Diagnostic Aids

WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

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
Wiring Harness Circuits (FPC & FPM)
PCM

The fuel pump relay is internal to the central junction fuse box. The fuel pump relay cannot be removed or accessed; if the fuel pump relay is determined to be faulty, the central junction fuse box must be replaced. The Fuel Pump Control (FPC) is the control circuit from the Powertrain Control Module (PCM) used to energize the fuel pump relay. At key on, the relay is energized for 20 seconds, and all the time when RPM is detected. The Fuel Pump Monitor (FPM) circuit is downstream of the inertia switch and is used by the PCM to monitor voltage going to the fuel pump.

Fig 1: Identifying Central Junction Box Connector C270A Terminals

Courtesy of FORD MOTOR CO.

Fig 2: Identifying Central Junction Box Connector C270F Terminals

Courtesy of FORD MOTOR CO.

Fig 3: Identifying Inertia Fuel Shutoff Switch Connector Terminals (Excursion)

Courtesy of FORD MOTOR CO.

Fig 4: Identifying Inertia Fuel Shutoff Switch Connector Terminals (Pickup)

Courtesy of FORD MOTOR CO.