Specifications for Dakota 4WD V8-47L VIN N Crankshaft Position Sensor - Page 2525
CKP Sensor Operation And Tonewheel
On this engine, a tonewheel is bolted to the engine crankshaft. This tonewheel has sets of notches at its outer edge.
The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.