Depending on your setting, your readings could get reversed. Be mindful of the trigger setting on your tool. The yellow column represents the duty cycle that you may see if you tapped into the FPDM monitor circuit to the PCM with a duty cycle meter or an oscilloscope. However, as simple as that may sound, reading them requires knowledge of your own tool. There are only three diagnostic monitor signals that the FPDM will return to the PCM. So you not only get to look at the system from the PCM’s “eyes,” you also get to see it through the FPDMs “eyes” too. The nice thing about diagnostics on this system is that you have two control modules that are both reporting diagnostic information. Any of those signals from the PCM will result in zero fuel pump operation. The PCM will not send those duty cycles unless something has gone terribly wrong inside the PCM, or unless a technician commands the PCM to send those duty cycles via a suitable scan tool. As for the duty cycles that fall between the cracks - 0% to 4%, 51% to 67%, and from 82.5% to 100% - they are invalid. However, the FPDM will accept 67.5% to 82% as a valid “off” command. If the PCM wants the fuel pump turned off, it will send a 75% duty cycle to the FPDM. For example, a duty cycle from the PCM of 20% will equal 40% of fuel pump full-on, and a duty cycle of 50% would equal 100% of full-on at the pump. Whatever the PCM’s duty cycle is, multiply that by “2” and that is the fuel pump’s on percentage. In this range, the fuel pump output is directly proportional to the fuel pump’s “on” time. Between 5% and 50% duty cycle is the normal range of demands from the PCM to the FPDM.
2005 EXPEDITION FUEL PUMP LOCATION DRIVER
To achieve its goal, the PCM communicates a duty cycle to the fuel pump driver module (FPDM). The fuel pump relay is now toggled by the ignition switch.
One notable change however, is the PCM no longer controls the fuel pump relay. One Ford-specific component that still remains after more than two decades is the inertia fuel cut-off switch. A couple of things that become optional across other makes that Ford still includes are the fuel pump relay and the in-line fuel filter. This much should remain the same for any electronic returnless system.
This system consists of a rotary vane fuel pump (same as before), fuel line (pressure only), fuel rail pressure sensor (that also contains a temperature sensor), fuel pump control module and, of course, the PCM. With an electronic returnless system, the PCM can now raise or lower fuel pressure at will. Also, making it electronically pressure controlled gives the PCM more flexibility over fuel control by adding another option if needed. Roll the floor jack out from under the Expedition and then reconnect the negative battery cable to the battery.As an additional benefit, a returnless system, having one less fuel line, reduces the chances of a fuel leak.
2005 EXPEDITION FUEL PUMP LOCATION FULL
Reconnect the fuel pump wiring harness, fuel lines and fuel filler neck before raising the tank to the full height.īolt the gas tank retaining straps back into position with the socket set.
Place the gas tank back onto the floor jack, roll it back under the Expedition and then raise it back into position. Tighten the retaining ring in reverse of how you removed it. Lower the new pump down into the tank, making sure to position the fuel level float in such a way that it does not contact the side of the tank. Lift the old fuel pump up and out of the gas tank. You’ll want to turn the ring counterclockwise. Wrap the rag around the tip of the screwdriver, place the tip against the fuel pump retaining ring and tap the handle of the screwdriver with the rubber mallet until the retaining ring turns loose. Roll the tank out from under the Expedition and set it on the ground. Lower the gas tank down using the floor jack, making sure to keep it level. Disconnect the fuel filler neck from the tank also using the screwdriver. The pump is in the top-center of the gas tank. Lower the tank several inches until you can reach your arm between the tank and the bottom of the Expedition.ĭisconnect the fuel pump wiring and fuel lines from the fuel pump by hand. Unbolt the gas tank retaining straps using the socket set.