Fuel Pump Electrical Circuit Diagnosis

Fuel System Diagnosis:

SYSTEM DESCRIPTION
The fuel pump fuse provides system voltage to the fuel pump relay. The PCM grounds the Fuel Pump Relay control circuit to energize the fuel pump relay. When the ignition is turned ON, the PCM commands the fuel pump relay ON for at least 2 seconds, voltage is applied to the electric fuel pump and will continue to energizes the fuel pump after the PCM receives 3X reference pulses. The fuel pump is an electric pump and is part of the Modular Fuel Sender Assembly. The fuel pump supplies fuel through an in-line fuel filter, fuel rail assembly to the fuel injectors. A fuel pressure regulator, attached to the fuel rail assembly, maintains a regulated fuel pressure for correct operation of the fuel injectors. Any unused fuel is then returned to the fuel tank by a separate fuel return pipe.