Electronic Oil Pump Unit (OPU)
The automatic transmission of the vehicle equipped with the ISG system has a mechanical oil pump as well as an electric oil pump mounted on the exterior of the transmission. The electric oil pump is controlled by an oil pump unit (OPU), and supplies hydraulic pressure to the U/D brake when the vehicle stops or stops at low speed. The ISG system implements an Auto Stop/Auto Start mode by automatically shifting from D to N stage and N to D stage when restarting without an additional shift lever operation through an electric oil pump.