Fuel Pump Control Module

NOTE: The Mustang 5.4L uses 2 fuel pump control modules to control fuel for the fuel delivery system. The PCM outputs only one fuel pump duty cycle on the fuel pump control (FPC) circuit. Both fuel pump control modules use this circuit. The PCM individually monitors the fuel pump control modules through the FPM and FPM2 circuits. The fuel pump control module located on the driver side of the luggage compartment is referred to as Fuel Pump Control Module 1 and the fuel pump control module located on the passenger side of the luggage compartment is referred to as Fuel Pump Control Module 2.

The fuel pump control module receives a duty cycle signal from the PCM and controls the fuel pump operation in relation to this duty cycle. The PCM requests low or high speed fuel pump operation depending on engine fuel demand. The fuel pump control module controls the fuel pump by switching the fuel pump power circuit ON and OFF at the required duty cycle. The fuel pump control module sends diagnostic information to the PCM on the fuel pump monitor (FPM) circuit. For additional information on the fuel pump control and the fuel pump monitor, refer to FUEL SYSTEMS .

On vehicles with gasoline direct fuel injection, the high pressure fuel system may be under vacuum after several hours of cold soak. Fuel vapor may collect at the fuel injection pump, causing a long start condition. To prevent this, the fuel pump relay is energized for 1 or 2 seconds, depending on application, as soon as the dome light is commanded ON. This causes the fuel pump control module and the fuel pump to cycle for 1 or 2 seconds and purge any trapped air or fuel vapor from the high pressure fuel system.