from looking at the diagrams I posted you can see that G/R wire turn in to a B/R wire that runs in to the ECU at location 3D. If we look back a few chapters in the FSM under Fuel and Emissions we can see that 3D is indeed an output. We also see that it should be below 2v at idle. So we have answered half your question. We also see that it "pushes" 12v on ignition switch on. This 12v surge is to prime the fuel lines, hence it would make sense that it as the TPS changes in resistance it raises the voltage to the fuel pump until the finally at WOT the fuel pump is seeing 12-14v