
Driving and operating169Active emergency braking
Active emergency braking can help to reduce the damage and injury 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 3 166.
The feature uses various inputs (e.g.
camera sensor, brake pressure,
vehicle speed) to calculate the
probability of a frontal collision.
Active emergency braking operates
above walking speed up to 53 mph. A precondition is that the system is not
deactivated by toggling the gap
switch V to Off setting, 3 166.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist9 Warning
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.
The system operates up to a speed of 50 mph.
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 or prohibit a crash.
The system operates up to a speed of 37 mph.
Below a speed of 25 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.
The system operates up to a speed of 53 mph.

170Driving and operating9Warning
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 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 camera
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.
Deactivation
Active emergency braking can be
deactivated by repeatedly pressing
the gap switch V to Off setting,
3 166. If deactivated a message is
displayed in the Driver Information
Centre.
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 do, vehicle messages are
displayed in the Driver Information
Centre.
Vehicle messages 3 104.
Parking assist Rear parking assist9 Warning
It is the driver who bears full
responsibility for the parking
manoeuvre.
Always check the surrounding
area while reversing and using the rear parking assist system.

176Driving and operating
When a slot is detected, a visual
feedback on the Colour-Info-Display
and an acoustic signal is given.
If the driver does not stop the vehicle after a parking slot is proposed, the
system starts to search for another
suitable parking slot.
Park guiding mode
The parking slot suggestion of the system is accepted when the vehicle
is stopped by the driver within
10 metres for parallel parking slots or
six metres for perpendicular parking
slots after the Stop message is given.
The system calculates the optimal
path into the parking slot.A brief vibration in the steering wheel
after engaging reverse gear indicates
that the steering is controlled by the
system. Then the vehicle is steered
into the slot automatically by giving
the driver detailed instructions for
braking, accelerating and gear
shifting. The driver must keep hands
away from the steering wheel.
Always pay attention to the sound of
the front-rear parking assist.
Continuous sound indicates that the
distance to an obstacle is less than
approx. 30 cm.
If, for any reason, the driver must take over control of the steering, hold the
steering wheel only at the outer edge. Automatic steering is cancelled in thisevent.Display indication
The instructions on the display show:
● General hints and warning messages.
● A hint when driving faster than 18 mph during parking slot
searching mode.
● The demand to stop the vehicle, when a parking slot is detected.●The direction of driving during the
parking manoeuvre.
● The demand to shift into reverse or first gear.
● The demand to accelerate or brake.
● For some of the instructions a progress bar is shown in the
Driver Information Centre.
● The successful completion of the
parking manoeuvre indicated by
a pop-up symbol and a chime.
● The cancelling of a parking manoeuvre.
Display priorities
Advanced parking assist indication in the Driver Information Centre can be
inhibited by vehicle messages with a
higher priority. After approving the
message by pressing SET/CLR on
the turn signal lever or 9 on the
steering wheel, advanced parking assist instructions appear again and
the parking manoeuvre can be
continued.

190Driving and operatingTrailer hitch
General information
Only use towing equipment that has
been approved for your vehicle.
Entrust retrofitting of towing
equipment to a workshop. It may be
necessary to make changes that
affect the cooling system, heat
shields or other equipment.
The bulb outage detection function for trailer brake light cannot detect a
partial bulb outage, e.g. in case of four
times five watt bulbs, the function only detects lamp outage when only a
single five Watt lamp remains or none
remain.
Fitting of towing equipment could
cover the opening of the towing eye.
If this is the case use the coupling ball bar for towing. Always keep the
coupling ball bar in the vehicle when
not in use.Driving characteristics and
towing tips
Before attaching a trailer, lubricatethe coupling ball. However, do not do
so if a stabiliser, which acts on the
coupling ball, is being used to reduce snaking movements.
For trailers with low driving stability
and caravan trailers with a permitted
gross vehicle weight of more than
1300 kg the use of a stabiliser is
strongly recommended when driving
above 50 mph.
If the trailer starts snaking, drive more
slowly, do not attempt to correct the
steering and brake sharply if
necessary.
When driving downhill, drive in the
same gear as if driving uphill and
drive at a similar speed.
Adjust tyre pressure to the value
specified for full load 3 253.Trailer towing
Trailer loads
The permissible trailer loads are
vehicle and engine-dependent
maximum values which must not be
exceeded. The actual trailer load is
the difference between the actual
gross weight of the trailer and the
actual coupling socket load with the
trailer coupled.
The permissible trailer loads are
specified in the vehicle documents. In general, they are valid for gradients
up to max. 12%.
The permitted trailer load applies up to the specified incline and up to an
altitude of 1000 metres above sea
level. Since engine power decreases
as altitude increases due to the air becoming thinner, therefore reducing
climbing ability, the permissible gross
train weight also decreases by 10%
for every 1000 metres of additional
altitude. The gross train weight does
not have to be reduced when driving
on roads with slight inclines (less than 8%, e.g. motorways).

Driving and operating193Attach breakaway stopping cable to
eye.
Check that the coupling ball bar is
correctly installed
● Green marking on rotary knob must point towards green
marking on coupling ball bar.
● There must be no gap between the rotary handle and the
coupling ball bar.
● The coupling ball bar must be firmly engaged in the opening.
● The coupling ball bar must be locked and the key removed.9Warning
Towing a trailer is permitted only
when a coupling ball bar is fitted correctly. If the coupling ball bardoes not engage correctly, seekthe assistance of a workshop.
Dismounting the coupling ball bar
Open the protective flap and turn the
key to position c to unlock the
coupling ball bar.
Pull out rotary handle and turn
clockwise as far as it will go. Pull out coupling ball bar downwards.
Insert sealing plug in opening. Fold away socket.
Trailer stability assist
If the system detects snaking
movements, engine power is reduced
and the vehicle/trailer combination is
selectively braked until the snaking ceases. While system is working keep steering wheel as still as possible.
Trailer stability assist is a function of
the Electronic Stability Control 3 160.

194Vehicle careVehicle careGeneral Information...................194
Accessories and vehicle modifications .......................... 194
Vehicle storage ........................195
End-of-life vehicle recovery .....195
Vehicle checks ........................... 196
Performing work ......................196
Bonnet ..................................... 196
Engine oil ................................. 197
Engine coolant ......................... 198
Washer fluid ............................ 199
Brakes ..................................... 199
Brake fluid ............................... 199
Vehicle battery ......................... 200
Diesel fuel system bleeding .....201
Wiper blade replacement ........202
Bulb replacement .......................202
Halogen headlights ..................202
Fog lights ................................. 204
Tail lights ................................. 205
Side turn signal lights ..............208
Number plate light ...................209
Interior lights ............................ 210
Instrument panel illumination ...210Electrical system ........................210
Fuses ....................................... 210
Engine compartment fuse box . 211
Instrument panel fuse box .......213
Load compartment fuse box ....215
Vehicle tools .............................. 217
Tools ........................................ 217
Wheels and tyres .......................217
Winter tyres ............................. 217
Tyre designations ....................218
Tyre pressure .......................... 218
Tyre pressure monitoring system .................................... 219
Tread depth ............................. 223
Changing tyre and wheel size . 224 Wheel covers ........................... 224
Tyre chains .............................. 224
Tyre repair kit .......................... 224
Wheel changing .......................227
Spare wheel ............................ 230
Jump starting ............................. 232
Towing ....................................... 234
Towing the vehicle ...................234
Towing another vehicle ...........235
Appearance care .......................236
Exterior care ............................ 236
Interior care ............................. 237General Information
Accessories and vehiclemodifications
We recommend the use of genuine
parts and accessories and factory
approved parts specific for your
vehicle type. We cannot assess or guarantee reliability of other products
- even if they have a regulatory or
otherwise granted approval.
Do not make any modifications to the
electrical system, e.g. changes of
electronic control units (chip tuning).Caution
When transporting the vehicle on
a train or on a recovery vehicle, the
mud flaps might be damaged.

Vehicle care195Vehicle storageStorage for a long period of time
If the vehicle is to be stored for several months:
● Wash and wax the vehicle.
● Have the wax in the engine compartment and underbody
checked.
● Clean and preserve the rubber seals.
● Fill up fuel tank completely.
● Change the engine oil.
● Drain the washer fluid reservoir.
● Check the coolant antifreeze and
corrosion protection.
● Adjust tyre pressure to the value specified for full load.
● Park the vehicle in a dry, well ventilated place. Engage first or
reverse gear or set selector lever
to P. Prevent the vehicle from
rolling.
● Do not apply the parking brake.● Open the bonnet, close all doors and lock the vehicle.
● Disconnect the clamp from the negative terminal of the vehicle
battery. Beware that all systems
are not functional, e.g. anti-theft
alarm system.
Putting back into operation
When the vehicle is to be put back into
operation:
● Connect the clamp to the negative terminal of the vehicle
battery. Activate the electronics
of the power windows.
● Check tyre pressure.
● Fill up the washer fluid reservoir.
● Check the engine oil level.
● Check the coolant level.
● Fit the number plate if necessary.End-of-life vehicle recovery
Information on end-of-life vehicle
recovery centres and the recycling of
end-of-life vehicles is available on our website, where legally required. Only
entrust this work to an authorised
recycling centre.

Vehicle care199Washer fluid
Fill with clean water mixed with a
suitable quantity of approved
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 of
the 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 MAX marks.
If fluid level is below MIN seek the
assistance of a workshop.
Brake and clutch fluid 3 240.