2007 > 2.7L V6 GASOLINE >
DESCRIPTION
This specification applies to HCU(Hydraulic Control Unit) and ECU(Electronic Control Unit) of the HECU.(Hydraulic and
Electronic Control Unit)
This specification is for the wiring design and installation of ABS/TCS/ESC ECU.
This unit has the functions as follows.
a. Input of signal from Pressure sensor, Steering angle sensor, Yaw & Lateral G sensor, the wheel speed sensors
attached to each wheel.
b. Control of braking force / traction force/ yaw moment.
c. Failsafe function.
d. Self diagnosis function.
e. Interface with the external diagnosis tester.
Installation position : engine compartment a. Brake tube length from Master cylinder port to HECU inlet port should be max. 1m
b. The position should not be close to the engine block and not lower than the wheel.
OPERATION
The ECU shall be put into operation by switching on the operating voltage (IGN).
On completion of the initialization phase, the ECU shall be ready for operation.
In the operating condition, the ECU shall be ready, within the specified limits (voltage and temperature), to process the
signals offered by the various sensors and switches in accordance with the control algorithm defined by the software
and to control the hydraulic and electrical actuators.
Wheel Sensor signal processing
The ECU shall receive wheel speed signal from the four active wheel sensors.
The wheel signals are converted to voltage signal by the signal conditioning circuit after receiving current signal from
active wheel sensors and given as input to the MCU.
Solenoid Valve Control
When one side of the valve coil is connected to the positive voltage that is provided through the valve relay and the
other side is connected to the ground by the semiconductor circuit, the solenoid valve goes into operation.
The electrical function of the coils are always monitored by the valve test pulse under normal operation conditions.
Voltage limits
a.Overvoltage
When overvoltage is detected(above 16.8 V), the ECU switches off the valve relay and shuts down the system.
When voltage is returned to operating range, the system goes back to the normal condition after the initialization
phase.
b. Undervoltage
In the event of undervoltage(below 9.3 V), ABS control shall be inhibited and the warning lamp shall be turned on.
When voltage is returned to operating range, the warning lamp is switched off and ECU returns to normal operating
mode.
Pump Motor Checking
The ECU performs a pump motor test at a speed of 15km/h once after IGN is switched on.
Diagnostic Interface
Failures detected by the ECU are encoded on the ECU, stored in a EEPROM and read out by diagnostic equipment
when the ignition switch is turned on.
The diagnosis interface can also be used for testing the ECU during production of the ECU and for actuating the HCU
(Air - bleeding line or Roll and Brake Test line).
Warning Lamp module
