Sort of to do with EFI (more electronics)

[Brad Sheridan]

>    The oil temperature, water temperature, oil pressure sensors use
>what range of voltage? It is my understanding that they ground a "12V"
>signal and the resulting current flow is used as the measure of sensor
>range. Is this true for all the sensors?

   Most of the more accurate pressure sensors I've seen are powered with
three wires, +12, GND, and signal. The output range is 0-6V, and linear.
They are rated either PSIG or PSIA. The G and A stand for Gage and
Absolute. Gage means relative to ambient pressure, while the absolute means
the output will be in terms of absolute pressure. The less expensive single
wire senders as used stock on some cars(VWs being the ones I've dealt with)
are resistive as you describe.

Brad