Ignition Control System Description: Notes

This system controls electronically the time of electric current flow to ignition primary coil as well as ignition timing. ECM (PCM) judges the engine and vehicle conditions by using signals from various sensors, selects the most suitable electric current flow time and ignition timing for that engine and vehicle conditions from among those prestored in its memory and sends an ignition signal to the igniter (power unit) in ignition coil assembly. Control of this system includes three different types as follows.

• Ignition timing control at engine start
• Ignition timing control after engine start
• Electric current flow time control