According to my Haynes manual,
"This sensor is a permanent magnetic variable reluctance sensor..."
But it has me wondering. The sensor has three wires; a ground, a wire with 5 volts, and a wire with 8 volts (according to the manual).

Now, I had a jeep that really did have a permanent magnet variable reluctance sensor (crankshaft position sensor). It had only two wires.
Such a sensor has a permanent magnet and a coil in it. When the metal tooth whips by, it jerks on the magnetic field and causes a pulse in the coil.

So why have three wires, two of them with voltage? Because Dodge actually uses an electromagnet instead of a permanent magnet?

I know the Haynes manual has other mistakes in it, so I really don't rely on it to get every little thing right. Maybe just a lazy writer stuck the word "permanent magnet" in there. So I'd really like to know the scoop, because I have to fix mine. I know a trick that works on a reluctance sensor with a magnet weakened by the years of heat and vibration -- just wire a .01 uF capacitor across the wires to the sensor. I fixed the jeep that way.

1994 Ram 2500 automatic 4X4