Driving and operating167Caution
It is not advisable to drive with thehand resting on the selector lever.
Brakes
The brake system comprises two independent brake circuits.
If a brake circuit fails, the vehicle can
still be braked using the other brake
circuit. However, braking effect is
achieved only when the brake pedal
is depressed firmly. Considerably
more force is needed for this. The
braking distance is extended. Seek the assistance of a workshop before
continuing your journey.
When the engine is not running, the
support of the brake servo unit
disappears once the brake pedal has been depressed once or twice.
Braking effect is not reduced, but
braking requires significantly greater
force. It is especially important to bear
this in mind when being towed.
Control indicator R 3 109.
Antilock brake system
Antilock brake system (ABS)
prevents the wheels from locking.ABS starts to regulate brake pressure as soon as a wheel shows a tendency to lock. The vehicle remains
steerable, even during hard braking.
ABS control is made apparent
through a pulse in the brake pedal
and the noise of the regulation
process.
For optimum braking, keep the brake
pedal fully depressed throughout the
braking process, despite the fact that
the pedal is pulsating. Do not reduce
the pressure on the pedal.
After starting off the system performs
a self-test which may be audible.
Control indicator u 3 110.
Adaptive brake light During full braking, all three brake
lights flash for the duration of ABS
control.
168Driving and operating
Fault9Warning
If there is a fault in the ABS, the
wheels may be liable to lock due
to braking that is heavier than
normal. The advantages of ABS are no longer available. During
hard braking, the vehicle can no longer be steered and may
swerve.
Have the cause of the fault remedied
by a workshop.
Parking brake
Manual parking brake
Always apply parking brake firmly
without operating the release button,
and apply as firmly as possible on a
downhill or uphill slope.
To release the parking brake, pull the lever up slightly, press the release
button and fully lower the lever.
To reduce the operating forces of the
parking brake, depress the foot brake
at the same time.
Control indicator R 3 109.
Electric parking brake
Applying when vehicle is stationary
Pull switch m for approx.
one second; the electric parking
brake is applied automatically with an adequate force. For maximum force,
e.g. parking with trailer or on inclines:
pull switch m twice.
The electric parking brake is applied
when control indicator m illuminates
3 109.
The electric parking brake can always
be activated, even if the ignition is off.
180Driving and operating
■ Electronic Stability Control isoperating,
■ there is no traffic and nothing detected on the road sides for
several minutes. In this case there are no radar echoes and the sensor may report that it is blocked,
■ collision imminent braking system is applying the brakes,
■ radar sensor is blocked by an ice or
water film,
■ fault is detected in the radar, engine
or brake system.
When adaptive cruise control is
deactivated automatically, the control
indicator m illuminates white and a
warning symbol is displayed as a pop- up in the Driver Information Centre.
The stored speed is maintained.
9 Warning
When adaptive cruise control is
deactivated, the driver must take
over full brake and engine control.
Switching off
Press button C to switch off adaptive
cruise control. The control indicator
m extinguishes. The stored speed is
deleted.
Switching off the ignition also
switches off adaptive cruise control
and deletes the stored speed.
Driver's attention
■ Use adaptive cruise control carefully on bends or mountain
roads, as it can lose the vehicle
ahead and require time to detect it
again.
■ Do not use the system on slippery roads as it can create rapid
changes in tyre traction (wheel
spinning), so that you could lose
control.
■ Do not use adaptive cruise control during rain, snow or heavy dirt, as
the radar sensor can be covered by a water film, dust, ice or snow. This
reduces or completely suppresses
the visibility. In case of sensor
blockage, clean the sensor cover.
System limits ■ The system's automatic brake force
does not permit hard braking and
the braking level may not be
sufficient to avoid a collision.
■ After a sudden lane change, the system needs a certain time todetect the next preceding vehicle.
182Driving and operating
Hill and trailer considerations
System performance on hills and
when towing a trailer depends on
vehicle speed, vehicle load, traffic
conditions and the road gradient. It
may not detect a vehicle in your path
while driving on hills. On steep hills,
you may have to use the accelerator
pedal to maintain your vehicle speed.
When going downhill, especially
when towing a trailer, you may have
to brake to maintain or reduce your
speed.
Note that applying the brake
deactivates the system. It is not
recommended to use adaptive cruise
control on steep hills especially when towing a trailer.
Radar unit
The radar unit is mounted behind the
radiator grille below the brand
emblem.
9 Warning
The radar unit was aligned
carefully during manufacture.
Therefore, after a frontal accident, do not use the system. The front
bumper may appear to be intact,
however the sensor behind can be
out of position and react
incorrectly. After an accident,
consult a workshop to verify and
correct the adaptive cruise control
sensor position.
Settings
Settings can be changed in the Auto
collision preparation menu in the
vehicle personalisation 3 127.
Fault
If the adaptive cruise control does not
work due to temporary conditions
(e.g. blockage by ice) or if there is a
permanent system error, then a
message is displayed in the Driver
Information Centre.
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.
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, 3 127.
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.
204Driving and operating
As soon as the natural gas tank is
empty, petrol operation is
automatically engaged until the
ignition is switched off.
If the natural gas tank is not refuelled, the system must be manually
switched to petrol operation before
the engine is started-up again. This
will prevent damage to the catalytic
converter (overheating caused by
irregular fuel supply).
If the selector switch is operated
several times within a short time, a
switchover block is activated. The engine remains in the current
operating mode. The block remains
active until the ignition is switched off.
A slight loss of power and torque can be expected during petrol operation.
You must therefore adapt your driving
style (e.g. during overtaking
manoeuvres) and vehicle loads (e.g.
towing loads) accordingly.
Every six months run the petrol tank
down until control indicator Y
illuminates, then refuel. This isnecessary to maintain fuel quality as
well as system function necessary for
petrol operation.
Fill the tank completely at regular intervals to prevent corrosion in the
tank.
Fuel for liquid gas
operation Liquid gas is known as LPG
(Liquefied Petroleum Gas) or under its French name GPL (Gaz de Pétrole Liquéfié). LPG is also known as
Autogas.
LPG consists mainly of propane and
butane. The octane rating is between
105 and 115, depending on the
butane proportion. LPG is stored
liquid at around 5 - 10 bar pressure.
The boiling point depends on the
pressure and mixing ratio. At ambient pressure, it is between -42 °C (pure
propane) and -0.5 °C (pure butane).Caution
The system works at an ambient
temperature of approx. -8 °C to
100 °C.
Full function of the LPG system can only be guaranteed with liquid gas
which complies with the minimum
requirements of DIN EN 589.
Fuel selector
Pressing the LPG button switches
between petrol and liquid gas
operation as soon as the required
parameters (coolant temperature,
206Driving and operatingRefuelling9Danger
Before refuelling, switch off engine
and any external heaters with
combustion chambers. Switch off
any mobile phones.
Follow the operating and safety
instructions of the filling station
when refuelling.
9 Danger
Fuel is flammable and explosive.
No smoking. No naked flames or
sparks.
If you can smell fuel in your
vehicle, have the cause of this
remedied immediately by a
workshop.
Caution
In case of misfuelling, do not
switch on ignition.
Fuel filler flap is located at right rear
side of the vehicle.
The fuel filler flap can only be opened
if the vehicle is unlocked. Release the
fuel filler flap by pushing the flap.
Petrol and Diesel refuelling
To open, turn the cap slowly anti-
clockwise.