Q: P0401: EGR Sensor A curcuit low

My 2008 Ford f150 4.6 liter v8 is throwing a trouble code: "P0405: EGR Sensor A Circuit Low". I have replaced the EGR, erased the code, and it came back within a few miles. Please note that on this model, the "EGR pressure sensor" (aka: DPFE) is mounted permently on the EGR. Also, the only other component (i am aware of) is the "vacuum regulator". Anyway, I checked the voltage to the EGR, and here are my results -- note: all tests are KOEO with the harness plugged into the EGR -- (1). BrownWireWithGreenStripe(This is the return to the computer) 0.41 volts. (2) BrownWireWithWhiteStripe (This is the REF voltage): approximately 5 volts. To ensure the return voltage is reaching the PCM without signal loss, i tested the voltage of the return wire just before the wire enters into the PCM harness, and sure enough, the voltage is exactly 0.41v (not sure if this voltage is in spec???). I also cleaned the throttle body and checked all the vacuum hoses for blockages and/or leaks. Any ideas?

My car has 100000 miles.
My car has an automatic transmission.