Intelligent Technology
214
The ESP operates in combination with the ABS ⇒page 218, “Antilock
brake system (ABS)”. If there is a fault in the ABS system, the ESP also
does not operate.
The ESP warning light ⇒page 40 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 213, fig. 180 . The ESP warning light ⇒page 40 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 270, “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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Intelligent Technology215
Using the systemSafetyDriving TipsGeneral MaintenanceBreakdown assistanceTechnical Data
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 ESP warning light comes on, this may also indicate 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 270, “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-
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 218, “Antilock
brake system (ABS)”. The TCS will not function if a fault exists in the ABS
system.
Fig. 181 TCS switch
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Intelligent Technology
220
Tyre inflation pressure-control system*
The tyre inflation pressure-control system compares with the aid of the
ABS sensors the speed and also the rolling circumference of the individual
wheels. If the rolling circumference of a wheel is changed, the warning
light
lights up in the dash panel insert ⇒page 38. The rolling circumfer-
ence of the tyre can change if:
•the tyre inflation pressure is too low,
•the structure of the tyre is damaged,
•the vehicle is loaded on one side,
•the wheels of an axle are loaded heavily (e.g. when towing a trailer or
when driving uphill or downhill),
•snow chains are mounted,
•the temporary spare wheel is mounted,
•one wheel per axle was changed. Basic setting of tyre inflation pressure-control system
After changing the tyre inflation pressures or after changing one or several
wheels, the button for the tyre inflation pressure-control system must be
pressed long enough until an acknowledegment tone sounds when the
ignition is switched on.
•Inflate all tyres to the specified inflation pressure
⇒page 264.
•Switch on the ignition.
•Press the button ⇒ fig. 182 long enough, until an acknowledg-
ment tone sounds, which confirms the storage of the basic values. As long
as the button
is pressed, the warning light lights up in the instru-
ment .
Warning light
lights up
If the tyre inflation pressure of at least one wheel is insufficiently inflated
in comparison to the stored basic value, the warning light
⇒ lights
up.
Warning light
flashes
If the warning light flashes, there is a system fault. Have the vehicle
inspected by your nearest specialist garage.
WARNING
•When the warning light lights up, immediately reduce the
speed and avoid sudden steering and brake manoeuvres. Please
stop the vehicle without delay at the nearest possible stop and
inspect the tyres and their inflation pressures.
•The driver is responsible for the correct tyre inflation pressures.
For this reason, the tyre inflation pressures must be checked regu-
larly.
•Under certain circumstances (e.g. sporty style of driving, wintry
or unpaved roads) the warning light can be delayed or does not
light up at all.
Fig. 182 Button for
setting the tyre infla-
tion pressure control
value
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Fuses and light bulbs
292
Certain electrical components are only standard on certain vehicle model
versions or only suppliable as optional equipment for certain models.
No.Power consumerAmperes
F1Control unit for convenience functions20
F2Windshield wiper lever and turn signal light lever5
F3Measuring circuit5
F4Valves for ABS30
F5Control unit for automatic gearbox15
F6Instrument cluster5
F7Not assigned
F8Radio15
F9Phone5
F10Engine control unit, Main relay5
F11Control unit for auxiliary heating20
F12Control unit for CAN databus5
F13Engine control unit25/30
F14Ignition20
F15Lambda probe, NOx-sensor, Fuel pump relay15
F16Pump for ABS30
F17Horn15
F18Amplifier for digital sound processor30
F19Front window wiper30
F20Not assigned5
F21Lambda probe15
F22Clutch pedal switch, brake pedal switch5
F23Secondary air pump
Air mass meter
Fuel high pressure pump5
10
15
F24Activated charcoal filter, exhaust gas recirculation
valve10
F25Right lighting system40
F26Left lighting system40
F27Secondary air pump
Preglowing40
50
F28Power suppy terminal 15, Starter40
F29Power supply terminal 3050
F30Te r m i n a l Xa)40
a)In order not to drain the battery unnecessarily when starting the engine, the elec-
trical components of this terminal are automatically switched off.
No.Power consumerAmperes
s24s.book Page 292 Thursday, November 24, 2005 12:27 PM