TIBURON(GK) >2006 > G 2.7 DOHC > Brake System > ESP(Electronic Stability Program) System>Description and Operation | ![]() ![]() |
Optimum driving safety
now has a name : ESP, the Electronic Stability Program.
ESP is based on the MGH
25 ABS Hydraulic System. ESP recognizes critical driving conditions, such
as panic reactions in dangerous situations, and stabilizes the vehicle by
wheel-individual braking and engine control intervention with no needfor
actuating the brake or the gas pedal.
ESP adds a further
function known as Active Yaw Control (AYC) to the ABS, TCS, EBD and EDC
functions. Whereas the ABS/TCS function controls wheel slip during braking
and acceleration and, thus, mainly intervenes in the longitudinal
dynamicsof the vehicle, active yaw control stabilizes the vehicle about
its vertical axis.
This is achieved by
wheel individual brake intervention and adaptation of the momentary engine
torque with no need for any action to be taken by the driver.
ESP essentially consists
of three assemblies : the sensors, the electronic control unit and the
actuators.
The electronic control
unit incorporates the technological experience accumulated in connection
with the MK 20 system, but has been substantially expanded in terms of
capacity and monitoring concept in order to permit the additional sensor
signals and arithmetic operations to be processed and converted into
corresponding valve, pump and engine control commands. Two 16-bit
processors and one 8-bit processor, which monitor each other, cooperate to
handle these requirements.
Of course, the stability
control feature works under all driving and operating conditions. Under
certain driving conditions, the ABS/TCS function can be activated
simultaneously with the ESP function in response to a command by the
driver.
In the event of a
failure of the stability control function, the basic safety function, ABS,
is still maintained.
DESCRIPTION OF ESP CONTROL
ESP system includes
ABS/EBD, TCS and AYC function.
ABS/EBD function The ECU
changes the active sensor signal (current shift) coming from the four
wheel sensors to the square wave.By using the input of above signals, the
ECU calculates the vehicle speed and the acceleration & deceleration
of the four wheels.And, the ECU judges whether the ABS/EBD should be
actuated or not.
TCS function prevents
the wheel slip of drive direction by adding the brake pressure and engine
torque reduction via CANcommunication.TCS function uses the wheel speed
sensor signal to determine the wheel slip as far as ABS
function.
AYC function prevents
unstable maneuver of the vehicle. To determine the vehicle maneuver, AYC
function uses the maneuver sensor signals(Yaw Rate Sensor, Lateral
Acceleration Sensor, Steering Wheel Angle Sensor).If vehicle maneuver is
unstable (Over Steer or Under Steer), AYC function applies the brake
pressure on certain wheel, and send engine torque reduction signal by
CAN.
After the key-on, the
ECU continually diagnoses the system failure. (self-diagnosis)If the
system failure is detected, the ECU informs driver of the system failure
through the BRAKE/ABS/ESP warning lamp. (fail-safe warning)
INPUT AND OUTPUT DIAGRAM
EXTERNAL DIAGRAM
ABS Warning Lamp module
The active ABS warning
lamp module indicates the self-test and failure status of the ABS .The ABS
warning lamp shall be on:
EBD Warning Lamp module
The active EBD warning
lamp module indicates the self-test and failure status of the EBD.However,
in case the Parking Brake Switch is turned on, the EBD warning lamp is
always turned on regardless of EBD functions.The EBD warning lamp shallbe
on:
ESP Warning Lamp (ESP system)
The ESP warning lamp
indicates the self-test and failure status of the ESP.
The ESP warning lamp is
turned on under the following conditions :
ESP Function Lamp (ESP system)
The ESP function lamp
indicates the self-test and operating status of the ESP.
The ESP Function lamp
operates under the following conditions :
ESP On/Off Switch (ESP system)
The ESP On/Off Switch
shall be used to toggle the ESP function between On/Off states based upon
driver input.
The On/Off switch shall
be a normally open, momentary contact switch.Closed contacts switch the
circuit to ignition.
Initial status of the
ESP function is on and switch toggle the
state. |