Diagnostic Aids

Perform this test when directed by QUICK TEST. This test is only intended to diagnose the following components and circuits.

Fuel Pump Relay
Inertia Fuel Shutoff (IFS) Switch
Warning Light
Wiring Harness Circuits (FPC & FPM)
PCM

Fuel Pump Control (FPC) circuit from PCM is used to energize fuel pump relay. With ignition on, fuel pump relay is energized for 20 seconds and whenever engine RPM is detected. Fuel Pump Monitor (FPM) circuit is downstream of Inertia Fuel Shutoff (IFS) switch and is used by PCM to monitor voltage going to fuel pump.

Fig 1: Identifying Fuel Pump Monitor Control Circuits (Econoline)

Courtesy of FORD MOTOR CO.

Fig 2: Identifying Fuel Pump Monitor Control Circuits (Excursion & F250-550)

Courtesy of FORD MOTOR CO.