Description & Operation: Description: Notes

Ignition coil works as a transformer which converts the battery voltage to 30kv or above to ignite the spark plug inside the cylinder.

Ignitor inside the ignition plug includes power transistor. This electronic switch is controlled by the signals from the ECM (Engine Control Module).

Ignition timing is controlled by ECM. The average ignition timing in regard to the engine operating condition is memorized in ECM.

Engine operating condition (speed, load, temperature) is detected by multiple sensors.

Based on the sensor signal and the ignition timing data, ECM sends the signal to the ignition coil for a certain time. Current then flows in the ignitor and the primary coil to form magnetic force.

When the ECM ignition signal shuts off the current flowing into the primary coil, mutual induction causes sudden change in magnetic flux. The magnetic flux is then conducted to the second coil, and the turns ratio of the coil creates high voltage.

Created high voltage is discharged by destroying an electric field between the spark plug gap, thus forming an ignition.