System Description

When ignition is on, Powertrain Control Module (PCM) will activate in-tank fuel pump. In-tank fuel pump will remain ON as long as engine is cranking or running and PCM is receiving ignition reference pulses. If there are no ignition reference pulses, PCM will turn in-tank fuel pump OFF 2 seconds after ignition is turned ON or 2 seconds after engine stops running. In-tank fuel pump is an electric pump attached to fuel sender assembly. Fuel pump is designed to provide fuel at a pressure above pressure needed by fuel injectors. A fuel pressure regulator, attached to fuel rail, keeps fuel available to fuel injectors at a regulated pressure. Unused fuel is returned to fuel tank by a separate fuel return pipe.