Intelligent technology
186Anti-lock brake system and traction control
M-ABS (ABS and TCS)Anti-lock brake system (ABS)
The anti-lock brake system prevents the wheels locking
during braking.The anti-lock brake system (ABS) is an important part of the vehicle's active
safety system.
How the ABS works
If one of the wheels is turns too slowly in relation to the road speed, and is
close to locking, the system will reduce the braking pressure for this wheel.
The driver is made aware of this control process by a pulsating of the brake
pedal and audible noise. This is a deliberate warning to the driver that one or
more of the wheels is tending to lock and the ABS control function has inter-
vened. In this situation it is important to keep the brake pedal fully depressed
so the ABS can regulate the brake application. Do not “pump”.
If you brake hard on a slippery road surface, the best possible control is
retained as the wheels do not lock.
However, ABS will not necessarily guarantee shorter braking distances in all
conditions. The braking distance could even be longer if you brake on gravel
or on fresh snow covering a slippery surface.
WARNING
•
The anti-lock brake system cannot defy the laws of physics. Slippery
and wet roads are dangerous even with ABS! If you notice that the ABS is
working (to counteract locked wheels under braking), you should reduce
speed immediately to suit the road and traffic conditions. Do not let the
extra safety features tempt you into taking any risks when driving.
•
The effectiveness of ABS is also determined by the tyres fitted
⇒ page 232.
•
If the running gear or brakes are modified, the effectiveness of the ABS
could be severely limited.
Traction control system (TCS)*
The traction control system prevents the drive wheels from
spinning when the car is accelerating.Description and operation of the traction control system during acceleration
(TCS)
TCS reduces engine power to help prevent the drive wheels of front-wheel
drive vehicles losing traction during acceleration. The system works in the
entire speed range in conjunction with ABS. If a malfunction should occur in
the ABS, the TCS will also be out of action.
TCS helps the vehicle to start moving, accelerate and climb a gradient in slip-
pery conditions where this may otherwise be difficult or even impossible.
The TCS is switched on automatically when the engine is started. If necessary,
it may be turned on or off pushing the button on the centre console.
When the TCS is off, the warning lamp is lit. The TCS should normally be left
switched on at all times. Only in exceptional circumstances, when 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 loose surfaces
•
When the vehicle is bogged-down, to free it by “rocking.”WARNING (continued)
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Intelligent technology187
Safety First
Operating instructions
Practical tips
Te c h n i c a l D a t a
The TCS should be switched on again afterwards as soon as possible.
WARNING
•
It must be remembered that 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 TCS tempt you
into taking any risks when driving, this can cause accidents.Caution
•
In order to ensure that TCS function 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, running
gear or any components affecting the wheels and tyres) could affect the effi-
ciency of the ABS and TCS.
XDS*
Driveshaft differentialWhen 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
which is turning faster (outer wheel) receives less drive torque than the inner
wheel. This may mean that in certain situations the torque provided to the
inner wheel is too high, causing the wheels to spin. On the other hand, the
outer wheel receives a lower drive torque than it could transmit. This causes
an overall loss of lateral grip on the front shaft, resulting in understeering or
“lengthening” of the path. The XDS system is able, using the ESP sensors and signals, to detect and
correct this effect.
The XDS, via the ESP, brakes the inner wheel thus counteracting the excess
drive torque in this wheel. This means that the path requested by the driver
is more precise,
The XDS system operates in combination with the ESP and is always active,
even when the traction control, TCS, is disconnected.
Electronic stabilisation programme (ESP)*General notes
The electronic stabilisation programme increases the
vehicle's stability on the road.The electronic stabilisation programme helps to reduce the danger of skid-
ding.
The electronic stabilisation programme (ESP) consists of
ABS, EDL, TCS and
Steering manoeuvre recommendations.
Electronic Stabilising Program (ESP)*
ESP reduces the danger of skidding by braking the wheels individually.
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 car is starting to skid), then the ESP compen-
sates 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.
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Intelligent technology
188Steering manoeuvre recommendations
This is a complementary safety function included in the 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 destabilize its trajectory to the right to or to the left. In this case the ESP
recognizes 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 doesn't steer itself with this function, the driver has full control of
the vehicle at all times.
WARNING
•
It must be remembered that 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 ESP tempt you
into taking any risks when driving, this can cause accidents.Caution
•
In order to ensure that 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, running
gear or any components affecting the wheels and tyres) could affect the effi-
ciency of the ABS, EDL, ESP and TCS.
Anti-lock brake system (ABS)The anti-lock brake system prevents the wheels locking during braking
⇒ page 186.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 slip-
pery conditions where this may otherwise be difficult or even impossible.
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 79.
At speeds of up to approximately 80 km/h, it is able to balance out differ-
ences 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 other
driven wheel via the differential.
To prevent the disc brake of the braking wheel from overheating, the EDL cuts
out automatically if subjected to excessive loads. The vehicle will continue to
function normally without EDL. For this reason, the driver is not informed that
the EDL has been switched off.
The EDL will switch on again automatically when the brake has cooled down.
WARNING
•
When accelerating on a slippery surface, for example on ice and snow,
press the accelerator carefully. Despite EDL, the driven wheels may start to
spin. This could impair the vehicle's stability.
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Intelligent technology189
Safety First
Operating instructions
Practical tips
Te c h n i c a l D a t a
•
Always adapt your driving style to suit road conditions and the traffic
situation. Do not let the extra safety afforded by EDL tempt you into taking
any risks when driving, this can cause accidents.Caution
Modifications to the vehicle (e.g. to the engine, the brake system, running
gear or any components affecting the wheels and tyres) could affect the effi-
ciency of the EDL ⇒ page 210.The traction control system (TCS)The traction control system prevents the drive wheels from spinning when the
car is accelerating ⇒page 186.Four-wheel drive*
On four-wheel drive models, the engine power is distributed
to all four wheelsGeneral notes
The four-wheel-drive system operates completely automatically. The propul-
sion force is distributed among the four wheels and adapted to the driving
style and the road conditions.
The four-wheel drive is specially designed to complement the superior engine
power. This combination gives the car exceptional handling and performance
capabilities – both on normal roads and in more difficult conditions, such as
snow and ice. Winter tyres
Thanks to its four-wheel drive, your car will have plenty of traction in winter
conditions, even with the standard tyres. Nevertheless, we still recommend
that winter tyres or all-season tyres should be fitted on all four wheels when
winter road conditions are expected, mainly because this will give a better
braking response.
Snow chains
On roads where snow chains are mandatory, this also applies to cars with
four-wheel drive.
Changing tyres
On vehicles with four-wheel drive, all four tyres must have the same rolling
circumference
⇒page 237.
WARNING
•
Even with four-wheel drive, you should always adjust your speed to suit
the conditions. Do not let the extra safety features tempt you into taking
any risks when driving. Failure to do so could result in an accident.
•
The braking capability of your vehicle is limited by the tyres' grip.
Vehicle behaviour is no different from a vehicle without four-wheel drive.
So do not be tempted to drive too fast on icy or slippery roads just because
the car still has good acceleration in these conditions. Failure to do so
could result in an accident.
•
On wet roads bear in mind that the front wheels may start to “aqua-
plane” and lose contact with the road if the car is driven too fast. If this
should happen, there will be no sudden increase in engine speed when
“aquaplaning” begins to warn the driver, as with a front-wheel drive car.
For this reason and for that mentioned above, always choose a driving
speed suitable for the road conditions. Failure to do so could result in an
accident.
WARNING (continued)
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Intelligent technology
190Brakes
What factors can have a negative effect on the brakes?New brake pads
New brake pads do not provide optimal performance during the first 400 km
they must be “run in”. However, the reduced braking capacity may be
compensated by pressing on the brake pedal a little harder. Avoid over-
loading the brakes during run-in.
Wear
The rate of wear on the brake pads depends a great deal on how you drive and
the conditions in which the vehicle is operated. Negative factors are, for
instance, city traffic, frequent short trips or hard driving with abrupt starts
and stops.
Wet roads; road salt
When the velocity is over 80 km/h windscreen wipers are on, the brake
system moves the pads towards the brake discs for a few seconds. This
occurs - without warning to the driver - at regular intervals and requires a
more rapid response from the brakes when driving on wet roads.
In certain conditions, such as in heavy rain, or after washing the car or driving
through water, the full braking effect can be delayed by moisture (or in winter
by ice) on the discs and brake pads. The brakes should be “dried” by pressing
the pedal to restore full braking effect.
The effectiveness of the brakes can also be temporarily reduced if the car is
driven for some distance without using the brakes when there is a lot of salt
on the road in winter. In this case, the layer of salt on the brake discs and pads
has to wear off before braking.
Corrosion
There may be a tendency for dirt to build up on the brake pads and corrosion
to form on the discs if the car is used infrequently, or if you only drive low
mileages without using the brakes very much. If the brakes are not used frequently, or if rust has formed on the disks, it is
advisable to clean off the pads and disks by braking firmly a few times from a
moderately high speed
⇒.
Faults in the brake system
If the brake pedal travel should ever increase suddenly, this may mean that
one of the two brake circuits has failed. Drive immediately to the nearest qual-
ified workshop and have the fault rectified. On the way to the dealer, be
prepared to use more pressure on the brake pedal, and allow for longer stop-
ping distances.
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is too low.
The brake fluid level is monitored electronically.
Brake servo
The brake servo amplifies the pressure you apply to the brake pedal. The
brake servo works only when the engine is running.
WARNING
•
When applying the brakes to clean off deposits on the pads and discs,
select a clear, dry road. Be sure not to inconvenience or endanger other
road users. Risk of accident.
•
Ensure the vehicle does not move while in neutral, when the motor is
stopped. Failure to do so could result in an accident.Caution
•
Never let the brakes “drag” by leaving your foot on the pedal when you do
not really intend to brake. This overheats the brakes, resulting in longer stop-
ping distances and greater wear.
•
Before driving down a long, steep gradient, it is advisable to reduce speed
and change to a lower gear (or move the selector lever to a lower gear position
if your car has automatic transmission). This makes use of engine braking
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Driving and the environment
192Driving and the environmentRunning-inRunning in a new engine
The engine needs to be run-in over the first 1,500 km.Up to 1,000 kilometres
– Do not drive faster than two thirds of top speed.
– Do not accelerate hard.
– Avoid high engine revolutions.
– Do not tow a trailer.
From 1000 to 1500 km
– Speeds can be gradually increased to the maximum road speed
or maximum permissible engine speed (rpm).During its first few hours of running, the internal friction in the engine is
greater than later on, when all the moving parts have bedded in.
For the sake of the environment
If the engine is run in gently, its life will be increased and its oil consumption,
reduced.
Braking effect and braking distance
The braking effect and braking distance are influenced by
driving situations and road conditions.The efficiency of the brakes depends directly on the brake pad wear. The rate
of wear of the brake pads depends to a great extent on the conditions under
which the vehicle is operated and the way the vehicle is driven. If you often
drive in town traffic, drive short distances or have a sporty driving style, we
recommend that you have the thickness of your brake pads checked by an
Authorised Service Centre more frequently than recommended in the Service
Schedule.
If you drive with wet brakes, for example, after crossing water areas, in heavy
rainfall or even after washing the car, the effect of the brakes is lessened as
the brake discs are wet or even frozen (in winter): The brakes should be
“dried” by pressing the pedal to restore full braking effect.
WARNING
Longer braking distances and faults in the brake system increase the risk
of accidents.•
New brake pads must be run in and do not have the correct friction
during the first 400 km. However, the reduced braking capacity may be
compensated by pressing on the brake pedal a little harder. This also
applies when new brake pads are fitted.
•
If brakes are wet or frozen, or if you are driving on roads which have
been gritted with salt, braking power may set in later than normal.
•
On steep stopes, if brakes are excessively used, they will overheat.
Before driving down a long steep stopes, it is advisable to reduce speed
and change down into a lower gear (or move the selector lever to a lower
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Driving and the environment193
Safety First
Operating instructions
Practical tips
Te c h n i c a l D a t a
gear if your vehicle has automatic transmission). This makes use of engine
braking and relieves the brakes.
•
Never let the brakes “rub” 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 as the brake servo does not function.
•
Very heavy use of the brakes may cause a vapour lock if the brake fluid
is left in the system for too long. This impairs the braking effect.
•
Non-standard or damaged front spoilers could restrict the airflow to the
brakes and cause them to overheat. Observe the relevant instructions
before purchasing accessories ⇒ page 210, “Technical modifications”.
•
If a brake circuit fails, the braking distance will be increased consider-
ably. Contact a qualified workshop immediately and avoid unnecessary
journeys.
Exhaust gasses purification systemCatalytic converter*To conserve the useful life of the catalytic converter
– Always use unleaded petrol.
– Do not let the fuel get too low in the tank.
– For engine oil changes, do not top the reservoir up ⇒ page 220,
“Topping up engine oil ”. – Never tow the vehicle to start it, use jump leads if necessary
⇒page 264.
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 qualified workshop. In general, the exhaust warning lamp will light
up when any of the described symptoms occur ⇒page 75. If this happens,
unburnt fuel can enter the exhaust system and escape into the environment.
The catalytic converter can also be damaged by overheating.
WARNING
The catalytic converter reaches very high temperatures! Fire hazard!•
Never park where the catalytic converter could come into contact with
dry grass or inflammable 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
system. These materials could catch fire when the vehicle is being driven.Caution
Never fully drain the fuel tank 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 under some conditions. This depends on
the sulphur content of the fuel used. Quite often the problem can be solved
by changing to another fuel brand.
WARNING (continued)
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Driving and the environment
194Diesel engine particulate filter*
The diesel engine particulate filter eliminates soot produced
by burning diesel.The diesel engine dust filter eliminates most of the soot from the exhaust 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. See under Warning
Lights.
WARNING
•
The diesel engine particulate filter may reach extremely high tempera-
tures; it should not enter into contact with flammable materials under-
neath the vehicle. Failure to comply could result in fire.Caution
•
The vehicle is not designed for refuelling with mixtures of FAME fuel
(biodiesel) over 7% in accordance with DIN 51628. The diesel particle filter is
damaged when this mixture percentage is exceeded.
Economical and ecological drivingEconomical and environmental drivingFuel consumption, environmental pollution and wear to the engine, brakes
and tyres depends in large part on your driving style. By adopting an econom-
ical driving style and anticipating the traffic situation ahead, you can easily reduce fuel consumption by 10-15%. Next, we provide you with some tips in
order to help reduce contamination and, at the same time, save money.
Driving ahead of the circumstances
A vehicle uses most fuel when accelerating. When you anticipate the situa-
tion, you have to brake less often and, thus, accelerate less. If it is possible,
let the vehicle roll with a gear engaged
, for example, if you see a red light
ahead. The braking effect preserves brakes and tyres from wear; the emis-
sions and fuel consumption are reduced to zero (disconnection out of
inertia).
Change gear early to save energy
An effective way of saving fuel is to change up quickly through the gears.
Running the engine at high rpm in the lower gears uses an unnecessary
amount of fuel.
Manual gearbox: Change from first to second gear as quickly as possible. We
recommend that, whenever possible, you change to a higher gear upon
reaching 2,000 rpm.
Automatic gearbox: Accelerate in moderation and avoid the “kick-down”
position.
Avoid driving at high speed
We advise you not to drive at the top speed permitted by the vehicle. Fuel
consumption, exhaust emissions and noise levels all increase very rapidly at
higher speeds. Driving at moderate speeds will help to save fuel.
Avoid idling
It is worthwhile switching off the engine when waiting in a traffic jam, at level
crossings or at traffic lights with a long red phase. The fuel saved after only
30 - 40 seconds is greater than the amount of fuel needed to restart the
engine.
The engine takes a very long time to warm up when it is running at idling
speed. Mechanical wear and pollutant emissions are also especially high
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