
Driving and operating193
Press V, the current setting is shown
in the Driver Information Centre.
Press V again to change the alert
sensitivity.
Alerting the driver
A green illuminated vehicle ahead
control indicator A illuminates in the
instrument cluster when the system has detected a vehicle in the driving
path.
When the distance to a preceding
moving vehicle gets too small or when
approaching another vehicle too
rapidly and a collision is imminent, the
collision alert symbol pops-up in the
Driver Information Centre.
Simultaneously, a warning chime
sounds. Depress the brake pedal, if it is required by the situation.
Deactivation
The system can be deactivated.
Press V repeatedly until Forward
Collision Alert Off appears in the
Driver Information Centre.
General information for both
variants of forward collision alert9 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 to
other metallic objects.

Driving and operating1959Warning
This system is not intended to
replace the driver responsibility for driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver must 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.
Below a speed of 11 mph the system
can apply full braking.
Forward looking brake assist
In addition to the brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. Therefore,
depressing the brake pedal less
strongly results in immediate hard
braking. This function helps the driver
brake quicker and harder before the
imminent collision.9 Warning
Active emergency braking is not
designed to apply hard
autonomous braking or to
automatically avoid a collision. It is designed to reduce the vehicle
speed before a collision. It may not
react for 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 wearingtheir 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 cases, the active emergency braking system may provide an
automatic braking in situations that
seem to be unnecessary, for instance
in parking garages, due to traffic signs in a curve or due to vehicles in
another lane. This is normal
operation, the vehicle does not need
service. Firmly apply the accelerator
pedal to override the automatic
braking.

224Vehicle careVehicle careGeneral Information...................225
Accessories and vehicle modifications .......................... 225
Vehicle storage ........................225
End-of-life vehicle recovery .....225
Vehicle checks ........................... 226
Performing work ......................226
Bonnet ..................................... 226
Engine oil ................................. 227
Automatic transmission fluid ....228
Engine coolant ......................... 229
Power steering fluid .................230
Washer fluid ............................ 230
Brakes ..................................... 231
Brake fluid ............................... 231
Vehicle battery ......................... 231
Diesel fuel system bleeding .....233
Wiper blade replacement ........233
Bulb replacement .......................234
Halogen headlights ..................235
Xenon headlights .....................237
Fog lights ................................. 239
Tail lights ................................. 240
Side turn signal lights ..............242
Number plate light ...................243Interior lights ............................ 244
Instrument panel illumination ...244
Electrical system ........................244
Fuses ....................................... 244
Engine compartment fuse box . 246
Instrument panel fuse box .......248
Load compartment fuse box ....249
Vehicle tools .............................. 251
Tools ........................................ 251
Wheels and tyres .......................252
Winter tyres ............................. 252
Tyre designations ....................252
Tyre pressure .......................... 252
Tyre pressure monitoring system .................................... 254
Tread depth ............................. 255
Changing tyre and wheel size . 256
Wheel covers ........................... 256
Tyre chains .............................. 257
Tyre repair kit .......................... 257
Wheel changing .......................260
Spare wheel ............................ 262
Jump starting ............................. 265
Towing ....................................... 266
Towing the vehicle ...................266
Towing another vehicle ...........268Appearance care .......................270
Exterior care ............................ 270
Interior care ............................. 272

Vehicle care231BrakesIn 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.
The brake fluid level must be betweenthe MIN and the MAX marks.
If fluid level is below MIN seek the
assistance of a workshop.
Brake and clutch fluid 3 274.
Vehicle battery
The vehicle battery is maintenance-
free provided that the driving profile
allows sufficient charging of the
battery. Short-distance-driving and
frequent engine starts can discharge
the battery. Avoid the use of
unnecessary electrical consumers.
Batteries do not belong in household
waste. They must be disposed of at
an appropriate recycling collection
point.
Laying up the vehicle for more than
four weeks can lead to vehicle battery
discharge. Disconnect the clamp from
the negative terminal of the vehicle
battery.
Ensure the ignition is switched off
before connecting or disconnecting
the vehicle battery.
The anti-theft alarm siren must be
deactivated as follows: Switch the ignition on then off, disconnect the
vehicle's battery within 15 seconds.
Battery discharge protection 3 139.

318IndexAAccessories and vehicle modifications .......................... 225
Active emergency braking ..........194
Active head restraints ...................46
Adaptive cruise control .......109, 183
Adaptive forward lighting ...109, 132
AdBlue ................................ 107, 164
Adjustable air vents ...................151
Airbag and belt tensioners .........104
Airbag deactivation ..............62, 104
Airbag label................................... 57 Airbag system .............................. 57
Air conditioning regular operation ................................ 153
Air conditioning system .............. 140
Air intake .................................... 152
Air vents...................................... 151
All-wheel drive ........................... 172
Antilock brake system ................ 172
Antilock brake system (ABS) .....106
Anti-theft alarm system ................34
Anti-theft locking system .............. 33 Appearance care ........................270
Armrest ................................... 52, 53
Armrest storage ........................... 70
Ashtrays ....................................... 92 Automatic anti-dazzle ..................39
Automatic climate control system .................................... 142Automatic dimming ......................38
Automatic light control ...............129
Automatic locking ........................27
Automatic transmission .............167
Automatic transmission fluid .......228
Autostop ............................. 109, 159
Auxiliary heater ........................... 151
B
Baselevel display ........................110
Battery discharge protection ......139
Battery voltage ........................... 120
Belts.............................................. 54
BlueInjection ............................... 164
Bonnet ....................................... 226
Brake and clutch fluid .................274
Brake and clutch system ...........105
Brake assist ............................... 175
Brake fluid .................................. 231
Brakes ............................... 172, 231
Breakdown.................................. 266
Bulb replacement ....................... 234
C Capacities .................................. 291
Cargo management system ........75
Car Pass ...................................... 21
Catalytic converter .....................164
Central locking system ................24
Centre console lighting ..............138
Changing tyre and wheel size ...256