DTC P0091: Fuel Pressure Regulator 1 Control Circuit Low: General Description
WARNING: This page is about a different variant/trim than selected.
GDI ECM operates fuel pressure control valve with the signal from fuel rail pressure sensor to control optimized RPM and rail pressure.
High pressure pump adds high pressure to low pressure fuel from low pressure pump. Controlling fuel pressure is done by fuel pressure regulator from 40 to 150 bar. Under the abnormal condition of high pressure fuel system, ECM controls fuel system as low pressure.