Circuit Description

In a direct fuel injection system, fuel is taken from the fuel tank by the low-pressure fuel pump and delivered to the high-pressure fuel pump installed to the cylinder head. The high -pressure pump increases fuel pressure to 5-10 MPa and injects the fuel directly into the cylinders through the fuel injectors. Fuel volume in the low-pressure fuel line is maintained by the fuel pump controller in response to PWM sensor signals from the ECM. The ECM sends these signals in response to pressure sensor feedback. Under moderate temperature conditions, line pressure is maintained at a constant 350 kPa. In torrid areas, line pressure is maintained at a constant 550 kPa.

When an abnormality is detected in the low-pressure fuel delivery system, the code data is stored in memory.