Component Location
General Description
The HECU is composed of a ECU (Electronic Control Unit ) and a HCU( Hydraulic Control Unit) , so the HECU hardware includes all solenoid valves inside the unit as well as the ECU.
DTC Description
The HECU monitors the operation of the IC components such as memory, register, A/D converter and so on. The HECU 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.
DTC Detecting Condition
Item | Detecting Condition | Possible cause |
DTC Strategy | ? Internal monitoring | ? Faulty HECU |
Detect Mode | ? Initial Check ? Outside the ABS control cycle ? Inside the ABS control cycle ? Diagnosis mode ? Failure mode |
Enable Conditions | ? When the MCU can’t erase or write a data of the EEPROM. ? When the master/slave processor detects abnormal operation in RAM, status register, interrupt, timer, A/D converter and cycle time. |
Fail Safe | ? System down. The ABS/EBD functions are inhibited. - The valve relay and all solenoids are prevented from being switched on. ? The ABS/EBD warning lamps are activated. |