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Transporting children safely
176
Note
Store the remaining part of the belt for the “Top Tether” system in a textile
pocket, which is located at the child seat.
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Driving Tips
Intelligent Technology
Electronic stability programme (ESP)*
General
General
The ESP aids you maintain control of your vehicle in situations in border-
line driving situations such as when negotiating a curve too fast. The risk
of skidding is reduced and your car thus offers greater driving stability
depending on the conditions of the road surface. This occurs at all speeds.
The following systems are integrated into the electronic stability
programme:
•Electronic Differential Lock (EDL),
•Traction control system (TCS),
•Antilock brake system (ABS),
•Brake Assist.
Operating principle
The ESP switches on automatically when the engine is started and then
conducts a self-test. The ESP control unit processes data from the indi-
vidual systems. It also processes additional measurement data which are
supplied by highly sensitive sensors: the rotational velocity of the vehicle
about its vertical axis, the lateral acceleration of the vehicle, the braking
pressure and the steering angle.
The direction which the driver wishes to take is determined based on the
steering angle and the speed of the vehicle and is constantly compared
with the actual behaviour of the vehicle. If differences exist, such as the
car beginning to skid, the ESP will automatically brake the appropriate
wheel.
The car is stabilised again by the forces which take effect when the wheel
is braked. Intervention into the brake system takes place primarily on the
outer front wheel of a vehicle which tends to oversteer (tendency for the
rear of the vehicle to break away) while occurs this is on the inner rear
wheel of a vehicle which tends to understeer (tendency to shift out of the
curve). This braking control cycle is accompanied by noises.
The ESP operates in combination with the ABS ⇒page 181, “Antilock
brake system (ABS)*”. If there is a fault in the ABS system, the ESP also
does not operate.
Fig. 145 ESP switch
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The ESP warning light ⇒page 35 lights up in the instrument cluster when
there is a fault on the ESP.
Switching off
You can switch the ESP off and on again as you wish, by pressing the
button ⇒page 177, fig. 145 . The ESP warning light ⇒page 35 lights up
in the instrument cluster when the ESP is switched off.
The ESP should normally always be switched on. It may be good practice
in certain exceptional cases, such as when you wish to have wheel slip,
to switch off the system.
Examples:
•when driving with snow chains,
•when driving in deep snow or on a loose surface,
•when it is necessary to rock a car free when it has become stuck.
Then you should switch on the ESP again.
WARNING
It is also not possible for the E SP to overcome the physical limits
of the vehicle. Even if a vehicle fitted with ESP you should still
always adapt your style of driving to the condition of the road
surface and the traffic situation. This particularly applies when
driving on slippery and wet roads. The increased safety offered
must not tempt you to take greater risks than otherwise - risk of an
accident!
Note
•All four wheels must be fitted with the same tyres in order to achieve
problem-free operation of the ESP. Differing rolling circumferences of the
tyres can lead to an undesirable reduction in the engine output.
•Changes to vehicle (e.g. on engine, on the brakes, on chassis or other
assignment of tyres and wheels) can influence the function of the ESP
⇒ page 232, “Accessories, changes and replacement of parts”.
Traction control system (TCS)*
The traction control system prevents the driven wheels
from spinning when accelerating.
General
The TCS makes it much easier, and sometimes at all possible, to start off,
accelerate and climb a steep hill when the conditions of the road surface
are unfavourable.
Operating principle
The TCS switches on automatically when the engine is started and then
conducts a self-test. The system monitors the speeds of the driven wheels
with the aid of the ABS sensors. If the wheels are spinning, the force trans-
Fig. 146 TCS switch
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mitted to the road surface is automatically adapted by reducing the engine
speed. This occurs at all speeds.
The TCS operates in combination with the ABS
⇒page 181, “Antilock
brake system (ABS)*”. The TCS will not f unction if a fault exists in the ABS
system.
The TCS warning light ⇒page 34 lights up in the instrument cluster when
there is a fault on the TCS.
Switching off
You can switch the TCS off and on again as you wish by pressing the
button ⇒page 178, fig. 146 . The TCS warning light ⇒page 34 lights up
in the instrument cluster when the TCS is switched off.
The TCS should normally always be switched on. It may be good practice
in certain exceptional cases, such as when you wish to have wheel slip,
to switch off the system.
Examples:
•when driving with snow chains,
•when driving in deep snow or on a loose surface,
•when it is necessary to rock a car free when it has become stuck.
then you should switch on the TCS again.
WARNING
You should always adjust your style of driving to the conditions of
the road surface and the traffic situation. The increased safety
offered must not tempt you to take greater risks than otherwise -
risk of an accident!
Note
•All four wheels must be fitted with the same tyres in order to achieve
problem-free operation of the TCS. Differing rolling circumferences of the
tyres can lead to an undesirable reduction in the engine output.
•Changes to vehicle (e.g. on engine, on the brakes, on chassis or other
assignment of tyres and wheels) can influence the function of the TCS
⇒ page 232, “Accessories, changes and replacement of parts”.
Electronic Differential Lock (EDL)*
The electronic differential lock prevents an individual
wheel from slipping.
Models fitted with ESP are equipped with electronic differential lock (EDL).
General
The EDL makes it much easier, and sometimes at all possible, to start off,
accelerate and climb a steep hill when the conditions of the road surface
are unfavourable.
Operating principle
The EDL is activated automatically, that is without any action on the part
of the driver. It monitors the speeds of the driven wheels with the aid of the
ABS sensors. Should only one drive wheel begin spinning on a slippery
surface there will be an appreciable difference in the speed of the driven
wheels. The EDL function brakes the slipping wheel and the differential
transmits a greater driving force to the other driven wheel. This control
process is also accompanied by noises.
Overheating of the brakes
The EDL switches off automatically if unusually severe stresses exist in
order to avoid excessive heat generation in the disc brake on the wheel
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180
which is being braked. The vehicle can continue to be driven and has the
same characteristics as a vehicle not fitted with EDL.
The EDL switches on again automatically as soon as the brake has cooled
down.
WARNING
•Depress the accelerator carefully when accelerating on
uniformly slippery road surfaces, such as ice and snow. The driven
wheels might still spin despite the EDL and affect the stability of the
vehicle - risk of an accident!
•You should always adapt your style of driving to the condition
of road surface and to the traffic situation even when your vehicle
is fitted with EDL. The increased safety offered must not tempt you
to take greater risks than otherwise - risk of an accident!
Note
•If the ABS or TCS or ESP warning li ght comes on, this may also indi-
cate a fault in the EDL. Please have the car inspected as soon as possible
by a specialist garage.
•Changes to vehicle (e.g. on engine, on the brakes, on chassis or other
assignment of tyres and wheels) can influence the function of the EDL
⇒ page 232, “Accessories, changes and replacement of parts”.
Brakes
What has a negative effect on braking efficiency?
Wear-and-tear
Wear-and-tear to the brake pads is greatly dependent on the operating
conditions of the vehicle and your style of driving. Particularly if you drive a great deal in towns and over short distances or if you adopt a sporty style
of driving, it may be necessary to have the thickness of the brake pads
inspected at a specialist garage between the service inspections.
Wet roads or road salt
There may be a certain delay before the brakes take full effect under
certain conditions such as when driving through water, during heavy rain
showers or after the vehicle has been washed in an automatic vehicle
wash, since the brake discs and brake pads may be moist or even have a
coating of ice on them in winter. You should dry the brakes as soon as
possible (by applying and releasing the brakes several times, if the road
conditions and the traffic situation allows it).
There also may be a certain delay before the full braking efficiency is avail-
able when driving on roads which have been treated with road salt if you
have not used the brakes for some considerable time beforehand. The
layer of salt on the brake discs and brake pads must first be rubbed off
when you apply the brakes.
Corrosion
Corrosion on the brake discs and dirt on the bake pads occur if the vehicle
has been parked for a long period and if you do not make much use of the
braking system.
We recommend cleaning the brake discs by firmly applying the brakes at
a fairly high speed if you do not make much use of the braking system or
if surface corrosion is present
⇒.
Faults in the brake surface
If you notice that the braking distance has suddenly become longer and
that the brake pedal can be depressed further, it is possible that a brake
circuit of the dual-circuit brake system has failed. Drive, in such cases, to
the nearest specialist garage without delay in order to have the problem
rectified. Drive at a reduced speed while on your way to the dealer and
adapt your style of driving to the higher brake pedal pressure required.
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Low brake fluid level
An insufficient level of brake fluid may result in problems in the brake
system. The level of the brake fluid is monitored electronically
⇒page 36,
“Brake system ”.
WARNING
•Only apply the brakes for the purpose of drying and cleaning the
brake discs if the traffic conditions permit this. Do not place any
other road users in jeopardy.
•When retrospectively mounting a front spoiler, solid wheel hubs
etc. one must ensure that the air supply to the front wheel brakes
is not reduced otherwise the braking system could run too hot.
•Allow for the fact that new brake pads do not achieve their full
braking efficiency until approximately 200 kilometres. New brake
pads must be first “run in” before they develop their optimal fric-
tion force. You can, however, compensate for this slightly reduced
braking force by increasing the pressure on the brake pedal. This
guideline also applies to any new brake pads installed at a future
date.
Caution
•Never allow the brakes to rub by applying slight pressure if you do not
wish to brake the vehicle. This causes the brakes to overheat and can also
result in a longer braking distance and excessive wear.
•Before negotiating a steep downhill section, please reduce your speed
and shift down into the next lower gear (manual gearbox) or select a lower
driving stage (automatic gearbox). This enables you to make full use of
the braking power of the vehicle and reduces the strain on the brakes. Any
additional braking should be done intermittently, not continuously.
Brake booster
The brake booster boosts the pressure which you generate with the brake
pedal. The necessary pressure is only generated when the engine is
running.
WARNING
•Never switch off the engine before the vehicle is stationary.
•The brake booster only operates when the engine is running.
Greater physical effort for braking is required when engine is
switched off. Because if you do not stop as normal, this can cause
an accident and severe injuries.
Antilock brake system (ABS)*
ABS prevents the wheels locking when braking.
General
The ABS contributes significantly to enhancing the active safety of your
vehicle. Compared to a car not fitted with the ABS brake system, you are
able to retain optimal steering ability even during a full brake application
on a slippery road surface because the wheels do not lock up.
You must not expect, however, that the braking distance will be shorter
under all circumstances as a result of the ABS. The braking distance for
example on gravel and fresh snow, when you should anyway be driving
slowly and cautiously, will be longer.
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Operating principle
As soon as the vehicle speed has increased to about 20 km/hour an auto-
matic test procedure is conducted during which you will be able to hear a
pumping noise for about 1 second.
The brake pressure will be reduced on a wheel which is rotating at a speed
which is too low for the speed of the vehicle and tending to lock. This
control cycle is noticeable from a pulsating movement of the brake
pedal which is accompanied by noises. This is consciously intended to
provide the driver with the information that the wheels are tending to lock
(ABS control range). You must always keep the brake pedal depressed to
enable the ABS to optimally control the brake application in this braking
range. Never interrupt the application of the brakes!
WARNING
•The ABS can also not overcome the physical limits of your
vehicle. Please do not forget this, particularly when driving on icy
or wet road surfaces. If the ABS is operating within the control
range, adapt your speed immediately to the conditions of the road
surface and the traffic situation. The increased safety offered by
the ABS must not tempt you to take greater risks than otherwise -
risk of an accident!
•The normal braking system is still fully functional if there is an
ABS fault. Visit a specialist garage as quickly as possible and
adjust your style of driving to ta ke account of the ABS fault in the
meantime since you will not know how great the damage is.
Note
•A warning light comes on if a fault occurs in the ABS system
⇒ page 35.
•Changes to vehicle (e.g. on engine, on the brakes, on chassis or other
assignment of tyres and wheels) can influence the function of the ABS
⇒ page 232, “Accessories, changes and replacement of parts”.
Brake Assist*
During a severe brake application (e.g. if a hazard exists), the Brake
Assist increases the braking force and thus makes it possible to rapidly
produce the pressure required in the brake system.
The majority of drivers do apply the brakes in good time in dangerous situ-
ations, but do not depress the brake pedal with sufficient pressure. Conse-
quently, it is not possible for the car to achieve its maximum deceleration
and the car covers a greater distance than necessary.
The Brake Assist is activated by the very quick operation of the brake
pedal. In such cases, a much greater braking pressure exists than during
a normal brake application. This makes it possible, even with a relatively
low resistance of the brake pedal, to produce an adequate pressure in the
brake system in the shortest possible time, which is required for maximum
deceleration of the car. You must apply the brake pedal firmly and hold it
in this position in order to achieve the shortest possible braking distance.
The Brake Assist is able to help you achieve a shorter braking distance in
emergency situations by rapidly producing the pressure required in the
brake system. It fully exploits the attributes of the ABS. After you release
the brake pedal, the function of the Brake Assist is automatically switched
off and the brakes operate in the normal way.
The Brake Assist is part of the ESP system. If a fault occurs in the ESP,
the Brake Assist function is also not available. Further information on the
ESP ⇒page 177.
WARNING
•The Brake Assist is also not able to overcome the physical
limits of your car in terms of the braking distance required.
•Adapt your speed to the conditions of the road surface and to
the traffic situation.
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•The increased safety offered by the Brake Assist must not tempt
you to take a greater safety risk than otherwise.
Power steering*
The power steering enables you to steer the vehicle with less physical
force.
The steering characteristics can be changed by a specialist garage.
You will place great stresses on the power steering system if the steering
is turned to full lock when the vehicle is stationary. Turning the steering to
full lock in such a situation will be accompanied by noises.
It is still possible to fully steer the vehicle if the power steering fails or if the
engine is not running (vehicle being towed in). The only difference is that
greater physical effort is required.
It is possible that the hydraulic pump of the power steering will not run due
to the low vehicle network voltage if the battery has gone flat and the
engine must started with the help off jump leads. This condition will be
indicated by lighting up of the warning light.
The power steering operates again if the battery is charged to a specific
range when engine is running. It also operates again, if the engine can be
started with its own battery.
Caution
Do not leave the steering at full lock for more than 15 seconds when the
engine is running - risk of damaging the power steering!
Note
Have the steering inspected as soon as possible by a specialist garage if
there is a leak or fault in the system.
Tyre inflation pressure-control system*
The tyre inflation pressure-control system compares with the aid of the
ABS sensors the speed and also the roll ing circumference of the individual
wheels. If the inflation pressure and therefore the rolling circumference of
a wheel has changed significantly, the warning light
lights up in the
dash panel ⇒page 34. The tyre inflation pressure-control system func-
tions late or too sensitively if:
•the structure of the tyre is damaged,
•the vehicle is loaded to one side or with a load on the roof,
WARNING (continued)
Fig. 147 Button for
setting the tyre infla-
tion pressure control
value
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