What occurs in an ignition system just before the spark plug fires?

In an ignition system, just before the spark plug fires, high voltage is generated in the secondary winding of the ignition coil. When the primary circuit is energized, the current flows through the primary winding of the ignition coil, creating a magnetic field. When the current is interrupted (usually by the ignition control module or points), the collapsing magnetic field induces a high voltage in the secondary winding. This high voltage is essential for producing a spark at the spark plug, which ignites the air-fuel mixture in the combustion chamber.

The process is fundamental to the operation of the ignition system, as the successful induction of high voltage into the secondary winding enables the ignition of the fuel mixture, thereby facilitating the engine's operation. Understanding this step is crucial for diagnosing ignition system performance and ensuring efficient engine function.