Which component's function is directly related to commencing combustion in an engine?

The function of commencing combustion in an engine is primarily associated with the ignition system rather than the starting mechanism. The ignition coil plays a crucial role in this process. It transforms the battery’s low voltage into a much higher voltage necessary to create a spark at the spark plugs, which ignites the air-fuel mixture in the combustion chamber.

The fuel pump, while critical for delivering fuel to the engine, does not initiate combustion itself; it simply supplies the necessary fuel for combustion to occur. The starter motor is responsible for turning the engine over, allowing it to start running, but it is not directly responsible for the ignition or combustion process. The oil filter’s role is to clean the engine oil and ensure that lubricated parts function smoothly, which is not related to the combustion process. Therefore, the component directly involved in commencing combustion is the ignition coil.