Beware, some scanners may display the readings in the yellow column, so know your tool. The green column reflects the fuel pump monitor PID on a scanner. As you can see by the chart, that would send you in completely the wrong direction. For example, a 75% duty signal could be misread as 25%. 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. 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. As an additional benefit, a returnless system, having one less fuel line, reduces the chances of a fuel leak.