Probable Causes

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.

Momentary loss of power to the PCM or FICM: Defective power relays, shorted or open harness, intermittent connectors, poor grounds.
Momentary short to ground of VREF: Shorted harness or connector, damaged sensor (sensors that use VREF include - exhaust pressure (EP) sensor, injection control pressure (ICP) sensor, manifold absolute pressure (MAP) sensor, barometric pressure (BARO) sensor, accelerator pedal position (APP) sensor, exhaust gas recirculation (EGR) sensor.