Intelligent technology 132Intelligent technologyElectronic stabilisation program (ESP)The Electronic Stabilisation Program increases the car's
stability.Description
The anti-lock brake system (ABS), the electronic differential lock
(EDL) and the traction control system (ASR) are all integrated into
the electronic stabilisation program (ESP). The ESP is designed to
enhance the control over the vehicle in critical handling situations,
such as when accelerating and cornering. It reduces the tendency to
skid at all speeds under all road conditions and improves the
stability and roadholding of the vehicle. ESP helps the car to start
moving, accelerate and climb a gradient in slippery conditions
where this may otherwise be difficult or even impossible. The ESP is
switched on automatically when the engine is started. It should
normally be left switched on at all times for optimum car stability.
Driving situations
If the car is oversteering (rear wheels losing grip first) the ESP
mainly brakes the outside front wheel; if the car is understeering
(front wheels losing grip first), the ESP brakes the inside rear wheel
and possibly also other wheels. This automatic brake application is
accompanied by characteristic noises.If, when braking, one of the wheels is turning too slowly in relation
to the road speed and is close to locking up, the system will reduce
the pressure in the brake line to this wheel. The driver is made aware
of this control process by a pulsating of the brake pedal and accom-
panying noise. In this situation it is important to keep the brake
pedal fully depressed so the ABS can regulate the brake application
- do not “pump” the brake pedal. However, the ABS will not neces-
sarily guarantee shorter stopping distances in all conditions. For
instance, on loose gravel or fresh snow on top of an icy surface the
stopping distance with ABS may even be slightly longer.
Whenever it detects a significant difference in the speed of the driven
wheels of one axle (for example, if the road is slippery on one side)
the electronic differential lock (EDL) applies the brake to slow down
the spinning wheel so that more of the power is directed to the
other wheels. This function is active up to about 100 km/h. The brake
system will make noises while it is working.
If one wheel has less grip and starts spinning (for instance, if one of
the driven wheels is on ice), press the accelerator hard until the car
starts moving.
If the wheels start to spin, the traction control system (ASR) auto-
matically reduces the engine torque to match the amount of grip
available.
Activating the sport mode
If required (for instance if you want to use the launch control), you
can switch the traction control system (ASR) and electronic stabili-
sation program (ESP) to sport mode by pressing the button
once. The ESP warning lamp will light up and the message ASR off
will appear in the driver information system display. The amount of
wheel slip is regulated according to the road speed. You should only
use this feature if your driving ability and traffic conditions allow
you to do so safely.
Fig. 110 Centre
console with ESP
switch
ESP
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