
Lane Keeping Assist detects lane markings on
the road and can warn you before you leave
your lane unintentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and
200 km/h).
A warning may be given if a front wheel
passes over a lane marking. It will warn you by means of intermittent vibration in the steer-
ing wheel for up to 1.5 seconds.
Important safety notes G
WARNING
Lane Keeping Assist may not always clearly
recognize lane markings.
In this case, Lane Keeping Assist may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and stay in lane, in particular if
warned by Lane Keeping Assist. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane Keep-ing Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an accident nor 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 func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient 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 there are no, several or unclear lane mark-
ings for a lane, e.g. in areas with road con-
struction 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 road
Switching on Lane Keeping Assist X
Press button 0044.
Indicator lamp 0043lights up. The Lane Lane
Keeping Assist On
Keeping Assist On message appears in
the multifunction display. If all conditions
have been satisfied, there may be a warn-
ing.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected, the lines in the assistance graphics display 220
Driving systemsDriving and parking

Active Blind Spot Assist may not detect nar-
row vehicles, such as motorcycles or bicy-
cles, or may only detect them too late.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may
be indicated, especially if the vehicles are not
driving in the middle of their lane. This may be the case if there are vehicles at the inner edge
of your lane.
Due to the nature of the system:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
R warnings may be interrupted when driving
alongside particularly long vehicles, e.g.
trucks, for a prolonged time.
Warning display 0043
Warning display
Active Blind Spot Assist is not operational at
speeds below approximately 20 mph
(30 km/h). Vehicles in the monitoring range
are then not indicated.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp 0043on the corre-
sponding side lights up red. This warning is
always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (12 km/h).
If you select the reverse gear, Active Blind
Spot Assist is not operational. The brightness of the warning lamps is auto-
matically adapted to the brightness of the
surroundings.
When Active Blind Spot Assist is activated,
gray radar waves propagating backwards
appear next to the vehicle in the assistance
display in the multifunction display. Above a
speed of 20 mph (30 km/h), the color of the
radar waves in the assistance display
changes to green
0044. Active Blind Spot Assist
is then ready for use.
Visual and acoustic collision warning
If you switch on the turn signals to change
lanes and a vehicle is detected in the side
monitoring range, you receive a visual and
acoustic collision warning. You will then hear a double warning tone and red warning
lamp 0043flashes. If the turn signal remains on,
detected vehicles are indicated by the flash-
ing of red warning lamp 0043. There are no fur-
ther warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a
lateral collision in the monitoring range, a
course-correcting brake application is carried
out. This is meant to assist you in avoiding a
collision. G
WARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli- Driving systems
223Driving and parking
Z

If a lane-correcting brake application occurs,
display 0043appears in the multifunction dis-
play. The brake application also slightly
reduces vehicle speed.
This function is available in the range between
40 mph and 120 mph (60 km/h and
200 km/h).
A lane-correcting brake application can be
made after driving over a lane marking rec-
ognize as being solid or broken. Before this, a
warning must be given by means of intermit-
tent vibration in the steering wheel. In addi-
tion, a lane with lane markings on both sides must be recognized.
In the case of a broken lane marking being
detected, a lane-correcting brake application can only be made if a vehicle has been detec-
ted in the adjacent lane. Oncoming vehicles,
overtaking vehicles and vehicles in adjacent
lanes can be detected.
i A further lane-correcting brake applica-
tion can only occur after your vehicle has
returned to the original lane.
No lane-correcting brake application occurs
if:
R you clearly and actively steer, brake or
accelerate.
R you cut the corner on a sharp bend.
R you have switched on the turn signal.
R a driving safety system intervenes, e.g.
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist. R
you have adopted a sporty driving style with
high cornering speeds or high rates of
acceleration.
R ESP ®
is switched off.
R the transmission is not in position D.
R a loss of tire pressure or a defective tire has
been detected and displayed.
R an obstacle in the lane in which you are
driving has been detected.
Active Lane Keeping Assist may not detect
other road users or traffic situations. An inap- propriate brake application may be interrup-
ted at any time if you:
R steer slightly in the opposite direction
R switch on the turn signal
R clearly brake or accelerate
A lane-correcting brake application is inter-
rupted automatically if:
R a driving safety system intervenes, e.g.
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist.
R lane markings can no longer be recognized.
Switching on Active Lane Keeping Assist X
Press button 0044.
Indicator lamp 0043lights up. The Lane Lane
Keeping Assist On
Keeping Assist On message appears in
the multifunction display. If all conditions
have been satisfied, a warning or steering
intervention may be made.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected, the lines in the assistance graphics display 226
Driving systemsDriving and parking

It may be best to deactivate ESP
®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
For further information about ESP ®
, see
(Y page 71).
X Start the engine.
X Use 00E2 on the steering wheel to call up
the list of menus.
X Press the 0064or0063 button on the steer-
ing wheel to select the Settings
Settings menu.
X Confirm by pressing 0076on the steering
wheel.
X Use 0064 or0063 to select the DriveAs‐
DriveAs‐
sist
sist submenu.
X Press 0076to confirm.
X Press the 0064or0063 button to select
ESP
ESP.
X Press 0076to confirm.
The current selection is displayed.
X To activate/deactivate: press the0076
button again.
If the 00BB warning lamp in the instrument
cluster lights up when the vehicle is ready
to drive, ESP ®
is deactivated.
If the 00E5 and00BB warning lamps light up
continuously, ESP ®
is not available due to a
malfunction.
Observe the information on warning lamps
(Y page 288).
Observe the information on display messages
(Y page 251).
Activating/deactivating COLLISION PRE-
VENTION ASSIST PLUS
X Use 00E2 on the steering wheel to call up
the list of menus.
X Press the 0064or0063 button on the steer-
ing wheel to select the Settings
Settings menu.
X Confirm by pressing 0076on the steering
wheel. X
Use 0064 or0063 to select the DriveAs‐
DriveAs‐
sist sist submenu.
X Press 0076to confirm.
X Use 0063 or0064 to select Collision
Collision
Prevention
Prevention.
X Press 0076to confirm.
The current selection is displayed.
X To activate/deactivate: press the0076
button again.
When COLLISION PREVENTION ASSIST
PLUS is deactivated, the 00D4symbol
appears in the multifunction display in the
Assistance Graphic Assistance Graphic menu.
For further information about COLLISION
PREVENTION ASSIST PLUS, see (Y page 69).
Activating/deactivating PRE-SAFE ®
Brake
PRE‑SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
X Use 00E2 on the steering wheel to call up
the list of menus.
X Press the 0064or0063 button on the steer-
ing wheel to select the Settings
Settings menu.
X Confirm by pressing 0076on the steering
wheel.
X Use 0064 or0063 to select the Drive Drive
Assist
Assist submenu.
X Press 0076to confirm.
X Press the 0064or0063 button to select
PRE-SAFE Brake
PRE-SAFE Brake.
X Press 0076to confirm.
The current selection is displayed.
X To activate/deactivate: press the0076
button again.
When PRE-SAFE ®
Brake is deactivated, the
00D4 symbol appears in the Assistance Assistance
Graphic
Graphic menu in the multifunction dis-
play.
For more information on PRE ‑SAFE®
Brake,
see (Y page 74). Menus and submenus
245On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions 007A0025
00E5
Inoperative See Inoperative See
Operator's Manual Operator's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS,
PRE ‑SAFE ®
, HOLD function, Crosswind Assist, hill start assist,
STEER CONTROL, Active Lane Keeping Assist and Active Blind
Spot Assist are unavailable due to a malfunction.
BAS PLUS, PRE‑SAFE ®
Brake, PRE ‑SAFE®
PLUS and COLLISION
PREVENTION ASSIST PLUS may also have failed.
In addition, the 00E5,00BBand0025 warning lamps light up in the
instrument cluster and a warning tone sounds.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec- ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. 0049(USA
only)0024
(Canada
only)
Please Release Please Release
Parking Brake Parking Brake The red
0049(USA only)/0024 (Canada only) indicator lamp
flashes and a warning tone sounds. A condition for automatic
release of the electric parking brake is not fulfilled (Y page 176).
You are driving with the electric parking brake applied.
X Release the electric parking brake manually. The red
0049(USA only)/0024 (Canada only) indicator lamp
flashes and a warning tone sounds.
You are making an emergency stop using the electric parking
brake (Y page 176). 0049(USA
only)0024
(Canada
only)
Parking Brake See Parking Brake See
Operator's Manual Operator's Manual The yellow
0024warning lamp lights up.
The electric parking brake is malfunctioning.
To apply:
X Switch the ignition off.
X Press the electric parking brake handle for at least ten seconds.
X Shift the transmission to P.
X Consult a qualified specialist workshop. 254
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions The yellow
0024warning lamp and the red 0049(USA only)/ 0024
(Canada only) indicator lamp light up.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
or X Release the electric parking brake automatically (Y page 176).
If the electric parking brake still cannot be released: X Do not drive on.
X Consult a qualified specialist workshop. The red
0049(USA only)/0024 (Canada only) indicator lamp
flashes and the yellow 0024warning lamp lights up.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
To apply: X Switch off the ignition and turn it back on.
X Apply the electric parking brake manually.
If the red 0049(USA only)/ 0024(Canada only) indicator lamp
continues to flash:
X Do not drive on.
X Secure the vehicle against rolling away (Y page 382).
X Shift the transmission to P.
X Turn the front wheels towards the curb.
X Consult a qualified specialist workshop. Display
messages
255On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions The yellow
0024warning lamp lights up. The red 0049(USA
only)/ 0024(Canada only) indicator lamp flashes for about ten
seconds after the electric parking brake has been applied or
released. It then goes out or remains lit.
The electric parking brake is malfunctioning.
X Switch off the ignition and turn it back on.
X Apply the electric parking brake.
If it is not possible to engage the electric parking brake:
X Shift the transmission to P.
X Visit a qualified specialist workshop.
If it is not possible to release the electric parking brake manually: X Release the electric parking brake automatically (Y page 176).
If the electric parking brake still cannot be released:
X Consult a qualified specialist workshop. The yellow
0024warning lamp lights up. If you manually apply or
release the electric parking brake, the red 0049(USA only)/ 0024
(Canada only) indicator lamp flashes.
The electric parking brake is malfunctioning. It is not possible to
apply the electric parking brake manually.
X Shift the transmission to Pas the electric parking brake is not
being applied automatically.
X Visit a qualified specialist workshop.
If it is not possible to release the electric parking brake manually:
X Release the electric parking brake automatically (Y page 176).256
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 0049(USA
only)0024
(Canada
only)
Parking Parking Brake
BrakeInop‐
Inop‐
erative
erative The yellow
0024warning lamp lights up. The red 0049(USA
only)/ 0024(Canada only) indicator lamp flashes for about ten
seconds after the electric parking brake has been applied or
released. It then goes out or remains lit.
The electric parking brake is malfunctioning, e.g. because of over-
voltage or undervoltage.
X Remove the cause for the overvoltage or undervoltage, e.g. by
charging the battery or restarting the engine.
X Engage or release the electric parking brake.
If it remains impossible to apply or release the electric parking
brake:
X Switch off the ignition and turn it back on.
X Engage or release the electric parking brake.
If the electric parking brake still cannot be released: X Consult a qualified specialist workshop.
If the electric parking brake still cannot be applied: X Visit a qualified specialist workshop. The yellow
0024warning lamp lights up and the red 0049(USA
only)/ 0024(Canada only) indicator lamp flashes.
It is not possible to apply the electric parking brake manually.
X Shift the transmission to P.
X Visit a qualified specialist workshop. 0049(USA
only)0024
(Canada
only)
Turn On the Igni‐ Turn On the Igni‐
tion to Release tion to Release
the Parking Brake the Parking Brake The red
0049(USA only)/0024 (Canada only) indicator lamp lights
up.
You attempted to release the electric parking brake while the igni-
tion was switched off.
X Switch on the ignition. Display
messages
257On-board computer and displays Z