Page 188 of 297

186Driving and operating
Deactivation
The system can be deactivated.
Press button V repeatedly until the
following message appears in the
Driver Information Centre.
General information for both
variants of forward collision alert
9 Warning
Forward collision alert is just a
warning system and does not
apply the brakes. When
approaching a vehicle ahead too
rapidly, it may not provide you
enough time to avoid a collision.
The driver accepts full
responsibility for the appropriate
following distance based on traffic, weather and visibility conditions.
The complete attention of the
driver is always required while
driving. The driver must always be
ready to take action and apply the
brakes.
System limitations
The system is designed to warn only for vehicles, but may react also onother metallic objects.
In the following cases, forward
collision alert may not detect a vehicle ahead or sensor performance is
limited:
■ on winding roads,
■ when weather limits visibility, such as fog, rain, or snow,
■ when the sensor is blocked by snow, ice, slush, mud, dirt, or
windscreen damage.
Following distance
indication
The following distance indication
displays the distance to a preceding
moving vehicle. The system uses,
depending on the vehicle equipment,
either the radar behind the radiator
grille or the front camera in the
windscreen to detect the distance of
a vehicle directly ahead in your lane.
It is active at speeds above 25 mph.
When a preceding vehicle is detected
ahead, the distance is indicated in
seconds, displayed on a page in the
Driver Information Centre 3 114.
Press the MENU button on the turn
signal lever to select Vehicle
Information Menu X and turn the
adjuster wheel to choose following
distance indication page.
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Driving and operating187
The minimum indicated distance is
0.5 s.
If there is no vehicle ahead or the vehicle ahead is out of range, two
dashes will be displayed: -.- s.
Active Emergency Braking
Active emergency braking can help to reduce the damage from crashes with vehicles and obstacles directly
ahead, when a collision can no longer be avoided either by manual braking
or by steering. Before the active
emergency braking applies, the driver
is warned by the forward collision
alert 3 183.
The feature uses various inputs (e.g.
radar sensor, brake pressure, vehicle speed) to calculate the probability of
a frontal collision.
Active emergency braking operates automatically above walking speed,
provided that Auto collision
preparation setting is not deactivated
in the vehicle personalisation menu
3 126.
The system includes: ■ Brake preparation system
■ Emergency automatic braking
■ Forward looking brake assist9 Warning
This system is not intended to
replace the driver responsibility of driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver
shall continue to apply the brake
pedal as the driving situation
dictates.
Brake preparation system
When approaching a vehicle ahead
so quickly that a collision is likely, the brake preparation system slightly
pressurises the brakes. This reduces
the response time, when a manual or automatic braking is requested.
The brake system is prepared so that braking can occur more rapidly.
Emergency automatic braking After the brake preparation and just
before the imminent collision, this
function automatically applies limited
braking to reduce the impact speed of
the collision.
Forward looking brake assist
In addition to brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. In this way,
depressing the brake pedal slightly
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188Driving and operating
results immediately in a strong
braking. This function helps the driver brake quicker and stronger before theimminent collision.9 Warning
Active emergency braking is not
designed to apply strong
autonomous braking or to avoid automatically a collision. It is
designed to reduce the vehicle
speed before collision. It may not
react on stopped vehicles,
pedestrians or animals. After a
sudden lane change, the system
needs a certain time to detect the
next preceding vehicle.
The complete attention of the
driver is always required while
driving. The driver shall always be ready to take action and apply the brakes and steer to avoid
collisions. The system is designed
to work with all occupants wearing their seat belts.
System limitations
The active emergency braking has
limited or no function during rain,
snow or heavy dirt, as the radar
sensor can be covered by a water
film, dust, ice or snow. In case of
sensor blockage, clean the sensor
cover.
In some seldom cases the active
emergency braking system may
provide a short automatic braking in
situations that seem to be
unnecessary, for instance due to
traffic signs in a curve or due to
vehicles in another lane. This is
acceptable operation, the vehicle
does not need service. Firmly apply
the accelerator pedal to override the
automatic braking.
Settings Settings can be changed in the Auto
collision preparation menu in the
vehicle personalisation, 3 126.
Fault
In the event of a system service
requirement, a message is displayed
in the Driver Information Centre.
If the system does not work as it
should, vehicle messages are
displayed in the Driver Information
Centre.
Vehicle messages 3 120.
Page 224 of 297
222Vehicle care
Power steering fluid level normally
does not have to be checked. If an
unusual noise sounds during steering or the power steering reacts
unusually, seek the assistance of a
workshop.
Washer fluid
Fill with clean water mixed with a
suitable quantity of windscreen
washer fluid which contains
antifreeze.
Caution
Only washer fluid with a sufficient
antifreeze concentration provides
protection at low temperatures or
a sudden drop in temperature.
Brakes
In the event of minimum thickness ofthe brake lining, a squealing noise
sounds during braking.
Continued driving is possible but
have the brake lining replaced as
soon as possible.
Once new brake linings are installed,
do not brake unnecessarily hard for
the first few journeys.
Brake fluid9 Warning
Brake fluid is poisonous and
corrosive. Avoid contact with eyes, skin, fabrics and painted surfaces.
Page 292 of 297

290IndexAAccessories and vehicle modifications .......................... 217
Active Emergency Braking .........187
Active head restraints ...................36
Adaptive cruise control .......113, 176
Adaptive forward lighting ..........
................................ 113, 135, 228
AdBlue ........................ 111, 160, 265
Adjustable air vents ...................150
Airbag and belt tensioners .........108
Airbag deactivation ..............55, 108
Airbag system .............................. 53
Air conditioning regular operation ................................ 152
Air conditioning system .............. 145
Air intake .................................... 152
Air vents...................................... 150
Antilock brake system ................ 167
Antilock brake system (ABS) .....110
Anti-theft alarm system ................25
Anti-theft locking system .............. 25
Appearance care ........................260
Armrest ......................................... 41
Armrest storage ........................... 65
Ashtrays ..................................... 100
Automatic anti-dazzle ..................29
Automatic light control ...............133
Automatic locking ........................23Automatic transmission .............163
Auxiliary heater ........................... 150
B
Battery discharge protection ......143
Battery voltage ........................... 123
Bicycle rack .................................. 67
BlueInjection ............................... 160
Bonnet ....................................... 219
Brake and clutch fluid .................265
Brake and clutch system ...........109
Brake assist ............................... 169
Brake fluid .................................. 222
Brakes ............................... 167, 222
Breakdown.................................. 258
Bulb replacement ....................... 226
C Capacities .................................. 281
Cargo management system ........85
Car Pass ...................................... 19
Catalytic converter .....................160
Central locking system ................21
Centre console lighting ..............142
Centre console storage ...............66
Changing tyre and wheel size ...247
Charging system ........................ 108
Child locks ................................... 23
Child restraint installation locations ................................... 58