
protection measures (PRE-SAFE
®
) are
activated simultaneously.
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
BAS PLUS is deactivated and the brakes
function as usual, if:
R you release the brake pedal.
R there is no longer any danger of a rear-end
collision.
R no obstacle is detected in fron tofyour
vehicle.
If you have activated DSR (Y page 250), BAS
PLUS is likewise deactivated. G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations. BAS
PLUS cannot intervene in these cases. There
is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
In particular, the detection of obstacles can
be impaired if:
R there is dirt on the sensors or anything else
covering the sensors.
R snow or heavy rain
R interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering As
aresult, BAS PLUS may not intervene in all
critical situations. There is a risk of an
accident.
Always pay careful attention to the traffic
situation and be ready to brake.
Following damage to the fron tend of the
vehicle, have the configuratio nand operation
of the rada rsensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the fron tofthe vehicle. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
Adaptive Brake Assist and the distance
warning function, which are described in the
following.
Distance warning function Important safety notes
i
Observe the "Important safety notes"
section (Y page 66). G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
The distance warning function cannot always
clearly identify objects and complex traffic
situations. 68
Driving safety systemsSafety

Always pay careful attention to the traffic
situatio
nand be ready to brake. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic
situatio nand be ready to brake.
Adaptive Brake Assist provides braking
assistance in hazardous situations at speeds
greater than 20 mph (30 km/h) and uses
rada rsensor technology to assess the traffic
situation.
With the help of Adaptive Brake Assist, the
distance warning signal can detec tobstacles
that are in the path of your vehicle for an
extended period of time.
Should you approach an obstacle and
Adaptive Brake Assist has detected a risk of
collision, Adaptive Brake Assist calculates the
braking force necessary to avoid a rear-end
collision. Should you apply the brakes
vigorously, Adaptive Brake Assist will
automatically increase the braking force to a
level suitable for the traffic conditions.
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal.
R there is no longer any danger of a rear-end
collision.
R no obstacle is detected in fron tofyour
vehicle.
Adaptive Brake Assist is then deactivated. If Adaptive Brake Assist requires particularly
high brake pressure, preventive passenger
protection measures (PRE-SAFE
®
) are
deployed simultaneously.
Up to vehicle speeds of around 155 mph
(250 km/h), adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles.
If Adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section (Y page 66).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tires and
the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one 70
Driving safety systemsSafety

0002
Battery compartment cover
0003 Mechanical key
X Press mechanical key 0003into the opening
in the SmartKey in the direction of the
arrow until battery compartment cover 0002
opens. Do not hold battery compartment
cover 0002closed while doing so.
X Remove battery compartment cover 0002.0021
Battery
X Repeatedly tap the SmartKey against your
palm until battery 0021falls out.
X Inser tthe new battery with the positive
terminal facing upwards. Use a lint-free
cloth to do so.
X Make sure that the surface of the battery is
free from lint, grease and all other forms of
contamination. X
Insert the front tabs of battery
compartment cover 0002into the housing
first and then press to close it.
X Insert mechanical key 0003into the
SmartKey.
X Check the function of all SmartKey buttons
on the vehicle. 82
SmartKeyOpening and closing

i
For more information on driving with
snow chains, see (Y page 403).
Drive particularly carefully on slippery road
surfaces. Avoid sudde nacceleration, steering
and braking maneuvers. Do not use the cruise
control or DISTRONIC PLUS.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are
displayed afte rashort delay.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges. You
should pay special attention to road
conditions when temperatures are around
freezing point. Off-road driving
Important safety notes G
WARNING
If you drive on a steep incline at an angle or
turn when driving on an incline, the vehicle
could slip sideways, tip and rollover. There is
a risk of an accident.
Always drive on a steep incline in the line of
fall (straight up or down) and do not turn the
vehicle. G
WARNING
If the vehicle level is high, the vehicle center
of gravity is raised. This could cause the
vehicle to tip over more easily on uphill or
downhill gradients. There is arisk of an
accident.
Selec tthe lowest possible vehicle level.
When driving off-road, sand, mud and water,
possibly mixed with oil, for example, could get
into the brakes. This could result in a reduced
braking effect or in total brake failure and also
in increased wear and tear. The braking
characteristics change depending on the material ingressing the brakes. Cleant
he
brakes after driving off-road. If you detect a
reduced braking effect or grinding noises,
have the brake system checked in a qualified
specialist workshop as soon as possible.
Adapt your driving style to the different
braking characteristics.
Driving off-road increases the likelihood of
damage to the vehicle, which, in turn, can lead
to failure of the mechanical assembly or
systems. Adapt your driving style to suit the
terrain conditions. Drive carefully. Have
damage to the vehicle rectified immediately
at a qualified specialist workshop.
Do not switch to transmission position N
when driving off-road. You could lose control
of the vehicle if you attempt to brake using
the service brake. If the gradient is too steep,
drive backwards in reverse gear.
General notes Read this section carefully before driving your
vehicle off-road. Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain.
The following driving systems are specially
adapted to off-road driving:
R
Off-road ABS (Y page 67)
R AIRMATIC package (vehicle level)
(Y page 212)
R DSR (Downhill Speed Regulation)
(Y page 250)
Observe the following notes:
R Stop the vehicle before starting to drive
along an off-road route.
R For vehicles with the AIRMATIC
package: select a vehicle level that is
suitable for the off-road terrain. To avoid
damaging the vehicle, make sure there is
always sufficient ground clearance.
R Check that items of luggage and loads are
stowed safely and are well secured
(Y page 341). Driving tips
191Driving and parking Z

R
When driving down an incline, make use of
the engine's braking effect. Observe the
engine speed; do not overrev the engine.
R Check the brakes after prolonged off-road
driving.
i Hill start assist will aid you when pulling
away on a hill.
For more information, see "Hill start assist"
(Y page 166).
Do not switch to transmission position N
when driving off-road. If you try to brake the
vehicle using the service brake, you could
lose control of the vehicle. If the gradient is
too steep for your vehicle, drive back down in
reverse gear.
Maximum gradient-climbing capability On good road surfaces the maximum
gradient-climbing capability of your vehicle is
100%, which corresponds to an approach/
departure angle of 45°. Note that the
vehicle's gradient-climbing capability
depends on the off-road conditions.
Accelerate carefully and make sure that the
wheels do not spin when driving on steep
terrain.
i If the load on the front axle is reduced
when pulling away on a steep uphill slope,
the fron twheels have a tendency to spin.
4ETS recognizes this and brakes the
wheels accordingly. The rear wheel torque
is increased, making it easier to drive off.
Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator
immediately before reaching the brow of the
hill. Use the vehicle's own impetus to drive
over the top of the hill.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R the vehicle from traveling too quickly down
the other side Driving downhill R
Drive slowly.
R Do not drive at an angle down steep
inclines. Steer into the line of fall and drive
with the front wheels aligned straight.
Otherwise, the vehicle could slip sideways,
tip and rollover.
R Before tackling steep downhill gradients,
select shift range 1.
R Activate DSR. If this is not sufficient, brake
gently. When doing so, make sure that the
vehicle is facing in the direction of the line
of fall.
R Check that the brakes are working normally
after a long downhill stretch.
i The special off-road ABS setting enables
a precise, brief and repeated locking of the
front wheels. This causes them to dig into
loose earth. Be aware that the front wheels
easily skid across the ground surface if
completely braked and therefore lose their
ability to steer. Driving systems
Cruise control
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an
accident nor override the laws of physics.
Cruise control cannot take into account the
road, traffic and weather conditions. Cruise
control 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.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or
accelerating could cause the drive wheels Driving systems
195Driving and parking Z

maneuvering, parking or pulling out of a
parking space, make sure that there are no
persons, animals or objects in the area in
which you are maneuvering.
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is activated automatically when
you:
R switch on the ignition
R shift the transmission to position D,Ror N
R release the electric parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper. 0002
Sensors in the front bumper, left-hand
side (example) Range of the sensors General notes
PARKTRONIC does not take objects into
consideration that are:
R
below the detection range, e.g. people,
animals or objects
R above the detection range, e.g.
overhanging loads, truck overhangs or
loading ramps. Side view
Top view
The sensors must be free from dirt, ice or
slush. They can otherwise not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y
page 375).
Front sensors Center Approx. 40i
n(approx.
100cm) Corners Approx. 24in (approx.
60cm)218
Driving systemsDriving and parking

symbol
0002is 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
If 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 earlieri f:
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 soli dlane markings.
The warning vibratio noccurs later if:
R the road has narrow lanes.
R you cut the corner on a bend. Active Driving Assistance package
General notes The Active Driving Assistance package
consists of DISTRONIC PLUS (Y
page 198),
Active Blind Spot Assist (Y page 241) and
Active Lane Keeping Assist (Y page 245).
Active Blind Spo tAssist General notes
Active Blind Spot Assist uses a radar sensor
system to monitor the side areas of your
vehicle which are behind the driver.
Awarning
display in the exterior mirrors draws your
attentio nto vehicles detected in the
monitored area. If you then switch on the
corresponding turn signal to change lane, you
will also receive an optical and audible
warning. If a risk of lateral collision is
detected, corrective braking may help you
avoid a collision. To support the course-
correcting brake application, Active Blind
Spot Assist uses the forward-facing radar
sensor system. The free space in the direction
of travel is then evaluated.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/h).
For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be:
R activated (Y page 281)
R operational
Important safety notes
Active Blind Spot Assist is only an aid. It may
fail to detect some vehicles and is no
substitute for attentive driving. G
WARNING
Active Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R vehicles approaching and driving by with a
speed difference of more than
approximately 6.8 mph (11 km/h) Driving systems
241Driving and parking
Z

R
ESP ®
is switched off.
R the transmission is not in position D.
R on vehicles with a trailer tow hitch, the
electrical connectio nto the trailer has been
correctly established.
R the off-road program is activated (vehicles
without the ON&OFFROAD package).
R off-road program 1 or 2 is activated
(vehicles with the ON&OFFROAD package).
R the LOW RANGE off-road gear is activated
(vehicles with the ON&OFFROAD package).
R a loss of tire pressure or a defective tire has
been detected and displayed.
Active Lane Keeping Assist does not detect
traffic situations or road users. 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
Al ane-correcting brake applicatio nis
interrupted 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
Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard or
Adaptive (Y
page 277).
Symbol 0002appears in the multifunction
display.
If Standard is selected, no warning
vibration occurs if: R
you switch on the tur nsignals .Inthis
event, the warnings are suppressed for a
certain period of time.
R a driving safety system intervenes, such
as ABS, BAS or ESP ®
.
If 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.
Towing atrailer
When you attach a trailer, make sure you have
correctly established the electrical
connection. This can be accomplished by
checking the trailer lighting. On-road programs (vehicles with the
ON&OFFROAD package)
General notes The on-road programs assist you during on-
road driving and the off-road programs when
driving off-road (Y
page 252).
The following progra mmessages remain in
the multifunction display until the
corresponding vehicle level has been set. Up
to off-road level 2, you can hide the program
messages using the 0007or000B button on
the multifunction steering wheel. Driving systems
247Driving and parking Z