The factory service manual refers to it as a crankshaft position sensor, however you are right in that it can only measure engine speed. I've checked all the local auto parts stores (autozone, napa, parts plus, advanced, auto value) most of them did not even have a part listed and a couple tried to sell me the wrong part. The dodge dealer can get me one for $140, I just thought that was alot for such a simple sensor.
thanks for the replies,
Michael