General Information

Automatic Transaxle
P1777 OPU Power control circuit failure - General Information

Component Location





General Description

The HEV uses the hydraulic pressure that in addition to mechanical main hydraulic pump, EOP(Electric oil pump) controlled by OPU(oil pump unit) to take command from by PCM/TCM generates to operate engine clutch and U/D brake.
While low speed driving or engine auto stop regardless of driving mode (EV mode or HEV), when hydraulic pressure become low because of mechanical main hydraulic pump rotation in low speed or stop, OPU supplies hydraulic pressure on U/D brake by operating EOP in order to protect Friction Element.
When shifting the driving mode from EV mode to HEV mode, EOP supplies hydraulic pressure to the engine clutch in order to use engine power when the driving mode shift is completed (Engine clutch : wet type multiple disk clutch that connect or disconnect the engine power between engine input shaft and transaxle input shaft)

DTC Description

This DTC is set and sent to PCM/TCM when OPU detect error into OPU internal power control circuit.

DTC Detecting Condition





Signal Waveform & Data








Fig 1) Channel A : OPU Status, Channel B : HALL Signal (Normal situation)
Fig 2) Channel A : OPU Status, Channel B : HALL Signal (PWM motor speed line error and can line error too)
















Ex) Operation
Fig 1) Number of Oil Pump at key on situation
Fig 2) Number of Oil Pump when is driven compulsory
Fig 3) Channel A : OPU Status, Channel B : HALL Signal (At key on situation)
Fig 4) Channel A : OPU Status, Channel B : HALL Signal (When is driven compulsory)