Which component is responsible for multiplying battery voltage to create a spark?

The ignition coil is the component responsible for multiplying battery voltage to create a spark in the engine's ignition system. It functions by converting the low voltage from the vehicle's battery, typically around 12 volts, into a much higher voltage, usually between 15,000 and 45,000 volts or more. This high voltage is necessary to produce a spark capable of jumping the gap of the spark plug and igniting the air-fuel mixture within the combustion chamber.

This process is critical for the engine’s operation, as it ensures that the proper ignition timing occurs, allowing the engine to run smoothly and efficiently. The ignition coil is typically triggered by the ignition control module or the electronic control unit, which determines when to generate the high voltage pulse needed for firing the spark plug.

Regarding the other components mentioned, the distributor cap is part of a system that routes the high voltage from the ignition coil to the appropriate spark plug but does not itself increase voltage. The starter motor is responsible for cranking the engine to start it but is not involved in generating a spark. The fuel injector is responsible for delivering fuel to the engine and does not play any role in creating the necessary spark for ignition. Hence, the ignition coil is the key component in this process.