
Either no braking application, or a course-cor-
recting brake application adapted to the driving
situation occurs if: R
there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle. R
a vehicle approaches you too closely at the
side. R
you have adopted a sporty driving style with
high cornering speeds. R
you clearly brake or accelerate. R
a driving safety system intervenes, e.g. ESP ®
or PRE-SAFE ®
Brake.R
ESP ®
is switched off.R
a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist X
Make sure that Active Blind Spot Assist is
activated in the on-board computer
( Y
page 271). X
Turn the SmartKey to position 2 in the ignition
lock.
Warning lamps C in the exterior mirrors light
up red for approximately 1.5 second s. Gray
radar waves propagating backwards appear
next to the vehicle in the assistance display in
the multifunction display.
Active Lane Keeping Assist
General notes
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunction
camera C at 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 detects lane markings on the road and
can warn you before you leave your lane unin- tentionally. If you do not react to the warning, a
lane-correcting application of the brakes can
bring the vehicle back into the original lane.
This function is available in a speed range
between 40 mph and 120 mph (60 km/h and
200 km/h).
Important safety notes If you fail to adapt your driving style, Active Lane
Keeping Assist can neither reduce the risk of
accident nor override the laws of physics. Active
Lane Keeping Assist cannot take account of
road and weather conditions. It may not recog-
nize 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. Ter-
minate the intervention in a non-critical driv-
ing 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 vicin-
ity of the cameraDriving systems 237
Driving and parking Z

R
the radar sensors in the front or rear bumpers
or the radiator trim 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 cov-
ered 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 detec-
ted 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
If no vehicle is detected in the adjacent lane and
broken lane markings are detected, no lane-cor-
recting brake application is made.
Warning vibration in the steering wheel 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 steering wheel for
up to 1.5 second s.
In orde r that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, 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
Lane-correcting brake application
If you leave your lane, under certain circumstan-
ces the vehicle will brake briefly on one side.
This is meant to assist you in bringing the vehicle
back to the original lane.
G WARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original
lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns you or makes a lane-correcting brake appli-
cation.
G WARNING
Active Lane Keeping Assist does not detect
traffic conditions or road users. In very rare
cases, the system may make an inappropriate
brake application, e.g. after intentionally driv-
ing over a solid lane marking. There is a risk of
an accident.
An inappropriate brake application may be
interrupted at any time if you steer slightly in
the opposite direction. Always make sure that
there is sufficient distance on the side for
other traffic or obstacles.
If a lane-correcting brake application occurs,
display C appears in the multifunction display.
The brake application also slightly reduces vehi-
cle speed.
A lane-correcting brake application can be made
after driving over a lane marking recognized as
being solid or broken. Before this, a warning
must be given by means of intermittent vibration
in the steering wheel. In addition, a lane with
lane markings on both sides must be recog-
nized.
In the case of a broken lane marking being
detected, a lane-correcting brake application
can only be made if a vehicle has been detected
in the adjacent lane. The following vehicles can
have an influence on brake application: oncom-
ing traffic, vehicles that are overtaking and vehi-
cles that are driving parallel to your vehicle.
i A further lane-correcting brake application
can only occur after your vehicle has returned
to the original lane.238
Driving systems
Driving and parking

No lane-correcting brake application occurs if: R
you clearly and actively steer, brake or accel-
erate. 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 accel-
eration. 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 inappropriate
brake application may be interrupted 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 interrup-
ted 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 D .
Indicator lamp C lights up. The Lane Keep‐
ing Assist On message appears in the mul-
tifunction 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
( Y
page 268) are shown in green. Active Lane
Keeping Assist is ready for use. X
To switch off: press button D .
Indicator lamp C goes out. The Active Lane
Keeping Assist is deactivated. The Lane
Keeping Assist Off message appears in
the multifunction display.
Selecting Standard or Adaptive setting X
In the DriveAssist menu on the on-board
computer, select the Active Lane Keep‐
ing Assist function ( Y
page 271).X
Select Standard or Adaptive .
When Standard is selected, no warning vibra-
tion 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 ®
.
When Adaptive
is selected, no warning vibra-
tion 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 neces-
sary and in good time if you cross the lane mark-
ing, 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 bendDriving systems 239
Driving and parking Z

PLUG ‑ IN HYBRID operation
Points to remember
General notes Hybrid technology combines a fuel efficient
internal combustion engine with a powerful
electric motor. In HYBRID mode, the hybrid
drive system automatically selects the most effi-
cient operating mode for every driving situation.
Drive the vehicle in the usual manner.
To save fuel in HYBRID mode, the hybrid drive
system switches off the combustion engine as
often as possible during the journey when power
output requirements are low. When power out-
put requirements are low, the electric motor
powers the vehicle. The combustion engine is
automatically activated when power output
requirements are high. The engine is usually
switched off when the vehicle is stationary. Con-
sequently, there is usually no engine idling as
with combustion engine vehicles.
For pulling away and accelerating, the electric
motor supports the internal combustion engine
using the power stored in the high-voltage bat-
tery. In addition, the power is used for partially
electric driving, operation of the electric coolant
compressor and to support the 12 V on-board
electrical system. In this way the hybrid drive
system helps to reduce your vehicle's fuel con-
sumption.
Observe the driving tips on PLUG-IN HYBRID
operation ( Y
page 251).
Recuperative Brake System If you release the accelerator pedal when the
vehicle is in motion, overrun recuperation is ini-
tiated. The electric motor is operated as a gen-
erator when in overrun mode and when you
brake. Hybrid technology converts the kinetic
energy of the vehicle into electricity and stores
it in the high-voltage battery.
Observe the important safety notes for the
Recuperative Brake System ( Y
page 44). Important safety notes If the engine is switched off by the ECO start/
stop function and you open the driver's door: R
a message appears in the multifunction dis-
play and R
a warning tone sounds
Further information ( Y
page 297).
All of the vehicle's systems remain active, if: R
the vehicle is stationary R
the combustion engine is switched off and R
the READY indicator in the instrument cluster
lights up
If you remove your foot from the brake pedal
while in transmission position D or R, the vehicle
may pull away automatically.
Observe the notes on the READY display of the
ECO start/stop function ( Y
page 252).
Vehicles with an electric motor generate much
less driving noise than vehicles with internal
combustion engines. As a result, your vehicle
may not be heard by other road users in certain
situations.
Depending on the vehicle's equipment and
country-specific regulations, the vehicle can be
equipped with Acoustic Vehicle Indication.
Acoustic Vehicle Indication generates a certain
sound at a speed between 0 and 19 mph
(30 km/h). This helps other road users, partic-
ularly pedestrians and cyclists, to hear your
vehicle better. The sound can also be heard
inside the vehicle.
The volume depends on the engine speed. The
faster you accelerate, the louder the sound is. At
a speed of over 19 mph (30 km/h) the sound is
switched off. Above this speed, the natural
sounds from the vehicle are sufficient that it can
be heard in good time by other road users.240
PLUG ‑ IN HYBRID operation
Driving and parking