Fuel Pressure Regulator (FPR) & High Pressure Pump
The Gasoline Direct Injection (GDI) Engine Control Module (ECM) operates the fuel pressure control valve with the signals from the Fuel Rail Pressure Sensor (RPS) to optimize RPM and rail pressure. The high-pressure pump adds high pressure to the low-pressure fuel that was pumped from the low-pressure pump. Fuel pressure is controlled by the Fuel Pressure Regulator (FPR). Under abnormal condition of the high-pressure fuel system, the engine ECU controls the fuel system as low pressure.