Crankshaft Position Sensor: Operation
WARNING: This page is about a different car, the 2006 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
The crankshaft position and engine speed are detected contactless signal (hall effect). The distance between the crankshaft position sensor and the teeth of the driven plate is fixed by the installation position.
When the crankshaft rotates, an alternating voltage is generated in the crankshaft position sensor by the teeth of the driven plate.
In this case, the front edge of a tooth generates a positive voltage pulse and the rear edge a negative voltage pulse. The distance from the positive to the negative voltage peak equals the length of a tooth.
The gap created by 2 missing teeth (arrow) has the effect that no voltage is generated in the crankshaft position sensor. This is analyzed in order to detect the TDC position of cylinder 1.