Question about sensors and voltage

[MustangGT1990]

I have always read/been told that the reference voltage for most sensors (Throttle position sensor, coolant temperature sensor, EGR position sensor) is approximately 5 volts. Is this true? Also, my understanding is the computer supplies this 5 volts, is that correct? When I measure mine with the KeyOnEngineOff that is what I get, 5 volts reference voltage for all of the above mentioned sensors.

*IF* this is correct, here is where my problems start. If I put my T-5 in NEUTRAL and measure the same voltages they read 2.45 volts. My understanding was they were supposed to read 5 volts reference voltage at all times. I know this sounds stupid but if my T-5 is in 1,2,3,4,5, OR R they ALL measure 5 volts. BUT if it is in NEUTRAL they all read 2.45 volts.

What I need to know is if the reference voltage is supposed to stay at 5 volts at all times?

Thank you!