Crankshaft Reluctor Wheel
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The crankshaft reluctor wheel is part of the crankshaft. The reluctor wheel has seven machined notches, six of which are equally spaced 60 degrees apart. The seventh notch is spaced 10 degrees after one of the 60-degree notches. The 10-degree notch is used to synchronize the engine position, while the other notches are used to provide cylinder location during a revolution.