What is a distributor reluctor?

A distributor reluctor, also known as a reluctor wheel or trigger wheel, is a component in an ignition system that helps determine the position of the engine's crankshaft or camshaft. It typically consists of a series of notches or teeth that pass by a pickup sensor, generating a signal that informs the ignition control module when to fire the spark plugs. This precise timing is crucial for optimal engine performance and efficiency. Reluctors are commonly found in both traditional distributors and modern distributor-less ignition systems (DIS).