
You should always steer, brak
eoraccelerate
yourself, in particula rifwarned by Lane
Keeping Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an acciden tnor override the laws of physics.
Lane Keeping Assist cannot take into account
the road, traffic and weather conditions. Lane
Keeping Assist is merely an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time and for staying in your lane.
The Lane Keeping Assist does not keep the
vehicle in the lane.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to
insufficien tillumination of the road, or due
to snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflections (e.g .when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R there are no, several or unclear lane
markings for a lane, e.g. in areas with road
construction work
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are strong shadows cast on the lane
Switching on Lane Keeping Assist
X Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard or
Adaptive (Y
page 242).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected, the lines in the assistance graphics display
(Y
page 240) are shown in green. Lane
Keeping Assist is ready for use.
Standard
If Standard is selected, no warning vibration
occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
Adaptive
When Adaptive is selected, no warning
vibration occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a
highway.
R the system recognizes solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend. 224
Driving systemsDriving and parking

Active Lane Keeping Assist
General notes
Active Lane Keeping Assis
tmonitors the area
in front of your vehicle by means of camera
system 0002at the top of the windshield.
Various different areas to the front, rear and
side of your vehicle are also monitored with
the aid of the radar sensor system. Active
Lane Keeping Assist detect slane markings on
the road and can warn you before you leave
your lane unintentionally. If you do no treact
to the warning, a lane-correcting application
of the brakes can bring the vehicle back into
the original lane.
This function is available in the range between
40 mph and 120 mph (60 km/h and
200 km/h).
For Active Lane Keeping Assist to assist you
when driving, the radar sensor system must
be operational
Important safety notes
If you fail to adapt your driving style, Active
Lane Keeping Assist can neither reduce the
risk of acciden tnor override the laws of
physics. Active Lane Keeping Assist cannot
take account of road and weather conditions.
It may not recognize traffic situations. Active
Lane Keeping Assist is only an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time and for staying in your lane.
Active Lane Keeping Assist cannot
continuously keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
to the vehicle
R not give a warning or intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you.
Terminate the intervention in a non-critical
driving situation.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to
insufficient illumination of the road, or due
to snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflections (e.g. when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R the radar sensors in the front or rear
bumpers or the radiator grill are dirty, e.g.
obscured by snow
R there are no, several or unclear lane
markings for a lane, e.g. in areas with road
construction work
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are strong shadows cast on the lane 228
Driving systemsDriving and parking

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment 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
specialist workshops: (Y page 25).Important safety notes
G
WARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situatio npermits .Ifyou are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary. G
WARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
You must observe the legal requirements for
the country in which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the multifunction display
.You should therefore
make sure your vehicle is operating safely at
all times. Otherwise, a vehicle that is not
operating safely may cause an accident.
For an overview, see the instrument panel
illustration (Y page 31). Displays and operation
Coolant temperature display
G
WARNING
Opening the hood when the engine is
overheated or when there is a fire in the
engine compartment could expose you to hot
gases or other service products. There is a
risk of injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
! Adisplay message is shown if the coolant
temperature is too high.
If the coolant temperature is over
248 ‡(120 †), do not continue driving. The
engine will otherwise be damaged.
The coolan ttemperature gauge is in the
instrument cluster on the left-hand side
(Y page 31).
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †). Tachometer
! Do not drive in the overrevving range, as
this could damage the engine.
The red band in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protec tthe
engine when the red band is reached. 232
Displays and operationOn-board computer and displays

Display messages Possible causes/consequences and
0001 Solutions
000B(USA
only)
0005(Canada
only)
Check Brake Fluid Level There is no
tenough brake fluid in the brake fluid reservoir.
In addition, the 000B(USA only)/0005 (Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect may be impaired.
There is a ris kofanaccident.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 182).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. 0006
Check Brake Pad
Wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. 0008
mbrace Inoperative One or more main features of the mbrace system are
malfunctioning.
X
Have the mbrace system checked immediately at a qualified
specialist workshop. PRE-SAFE
Inoperative See
Operator's Manual Important functionso
f PRE-SAFE®
have failed .All other occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately. 252
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0001 Solutions
PRE-SAFE
Functions
Currently Limited
See Operator's
Manual PRE-SAFE
®
brake or Adaptive Brake Assist of COLLISION
PREVENTION ASSIST is temporarily not operational.
Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiato rgrill and the bumper are dirty.
R the rada rsensor 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 182).
X Clean the sensors in the radiator grill and the bumper
(Y page 323).
X Restart the engine. PRE-SAFE
Functions Limited
See Operator's
Manual PRE-SAFE
®
brake or Adaptive Brake Assist of COLLISION
PREVENTION ASSIST is not available due to a malfunction. BAS
PLUS or the distance warning signal may also have failed.
X Visit a qualified specialist workshop. 0013
Malfunction
Service Required G
Risk of injury
Cabriolet: the roll bars are defective.
X Visit a qualified specialist workshop immediately. 001D
SRS Malfunction
Service Required There is a malfunction in the SRS (Supplemental Restraint
System). The
001Dwarning lamp also lights up in the instrument
cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
For further information about SRS, see (Y page 43). Display messages
253On-board computer and displays Z

Display messages Possible causes/consequences and
0001 Solutions
Front Passenger
Airbag Disabled
See Operator's
Manual The front-passenger air bag is disabled during the journey, even
though:
R
an adult
or
R a person larger than a certain size is occupying the front-
passenger seat
If additional forces are applied to the seat, the system may
interpret the occupant's weight as lowe rthan it actually is.
G WARNING
The front-passenger air bag does not deploy during an accident.
There is an increased risk of injury.
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 182).
X Switch the ignition off.
X Have the occupant get out of the vehicle.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
X Observe the PASSENGER AIR BAG OFF indicator lamp in the
center console and the multifunction display and check the
following:
Seat unoccupied and ignition switched on:
R the PASSENGER AIR BAG OFF indicator lamp must light up and
remain lit. If the indicator lamp is on, OCS has disabled the front-
passenger air bag (Y page 50).
R the Front Passenger Airbag Enabled See Operator's Manual or
Front Passenger Airbag Disabled See Operator's Manual display messages must not be shown in
the multifunction display.
X Wait for a period of at least 60 seconds until the necessary
system checks have been completed.
X Make sure that the display messages do not appearint he
multifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the PASSENGER AIR BAG OFF indicator
lamp remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not fulfilled, the system is not operating
correctly.
X Visit a qualified specialist workshop immediately. Display messages
255On-board computer and displays Z

Display messages Possible causes/consequences and
0001 Solutions
Fo
rfurther information about the Occupan tClassification System,
see (Y page 50). Front Passenger
Airbag Enabled
See Operator's
Manual The front-passenger air bag is enabled during the journey, even
though:
R
a child, a small adult or an object weighing less than the
system's weight threshold is located on the front-passenger
seat
or
R the front-passenger seat is unoccupied
The system may detect objects or forces applying additional
weight on the seat.
G WARNING
The air bag may deploy unintentionally.
There is an increased risk of injury.
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 182).
X Switch the ignition off.
X Open the front-passenger door.
X Remove the child and the child restraint system fro mthe front-
passenger seat.
X Make sure that there are no objects on the seat adding to the
weight.
The system may otherwise detect the additional weight and
interpret the seat occupant's weight as greater than it actually
is.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
X Observe the PASSENGER AIR BAG OFF indicator lamp in the
center console and the multifunction display and check the
following:
Seat unoccupied and ignition switched on:
R the PASSENGER AIR BAG OFF indicator lamp must light up and
remain lit. If the indicator lamp is on, OCS (Occupant
Classification System) has disabled the front-passenger air bag
(Y page 50).
R the Front Passenger Airbag Enabled See Operator's Manual or
Front Passenger Airbag Disabled See Operator's Manual display messages must not be shown in
the multifunction display. 256
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0001 Solutions
X
Wait fo raperiod of at least 60 seconds until the necessary
system checks have been completed.
X Make sure that the display messages do not appear in the
multifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the PASSENGER AIR BAG OFF indicator
lamp remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not fulfilled, the system is not operating
correctly.
X Visit a qualified specialist workshop immediately.
For further information about the Occupant Classification System,
see (Y page 50). Lights
i Display messages about LEDs:
This display message will only appear if all LEDs have failed. Display messages Possible causes/consequences and
0001 Solutions
0002
Check Left
Cornering Light or
Check Right Cornering Light The left or right-hand cornering light is defective.
X
Visit a qualified specialist workshop. 0002
Check Left Low
Beam or
Check Right Low Beam The left or right-hand low-beam headlamp is defective.
X
Visit a qualified specialist workshop. 0002
Check Rear Left
Turn Signal or
Check Rear Right Turn Signal The rear left-hand or rear right-hand turn signal is defective.
X
Visit a qualified specialist workshop. Display messages
257On-board computer and displays Z