Ignition System: Description and Operation

Ignition System Construction

The ignition system is a direct ignition system. It consists of the parts as described below and has an electronic ignition control system.
- ECM
It detects the engine and vehicle conditions 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 (power unit) in the ignition coil assembly.
- Ignition coil assembly (including an igniter and an ignition coil)
The ignition coil assembly has a built-in igniter which turns ON and OFF the current flow to the primary coil according to the signal from ECM. When the current flow to the primary coil is turned OFF, a high voltage is induced in the secondary coil. One ignition coil is in charge of ignition of one cylinder only.
- Spark plug and noise suppressor
- CMP sensor (Camshaft position sensor) and CKP sensor (Crankshaft position sensor)
Using signals from these sensors, ECM identifies the specific cylinder whose piston is in the compression stroke, detects the crank angle and engine speed, adjusts the ignition timing automatically.
- TP sensor, ECT sensor, MAP sensor, MAF sensor, IAT sensor, knock sensor, wheel speed sensor (VSS) and other sensors / switches

This ignition system does not have a distributor and high-tension cords but each cylinder has an ignition coil assembly (igniter and ignition coil) and the secondary voltage which occurred in the ignition coil is sent to the spark plug directly.