Ignition System: Description and Operation

- Turn ignition switch to "ON" position, and battery voltage will be applied to primary winding of ignition coil.
- When crankshaft position sensor and camshaft position sensor signal is input to engine control module, engine control module makes ON-OFF control of power transistors one by one.
- When power transistor is turned on, current flows from ignition coil (primary winding) to ground through power transistor.
- When power transistor is turned from OFF, high voltage is generated in primary winding of ignition coil which induces even higher voltage in the secondary winding, causing a spark at the spark plug(s).