The crankshaft position sensor is an electrical device used to measure the rate at which the crankshaft is spinning. The reason for the crankshaft position sensor is to send information to computer to control the ignition and amount of fuel injected into the engine. If there is no reading when you test the sensor, the device has malfunctioned. One of the reasons that the crankshaft position sensor can fail is because it burns out; this is common as it is exposed to particularly high temperatures. Another reason that the crankshaft position sensor fails is because it can wear out; this happens naturally over time as a result of engine fluid or oil leaking onto it and preventing a signal being submitted.