2889564 - E7023 ESP - Description
Description
The electronic anti-lock brake system (BOSCH
5.7 ABS with ASR) governs braking pressure sent to the wheels and
prevents loss of grip under all tyre and road surface conditions.This is combined with an ESP (Electronic
Stability Program) system, which controls vehicle stability by modulating
drive torque and braking the wheels differentially, if there is
a loss of grip, thus helping to return the car to its correct trajectory.The ESP system acts on the engine and brakes
to generate a stabilising torque when the ABS sensors detect conditions
that could lead to the vehicle slipping.The ESP system includes the following
specific components over and above those of the ABS:
- a sensor which detects the steering wheel position (steering
sensor);
- a sensor which detects the vehicle's rotation around the
vertical axis and side acceleration (centrifugal force) (yaw sensor);
- a sensor that detects pressure on the hydraulic ABS unit
(pressure sensor)
The ESP system is always connected to the
ASR system.The ASR system increases vehicle stability
and active safety by controlling drive wheel slip. If slip is caused
by excessive power transmission, it cuts in to reduce engine power through
communication with the engine management control unit. if slip is
detected at a single wheel, the system cuts in to brake the slipping
wheel by acting on the modulation solenoid.ASR comes on automatically whenever the
engine is started. The system can be deactivated by operating a
button in the dashboard.When the system is off, an LED on the button
comes on at the same time as a warning light on the control panel.The ESP, on the other hand, switches on
automatically each time the engine is started up and cannot be switched
off.ASR/ESP warning light: the warning light
flashes when the system cuts in to notifiy the driver that the ASR
system has cut in due to road surface grip conditions.When th econtrol unit detects an error in
the ASR function or the ESP function, it lights up the warning light
constantly.
As far as the ABS function is concerned,
See E7020 ABS
.
For more details,
Characteristic of working principle 3340 A(B.S. ANTI-LOCK BRAKING
SYSTEM .)The supply lines for the control unit and
the various system components (sensors and actuators) are protected
by a special maxifuse, located near the control unit, and by a fuse in
the engine compartment in the relay and fuse box.The ASR off button is protected by a special
shunt fuse, located next to the junction unit.