DTC P1235-13: High Pressure Fuel Pump Circuit Open [12/2019 - 10/2022]: Description

The high-pressure direct injection fuel system consists of a spill control valve, check valve, fuel relief valve, fuel pressure sensor, fuel pump assembly (for high pressure side) and fuel injector assemblies (for direct injection). The spill control valve adjusts the return volume of the high-pressure fuel. The check valve mechanically opens and closes the paths to the fuel delivery pipes. The relief valve releases the fuel back to the fuel tank if the high-pressure fuel system malfunctions. The fuel pump assembly (for high pressure side) is installed to the cylinder head cover and operated by a cam installed to the end of the intake camshaft. Rotation of the camshaft moves the pump plunger inside the fuel pump assembly (for high pressure side) up and down, pressurizing the fuel. The pressurized fuel opens the check valve and is pumped into the fuel delivery pipe.