemsClimate control