185Starting and driving
Electronic Stability
Program (ESP) 3
Anti-skid system
The Electronic Stability Program employs
both the antilock braking system (ABS) and
the traction control system (TCS). It is a
system that helps the driver to stabilize the
car in unusual circumstances that can oth-
erwise be difficult to handle.
How the ESP system works
The Electronic Stability Program can help to
prevent the car from skidding by braking
one or several wheels independently of the
driver. The engine output is then also
reduced to prevent the driving wheels from
spinning. The car has sensors that measure
wheel speed, yaw rate, lateral acceleration,
steering wheel position and braking pres-
sure. The values provided by these sensors
are used to calculate the actual direction of
the car, the intentions of the driver and
whether the ESP should be engaged.
If this direction does not agree with that
intended by the driver, calculated from the
steering wheel position, the ESP is
engaged.
The ESP improves the driver’s chances
of retaining control over the car in a critical
situation.
WARNING
When driving normally, the ESP system
helps to improve the car’s directional
stability. The ESP must not be regarded
as a system to enable the driver to main-
tain higher speeds. The same precau-
tions must be adopted as normal for safe
cornering and driving on slippery roads
must be adopted.
Illustration of how the system applies the
brakes on one or several wheels in order
to reduce the likelihood of the car skidding
93U SM 06.book Page 185 Friday, February 18, 2005 1:15 PM