A car igniter is a component in the car's engine that is responsible for sending a signal from within the distributor to the ignition coil, making the spark plugs fire. It is also known as the ignition control module.
The igniter or ignition control module can be located inside the distributor or may be a separate component on its own. In some applications, the unit is also responsible for advancing or retarding the engine's timing. Potential signs of a failing igniter include sputtering, stalling and difficulty starting the car. Because the igniter is responsible for firing the spark plugs, when the unit fails, the engine fails to start.