182Intelligent technology
Practical Tips
Intelligent technology
Brakes Brake servo
The brake servo increases the pressure you apply to the brake pedal. It
works only when the engine is running .
If the brake servo is not functioning due to a malfunction, or if the vehicle
has to be towed, you will have to press the brake pedal considerably harder
to make up for the lack of servo assistance.
WARNING
The braking distance can also be affected by external factors.
● Never let the vehicle coast with the engine switched off. Failure to do
so could result in an accident. The braking distance is increased consid-
erably when the brake servo is not active.
● If the brake servo is not working, for example when the vehicle is be-
ing towed, you will have to press the brake pedal considerably harder
than normal.
Hydraulic Brake Assist (HBA)*
The Hydraulic Brake Assist function (HBA) is only included in
vehicles with ESC (ESP).
In an emergency, most drivers brake in time, but not with maximum force.
This results in unnecessarily long braking distances.
This is when the brake assist system comes into action. When pressing the
brake pedal rapidly, the assistant interprets it as an emergency. It then very
quickly builds up the full brake pressure so that the ABS can be activated
more quickly and efficiently, thus reducing the braking distance.
Do not reduce the pressure on the brake pedal. The brake assist system
switches off automatically as soon as you release the brake.
Emergency braking warning
If the vehicle is braked suddenly and continuously at a speed of more than
80 km/h, the brake light flashes several times per second to warn vehicles
driving behind. If you continue braking, the hazard warning lights will come
on automatically when the vehicle comes to a standstill. They switch off au-
tomatically when the vehicle starts to move again.
184Intelligent technology
The ASR (TCS) is connected automatically when the engine starts. If neces-
sary, it may be turned on or off pushing the button on the centre console.
When the ASR (TCS) is disconnected, the warning lamp OFF
lights up. The
TCS should normally be left on. Only in exceptional circumstances, when the
slipping of the wheels is required, should it be disconnected, for example
● With compact temporary spare wheel.
● When using the snow chains.
● When driving in deep snow or on soft terrain.
● When the vehicle is bogged-down, to free it by rocking.
The TCS should be switched on again as soon as possible.
WARNING
● Remember that the ASR (TCS) cannot defy the laws of physics. This
should be kept in mind, particularly on slippery and wet roads and when
towing a trailer.
● Always adapt your driving style to suit the condition of the roads and
the traffic situation. Do not let the extra safety afforded by ASR (TCS)
tempt you into taking any risks when driving.
CAUTION
● To ensure that the ASR (TCS) functions correctly, all four wheels must be
fitted with the same tyres. Any differences in the rolling radius of the tyres
can cause the system to reduce engine power when this is not desired.
● Modifications to the vehicle (e.g. to the engine, the brake system, run-
ning gear or any components affecting the wheels and tyres) could affect
the efficiency of the ABS and ASR (TCS). XDS*
Driveshaft differential
When taking a bend, the driveshaft differential mechanism allows the outer
wheel to turn at a higher speed than the inner wheel. In this way, the wheel
that is turning faster (outer wheel) receives less drive torque than the inner
wheel. This may mean that in certain situations the torque delivered to the
inner wheel is too high, causing the wheels to spin. On the other hand, the
outer wheel is receiving a lower drive torque than it could transmit. This
causes an overall loss of lateral grip on the front axle, resulting in under-
steer or “lengthening” of the trajectory.
By using the ESC (ESP) sensors and signals, the XDS system is able to de-
tect and correct this effect.
Through the ESC (ESP), the XDS brakes the inner wheel, thereby counteract-
ing the excess drive torque in this wheel. This means that the driver's de-
sired trajectory is much more precise,
The XDS system operates in combination with the ESC (ESP) and is always
active, even when the traction control ASR (TCS) is disconnected.
Electronic Stability Control ESC (ESP) *
General notes
The Electronic Stability Control increases the vehicle's stabil-
ity on the road. The Electronic Stability Control helps reduce the danger of skidding.
The Electronic Stability Control ESC (ESP) includes the ABS, EDL, ASR (TCS)
and Steering manoeuvre recommendations.
185
Intelligent technology
Electronic Stability Control ESC (ESP)*
The ESC (ESP) reduces the danger of skidding by braking the wheels indi-
vidually.
The system uses the steering wheel angle and road speed to calculate the
changes of direction desired by the driver, and constantly compares them
with the actual behaviour of the vehicle. If the desired course is not being
maintained (for instance, if the vehicle is starting to skid), then the ESC
(ESP) compensates automatically by braking the appropriate wheel.
The forces acting on the braked wheel bring the vehicle back to a stable
condition. If the vehicle tends to oversteer, the system will act on the front
wheel on the outside of the turn.
Steering manoeuvre recommendations
This is a complementary safety function included in the ESC (ESP). This
function aids the driver to better stabilize the vehicle in a critical situation.
For example, in case of sudden braking surface with varied adherence, the
vehicle will tend to destabilise its trajectory to the right or to the left. In this
case the ESC (ESP) recognises the situation and helps the driver with a
counter steering manoeuvre from the power steering.
This function simply provides the driver with a recommended manoeuvre in
critical situations.
The vehicle does not steer itself with this function, the driver has full control
of the vehicle at all times.
WARNING
● Remember that ESC (ESP) cannot defy the laws of physics. This
should be kept in mind, particularly on slippery and wet roads and when
towing a trailer.
● Always adapt your driving style to suit the condition of the roads and
the traffic situation. Do not let the extra safety afforded by ESC (ESP)
tempt you into taking any risks when driving.
CAUTION
● To ensure that the ESC (ESP) functions correctly, all four wheels must be
fitted with the same tyres. Any differences in the rolling radius of the tyres
can cause the system to reduce engine power when this is not desired.
● Modifications to the vehicle (e.g. to the engine, the brake system, run-
ning gear or any components affecting the wheels and tyres) could affect
the efficiency of the ABS, EDL, ESC (ESP) and ASR (TCS).
Anti-lock brake system (ABS)
The anti-lock brake system prevents the wheels locking during braking
⇒ page 183.
Electronic differential lock (EDL)*
The electronic differential lock helps prevent the loss of trac-
tion caused if one of the driven wheels starts spinning.
EDL helps the vehicle to start moving, accelerate and climb a gradient in
slippery conditions where this may otherwise be difficult or even impossi-
ble.
The system will control the revolutions of the drive wheels using the ABS
sensors (in case of an EDL fault the warning lamp for ABS lights up)
⇒ page 84.
At speeds of up to approximately 80 km/h, it is able to balance out differen-
ces in the speed of the driven wheels of approximately 100 rpm caused by a
slippery road surface on one side of the vehicle. It does this by braking the
wheel which has lost traction and distributing more driving force to the oth-
er driven wheel via the differential.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
190Driving and the environment
WARNING (Continued)
● On steep slopes, if brakes are excessively used, they will overheat.
Before driving down a long steep slope, it is advisable to reduce speed
and change down into a lower gear or range (depending on the type of
transmission). This makes use of engine braking and relieves the brakes.
● Never let the brakes “drag” by applying light pressure. Continuous
braking will cause the brakes to overheat and the braking distance will
increase. Apply and then release the brakes alternately.
● Never let the vehicle run with the engine switched off. The braking
distance is increased considerably when the brake servo is not active.
● If the brake fluid loses its viscosity and is subjected to heavy use, va-
pour bubbles can form in the brake system. This reduces the efficiency of
the brakes.
● Non-standard or damaged front spoilers could restrict the airflow to
the brakes and cause them to overheat. Before purchasing accessories
please observe the relevant instructions ⇒ page 208, Technical modifi-
cations.
● If a brake circuit fails, the braking distance will be increased consider-
ably. Contact a specialised workshop immediately and avoid unnecessa-
ry journeys.
Exhaust gas purification system Catalytic converter*
To maintain the useful life of the catalytic converter
– Use only unleaded petrol with petrol engines, as lead damages
the catalytic converter.
– Do not let the fuel get too low in the tank. –
For engine oil changes, do not replenish with too much engine
oil ⇒ page 222, Topping up engine oil .
– Never tow the vehicle to start it, use jump leads if necessary
⇒ page 263.
If you notice misfiring, uneven running or loss of power when the vehicle is
moving, reduce speed immediately and have the vehicle inspected at the
nearest specialised workshop. In general, the exhaust gas warning lamp
will light up when any of the described symptoms occur ⇒ page 77. If this
happens, unburnt fuel can enter the exhaust system and escape into the en-
vironment. The catalytic converter can also be damaged by overheating.
WARNING
The catalytic converter reaches very high temperatures! There is a risk of
fire.
● Never park where the catalytic converter could come into contact with
dry grass or flammable materials under the vehicle.
● Do not apply additional underseal or anti-corrosion coatings to the
exhaust pipes, catalytic converter or the heat shields on the exhaust sys-
tem. These materials could catch fire when the vehicle is being driven.
CAUTION
Never run the fuel tank completely dry because the irregularity of the fuel
supply may cause ignition problems. This allows unburnt fuel to enter the
exhaust system, which could cause overheating and damage the catalytic
converter.
For the sake of the environment
Even when the emission control system is working perfectly, there may be a
smell of sulphur from the exhaust gas under some conditions. This depends
on the sulphur content of the fuel used. Quite often the problem can be
solved by changing to another brand of fuel.
191
Driving and the environment
Diesel engine particulate filter*
The diesel engine particulate filter eliminates soot produced
by burning diesel.
Fig. 136 Vehicle data
sticker on back cover of
the Maintenance Pro-
gramme
Your vehicle is fitted with a DPF (Diesel particulate filter) if the vehicle data
sticker (back cover of the “Maintenance Programme”) lists the PR code 7GG
or 7MG ⇒ fig. 136.
The diesel engine particulate filter eliminates most of the soot from the ex-
haust gas system. Under normal driving conditions, the filter cleans itself. If
the driving conditions do not allow the filter to clean itself (for example,
multiple short trips) the filter will be obstructed by dust and pollen and the
indicator for the diesel engine particulate filter indicator will light up.
This does not represent a fault, it is a warning that indicates that the filter
has not been able to regenerate automatically and that you must carry out a
cleaning cycle, as indicated in ⇒ page 83.
WARNING
● The diesel engine particulate filter may reach extremely high temper-
atures; the vehicle should be parked so that the exhaust pipe does not
come into contact with flammable materials underneath the vehicle. Oth-
erwise there is a risk of fire.
CAUTION
● Your vehicle is not designed to use biodiesel fuel. Never, under any cir-
cumstances refuel with biodiesel. The use of biodiesel fuel could damage
the engine and the fuel system. The addition of biodiesel to diesel by the
diesel producer in accordance with standard EN 590 is authorised and will
not cause damage to the engine or the fuel system.
● Using diesel fuel with a high sulphur content may significantly reduce
the working life of the diesel particulate filter. Your Authorised Service Cen-
tre will be able to tell you which countries have diesel with a high sulphur
content.
Economical and environmentally friendly
driving
Economical and environmentally friendly driving
Fuel consumption, environmental pollution and wear to the engine, brakes
and tyres depends in large part on your driving style. By adopting an eco-
nomical driving style and anticipating the traffic situation ahead, you can
easily reduce fuel consumption by 10-15%. Some tips on how to help you
reduce pollution while saving money are listed below.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
196Trailer towing
Ball coupling of towing bracket*
Depending on the model version, the spherical head on the trailer hook
may be found in the tool box.
The ball coupling is provided with instructions on fitting and removing the
ball coupling of the towing bracket.
WARNING
The towing bracket ball coupling must be stored securely in the luggage
compartment to prevent them being flung through the vehicle and caus-
ing injury.
Note
● By law, the ball coupling must be removed if a trailer is not being towed
and it obscures the number plate.
Driving tips
Driving with a trailer always requires extra care. Weight distribution
The weight distribution of a loaded trailer with an unladen vehicle is very
unfavourable. However, if this cannot be avoided, drive extra slowly to allow
for the unbalanced weight distribution.
Speed
The stability of the vehicle and trailer is reduced with increasing speed. For
this reason, it is advisable not to drive at the maximum permissible speed
in an unfavourable road, weather or wind conditions. This applies especially
when driving downhill. You should always reduce speed immediately if the trailer shows the slight-
est sign of
snaking. Never try to stop the “snaking” by increasing speed.
Always brake in due course. If the trailer has an overrun brake, apply the
brakes gently at first and then, firmly. This will prevent the jerking that can
be caused by the trailer wheels locking. Select a low gear in due course be-
fore going down a steep downhill. This enables you to use the engine brak-
ing to slow down the vehicle.
Reheating
At very high temperatures and during prolonged slopes, driving in a low
gear and high engine speed, always monitor the coolant temperature gauge
⇒ page 55.
Electronic Stability Control*
The ESC (ESP)* system helps to stabilise the trailer in case of skidding or
rocking.
Fitting a towing bracket*
It is possible to fit a towing bracket to the rear of the vehicle.
199
Vehicle maintenance and cleaning
Vehicle maintenance and cleaning General notes
Regular washing and care help maintain the value of your
vehicle.Vehicle maintenance
Regular care and washing help to maintain the value of the vehicle. This
may also be one of the requirements for acknowledging warranty claims in
the event of bodywork corrosion or paint defects.
The best way to protect your vehicle against the harmful effects of the envi-
ronment is through correct maintenance and frequent washing. The longer
substances such as insect remains, bird droppings, resinous tree sap, road
dirt, industrial deposits, tar, soot or road salt and other aggressive materi-
als remain on the vehicle, the more damage they do to the paintwork. High
temperatures (for instance in strong sunlight) further intensify the corrosive
effect.
After winter, a period when salt is put on the roads, it is important to have
the underside of the vehicle washed thoroughly.
Products for vehicle maintenance
Car care products are available in your Authorised Service Centre. Keep the
product instructions until you have used them up.
WARNING
● Car care products can be toxic. Because of this, they must always be
kept closed in their original container. Keep them out of the reach of chil-
dren. Failure to comply could result in poisoning.
● Always read and observe the instructions and warnings on the pack-
age before using vehicle care products. Improper use could cause health
problems or damage the vehicle. The use of certain products may pro-
duce noxious vapours; they should be used in well ventilated areas.
● Never use fuel, turpentine, engine oil, nail varnish remover or other
volatile fluids. These are toxic and highly flammable. Risk of fire and ex-
plosion.
● Before washing your vehicle, or carrying out any maintenance, switch
the engine off, apply the handbrake firmly and remove the key from the
ignition.
CAUTION
Never attempt to remove dirt, mud or dust if the surface of the vehicle is dry.
Never use a dry cloth or sponge for cleaning purposes. This could damage
the paintwork or the windows of your vehicle. Soak dirt, mud or dust with
plenty of water.
For the sake of the environment
● When purchasing products for your vehicle maintenance, select the
ones which are not harmful to the environment.
● The waste from car care products should not be disposed of with ordina-
ry household waste. Observe the disposal information on the package.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
200Vehicle maintenance and cleaning
Care of the vehicle exterior
Automatic car wash tunnel
The vehicle can normally be washed without problem in an
automatic car wash.
The vehicle paintwork is so durable that the vehicle can normally be washed
without problems in an automatic car wash tunnel. However, the paintwork
wear depends to a large extent on the kind of the car wash tunnel, the
brushes used, its water filtering and the type of cleaning and preservative
products.
Before going through a vehicle wash, be sure to take the usual precautions
such as closing the windows and sunroof.
If the vehicle has special accessories such as spoilers or a roof rack or two-
way radio aerial, etc., it is advisable to consult the car wash tunnel operator.
After washing, the brakes could take some time to respond as the brake
discs and pads could be wet, or even frozen in winter. Dry the brakes by
braking several times.
WARNING
Water, ice and salt on the brakes can reduce braking efficiency. Risk of
accident.
CAUTION
If an automatic car wash tunnel is used, before entering the tunnel, put the
aerial down parallel to the roof and do not tighten to avoid damage. Washing by hand
Vehicle washing
–
First soften the dirt and rinse it off with water.
– Clean your vehicle from top to bottom with a soft sponge, a
glove or a brush. Use very light pressure.
– Rinse the sponge or glove often with clean water.
– Special car shampoo should only be used for very stubborn dirt.
– Leave the wheels, sill panels etc. until last, using a different
sponge or glove.
– Rinse the vehicle thoroughly with water.
– Dry the vehicle surface gently with a chamois leather.
– In cold temperature, dry the rubber seals and their surfaces to
prevent them from freezing. Apply silicone spray to the rubber
seals.
After washing the vehicle
– After washing, avoid sudden and sharp braking. “Dry” the
brakes by braking several times ⇒ page 189, Braking capacity
and braking distance.