
Problems with PARKTRONIC
Problem Possible causes/consequences and
M SolutionsOnly the red segments
in the PARKTRONIC
warning
displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is
deactivated after
approximately
20 seconds, and the
indicator lamp in the
PARKTRONIC button
lights up. PARKTRONIC has malfunctioned and has switched off.
X
If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. Only the red segments
in the PARKTRONIC
warning
displays are lit.
PARKTRONIC is
deactivated after
approximately
20 seconds. The PARKTRONIC sensors are dirty or there is interference.
X
Clean the PARKTRONIC sensors ( Y page 304).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X
See if PARKTRONIC functions in a different location. Parking Guidance
Important safety notes G
WARNING
Parking Guidance is merely an aid and may
display parking spaces that are not suitable
for parking, for example:
R no-parking areas
R parking spaces with unsuitable surfaces
(road surface)
R driveways
R entrances and exits
Parking Guidance detects and measures
potential parking spaces while driving past.
Changes
to the parking space after this point
are not taken into account, for example if the
vehicle in front of or behind the parking space changes position or objects in the parking
space are moved.
Even when using Parking Guidance, you are
still responsible for driving carefully. If you
rely on Parking Guidance alone, you could
cause an accident and injure yourself and
others.
Safety
always remains your responsibility and
you must continue paying careful attention to
your immediate surroundings when parking
and maneuvering. G
WARNING
Objects located above the height range of
Parking Guidance will not be detected when
the
parking space is measured. These objects
are not taken into account when the parking
procedure is calculated, e.g. overhanging
loads, tail sections or loading ramps of goods 194
Driving systems
Driving and parking

Other status indicators of the
navigation system
R
O: you have reached the destination or an
intermediate destination.
R New Route... or Calculating Route:
calculating a new route
R Off Map or Off Mapped Road : the vehicle
position is outside the area of the digital
map (off-map position).
R No Route : no route could be calculated to
the selected destination. Audio menu
Selecting a radio station :
Waveband
; Station frequency with memory position
i Station ; is displayed with the station
frequency or station name. The memory
position is only displayed along with
station ; if this has been stored.
X Switch on the audio system or COMAND
and select Radio; see the separate
operating instructions.
X Press the = or ; button on the
steering wheel to select the Audio menu.
X To select a stored station: briefly press
the 9 or : button.
X To select a station from the station
list: press and briefly hold the 9
or : button.
If no station list is received:
X To select a station using the station
search: press and briefly hold the 9
or : button. i
For information on switching waveband
and storing stations; see the separate
operating instructions.
i SIRIUS XM satellite radio functions like a
normal radio.
For more information on satellite radio
operation, see the separate operating
instructions.
Operating audio player or audio media Display CD/DVD changer (example)
:
Current title
Audio data from various audio devices or
media can be played, depending on the
equipment installed in the vehicle.
X Switch on COMAND and activate audio
CD/DVD mode or MP3 mode; see the
separate operating instructions.
X Press the = or ; button on the
steering wheel to select the Audio menu.
X To select the next/previous track:
briefly press the 9 or : button.
X To select a track from the track list
(rapid scrolling): press and hold the
9 or : button until desired
track : has been reached.
If you press and hold 9 or :, the
rapid scrolling speed is increased. Not all
audio drives or data carriers support this
function.
If track information is stored on the audio
device or medium, the multifunction display
will show the number and title of the track.
The current track does not appear in audio
AUX mode (Auxiliary audio mode: external
audio source connected). Menus and submenus
219
On-board computer and displays Z

Display messages Possible causes/consequences and
M SolutionsPRE-SAFE
Inoperative See
Operator's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
Functions
Currently Limited
See Operator's
Manual
PRE-SAFE
®
Brake is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator grill and the bumper are dirty.
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 too low.
When the causes stated above no longer apply, the display
message disappears.
PRE-SAFE ®
Brake is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 167).
X Clean the sensors in the radiator grill and the bumper
(Y page 304).
X Restart the engine. PRE-SAFE
Functions Limited
See Operator's
Manual
PRE-SAFE
®
Brake is inoperative due to a malfunction. BAS PLUS
or the distance warning signal may also have failed.
X Visit a qualified specialist workshop. A
Malfunction
Service Required G
Risk of injury
Cabriolet: the roll bars are defective.
X Visit a qualified specialist workshop immediately.232
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsBlind Spot Assist
Currently
Unavailable See
Operator's Manual
or Active Blind
Spot Assist
Currently
Unavailable See
Operator's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily
inoperative. Possible causes are:
R
the sensors are dirty.
R function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
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.
The yellow 9 indicator lamps also light up in the exterior
mirrors.
When the causes stated above no longer apply, the display
message disappears.
Blind Spot Assist or Active Blind Spot Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 167).
X Clean the sensors ( Y page 304).
X Restart the engine. Blind Spot Assist
Inoperative or
Active Blind Spot
Assist Inoperative Blind Spot Assist or Active Blind Spot Assist is defective.
The yellow
9 indicator lamps also light up in the exterior
mirrors.
X Visit a qualified specialist workshop. Parking Guidance
Inoperative Parking Guidance is malfunctioning (
Y page 194).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop.244
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M SolutionsDISTRONIC PLUS
Currently
Unavailable See
Operator's Manual DISTRONIC PLUS is temporarily inoperative. Possible causes are:
R
function is impaired due to heavy rain or snow.
R the sensors in the radiator grill and the bumper are dirty.
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 too low.
A warning tone also sounds.
When the causes stated above no longer apply, the display
message disappears.
DISTRONIC is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 167).
X Clean the sensors in the radiator grill and the bumper
(Y page 304).
X Restart the engine. DISTRONIC PLUS
Inoperative DISTRONIC PLUS is defective.
BAS PLUS (Brake Assist PLUS) and PRE-SAFE
®
Brake may be
inoperative as well.
A warning tone also sounds.
X Visit a qualified specialist workshop. DISTRONIC PLUS
Passive You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X
Remove your foot from the accelerator pedal. DISTRONIC PLUS
- - - mph An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 177).246
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M SolutionsCorrect
Tire Pressure The tire pressure is too low in at least one of the tires, or the tire
pressure difference between the wheels is too great.
X
Check the tire pressures at the next opportunity (Y page 330).
X If necessary, correct the tire pressure.
X Restart the tire pressure monitor (Y page 332). TirePress.
Sensor(s) Missing There is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not displayed in the
multifunction display.
X
Have the faulty tire pressure sensor replaced at a qualified
specialist workshop. Tire Press. Monitor
Currently
Unavailable Due to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.
X
Drive on.
The
tire pressure monitor restarts automatically as soon as the
problem has been solved. h
Tire Press.
Warning Tire
Malfunction The tire pressure in one or more tires has dropped suddenly.
A warning tone also sounds.
G WARNING
If you drive with a flat tire, there is a risk of the following hazards:
R A flat tire affects the ability to steer or brake the vehicle.
R You could lose control of the vehicle.
R Continued
driving with a flat tire will cause excessive heat build-
up and possibly a fire.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers.
Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Y page 167).
X If there is a flat tire, inspect the tires ( Y page 308).250
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsÂ
Don't Forget Your
Key The display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.
X
Remember to take the KEYLESS-GO key with you when you
leave the vehicle. Â
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.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 167).
X Locate 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.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 167).
X Operate the vehicle with the SmartKey in the ignition lock. Â
Key Not Detected
(white display
message) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the SmartKey with the KEYLESS-GO
functions in the vehicle.
If the KEYLESS-GO key is still not detected:
X Operate the vehicle with the SmartKey in the ignition lock. Â
Key Detected in
Vehicle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. Display messages
255
On-board computer and displays Z

Synchronizing the rolling code
Your vehicle must be within reach of the
garage
door or exterior gate drive. Make sure
that neither your vehicle nor any persons/
objects are present within the sweep of the
door or gate.
Observe the safety notes when performing
the rolling code synchronization.
X Turn the SmartKey to position 2 in the
ignition lock.
X Press the programming button of the door
or gate drive (see the door or gate drive
operating instructions, e.g. under
"Programming of additional remote
controls").
i Usually, you now have
30seconds to
initiate the next step.
X Press previously programmed button ;,
= or ? of the integrated garage door
opener until the door closes.
The rolling code synchronization is then
complete.
Notes on programming the remote
control
Canadian radio frequency laws require a
"break" (or interruption) of the transmission
signals
after broadcasting for a few seconds.
Therefore, these signals may not last long
enough for the integrated garage door
opener. The signal is not recognized during
programming. Comparable with Canadian
law, some U.S. garage door openers are
designed to "time-out" in the same manner.
Proceed as follows:
R if you live in Canada
R if you have difficulties programming the
garage door opener (regardless of where
you live) when using the programming
steps X
Press and hold one of buttons ; to ? on
the integrated garage door opener.
After
a short time, indicator lamp : lights
up yellow.
X Release the button.
Indicator lamp : flashes yellow.
X Press button B of garage door remote
control A
for two seconds, then release it
for two seconds.
X Press button B again for two seconds.
X Repeat this sequence on button B of
remote control A until indicator lamp :
lights up green.
If indicator lamp : turns red, repeat the
process.
X Continue with the other programming
steps (see above).
Problems when programming
If you are experiencing problems
programming the integrated garage door
opener on the rear-view mirror, take note of
the following instructions:
R Check
the transmitter frequency of garage
door drive remote control A. This can
usually be found on the back of the remote
control.
The integrated garage door opener is
compatible with devices that have units
which operate in the frequency range of
280to 433MHz.
R Replace the batteries in garage door
remote control A. This increases the
likelihood that garage door remote control
A will transmit a strong and precise signal
to the integrated garage door opener in the
rear-view mirror.
R When programming, hold remote control
A at varying distances and angles from the
button that you are programming. Try
various angles at a distance between 2and
12 inches (5to 30 cm) or at the same angle
but at varying distances.
R If another remote control for the same
garage door drive is available, repeat the288
FeaturesStowage and features