The HECU is composed of a ECU (Electronic Control Unit ) and a HCU( Hydraulic Control Unit) , HCU is composed of a source of hydraulic pressure and modulator valve block.
Increase and decrease of hydraulic pressure is opreated by electronic motor, According to a detected signal by wheel speed sensor.
The hydraulic pressure which is needed for control is supplied by pump.
The HCU’ function which is composed of a accumulator, return pump, solenoid valve is to increase, decrease or maintain the hydralic pressure supplied to a wheel cylinder by operating return pump according to HECU control signal while ABS control.
The HECU monitors the operation of the IC components such as memory, register, A/D converter and so on.
The ECU sets this code when the EEPROM data read by the master processor is different than prior data writed, or when the master/slave processor detects abnormal operation in RAM, Status Register, Interrupt, Timer, A/D converter or cycle time.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● Internal monitoring | ● Faulty HECU |
Case1 | Monitoring Period | ● Continuous |
Enable Conditions | ● If Internal control unit failures of the master/slave processor or peripheral integrated circuits is detected. | |
Case2 | Monitoring Period | ● Directly after ignition on, during reading of EEPROM-values |
Enable Conditions | ● Failure is set if checksum not correct or PSW-EEPROM-Handler reported unknown failure during EEPROM-value reading. ● If EEPROM reading sequence take longer then 3s, a failure is set. | |
Fail Safe | ● The ABS/EBD/ESP functions are inhibited. ● The ABS/EBD/ESP warning lamps are activated. |
