Ignition System: Description and Operation

GENERAL DESCRIPTION
The ignition system is a distributorless ignition system. Its consists of the parts as described and has an electronic ignition control system.
- ECM (or PCM)
It detects the engine condition through the signals from the sensors, determines the most suitable ignition timing and time for electricity to flow to the primary coil and sends a signal to the igniter (in ignition coil assembly).
- Ignition coil assembly (including an igniter and an ignition coil)
The ignition coil assembly has a built-in igniter and ignition coil which turns ON and OFF the primary current of the ignition coil according to the signal from ECM (or PCM). When the ignition coil primary current is turned OFF, a high voltage is induced in the secondary wiring.
- Spark plug , high-tension cord and noise suppressor
- CMP sensor, TP sensor, ECT sensor, MAF sensor and other sensors/switches.

Although this ignition system does not have a distributor, it has two ignition coil assemblies (one is for No.1 and No.4 spark plugs and the other is for No.2 and No.3 spark plugs). When an ignition signal is sent from ECM (or PCM) to the igniter in the ignition coil assembly for No.1 and No.4 spark plugs, a high voltage is induced in the secondary coil. Then, it is fed to No.1 spark plug through high-tension cords and to No.4 spark plug directly from ignition coil assembly to cause both of these plugs to spark simultaneously. Likewise, when an ignition signal is sent from ECM (or PCM) to the ignition coil assembly for No.2 and No.3 spark plugs, a high voltage is induced in the secondary coil. Then, it is fed to No.3 spark plug through high-tension cords and to No.2 spark plug directly from ignition coil assembly to cause both No.2 and No.3 spark plugs to spark simultaneously.