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Driving and operating219DeactivationThe system is deactivated by
pressing a; the LED in the button
extinguishes.
The system is deactivated
automatically when a trailer is
detected.
Fault
The system performance may be affected by:
● Windscreen not clean or affected
by foreign items, e.g. stickers
● Close vehicles ahead
● Banked roads
● Winding or hilly roads
● Road edges
● Roads with poor lane markings
● Sudden lighting changes
● Adverse environmental conditions e.g. heavy rain or
snow
● Vehicle modifications, e.g. tyres.Switch off the system if the system is
disturbed by tar marks, shadows,
road cracks, temporary or
construction lane markings, or other
road imperfections.9 Warning
Always keep your attention on the
road and maintain proper vehicle
position within the lane, otherwise
vehicle damage, injury or death
could occur.
Lane keep assist does not
continuously steer the vehicle.
The system may not keep the
vehicle in the lane or give an alert,
even if a lane marking is detected.
The steering of the lane keep
assist may not be sufficient to
avoid a lane departure.
The system may not detect hands-
off driving due to external
influences (road condition and
surface, weather etc). The driver
has full responsibility to control the
vehicle and is always required to keep the hands on the steeringwheel while driving.
Using the system while towing a
trailer or on slippery roads could
cause loss of control of the vehicle
and a crash. Switch the system off.
Page 227 of 317

Driving and operating225Trailer 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.
During trailer towing do not exceed a
speed of 50 mph. A maximum speed
of 60 mph is only appropriate if an oscillation damper is used and the
permissible gross trailer weight does
not exceed the vehicle's curb weight.
For trailers with low driving stability
and caravan trailers, the use of an
oscillation damper is strongly
recommended.
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 3 296.Trailer towing
Trailer loadsThe 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 12%.
The permissible trailer load applies
up to the specified incline and at 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 altitude. The gross train weight does not have to be
reduced when driving on roads with
slight inclines (less than 8%, e.g.
motorways).
Page 228 of 317

226Driving and operatingThe permissible gross train weight
must not be exceeded. This weight is
specified on the identification plate
3 283.
Vertical coupling load The vertical coupling load is the load
exerted by the trailer on the coupling
ball. It can be varied by changing the
weight distribution when loading the
trailer.
The maximum permissible vertical
coupling load (75 kg) is specified on
the towing equipment identification
plate and in the vehicle documents.
Always aim for the maximum load,
especially in the case of heavy
trailers. The vertical coupling load
should never fall below 25 kg.
Rear axle load When the trailer is coupled and the
towing vehicle fully loaded, the
permissible rear axle load (see
identification plate or vehicle
documents) may be exceeded by 40 kg. If the permissible rear axle load
is exceeded, a maximum speed of
60 mph applies.Towing equipmentCaution
When operating without a trailer,
remove the coupling ball bar.
Stowage of coupling ball bar
The bag with the coupling ball bar is
stowed on the rear floor cover in the
load compartment.
Place the strap through the rear right
lashing eye, wrap around twice and
tighten the strap to secure the bag.
Illustration shows 5-door hatchback.
Illustration shows Sports Tourer.
Fitting the coupling ball bar
On Sports Tourer remove cover from
rear bumper by pushing.
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228Driving and operatingInsert the tensioned coupling ball bar
in the opening and push firmly
upwards until it audibly engages.
The rotary handle snaps back into its
original position resting against the
coupling ball bar without a gap.9 Warning
Do not touch rotary handle during
insertion.
Lock the coupling ball bar by turning
the key to position e. Remove the key
and close the protective flap.
Eye for break-away stopping cable
Illustration shows 5-door hatchback.
Illustration shows Sports Tourer.
Attach 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
Page 231 of 317
Driving and operating229Open 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 connecting socket.
On Sports Tourer insert cover into
rear bumper as shown in the
illustration.
Stow the coupling ball bar in the bag
and secure by fixing the strap through the rear right lashing eye. Wrap
around twice and tighten the strap to
secure the bag.
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 3 182.
Page 253 of 317

Vehicle care251No.Circuit33Anti theft warning horn34Horn35Power outlet load compartment36Right high beam (Halogen)/
Right low beam (LED)37Left high beam (Halogen)38LED headlight/Automatic head‐
light range adjustment39Front fog light40Central Gateway Module41Water in fuel sensor/Water
pump42Manual headlight range adjust‐
ment43Fuel pump44Rear view camera/Inside rear
view mirror/Trailer module45LED headlight left/Automatic
headlight range adjustment leftNo.Circuit46Instrument cluster47Steering column lock48Rear wiper49Outside rearview mirror50LED headlight right/Automatic
headlight range adjustment
right51Left low beam (LED)52Engine control module/Trans‐
mission control module53–54Windscreen wiper55Diesel exhaust system56–57–
After having changed defective fuses,
close the fuse box cover and press
until it engages.
If the fuse box cover is not closed
correctly, malfunction may occur.
Instrument panel fuse box
The fuse box is located behind a
cover.
Pull the cover and remove.
Vehicles with power connector:
If the fuse cover has a power
connector, it must be removed by
using an adapter and a screwdriver.
The adapter is stowed in the glovebox 3 70 . The screwdriver is stowed in the
load compartment 3 255.
Page 256 of 317
254Vehicle care
Remove the cover.
Disengage the fuse box cover and
remove it.
No.Circuit1–2–3Trailer module4Power seat passenger side5–6Distance warning module7–8–9Rear seat heating (on vehicles
without alarm horn)10Service11–12Front seat heating (on vehicles
with alarm horn)13Rear seat heating (on vehicles
with alarm horn)14Ignition15Seat ventilation
Page 257 of 317
Vehicle care255No.Circuit16Trailer outlet17Trailer outlet18–19–20–21Electrical rear seat folding (only
Caravan)22–
After having changed defective fuses,
close the fuse box cover and press
until it engages.
Additional fuses are located near the
vehicle battery.
No.Circuit1Fuel pump2Engine control module3Power supplyVehicle tools
Tools
5-door hatchback with spare
wheel
Open the floor cover of the load
compartment 3 80.
The jack, the towing eye, a strap for
securing a damaged wheel and the
tools are located in the tool box below the spare wheel. Spare wheel
3 269.