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.
|
Diagnostic Circuit Diagram