Operation CHARM: Car repair manuals for everyone.

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, ON-OFF control of power transistor is performed by engine control module.
- When power transistor is turned on, current flows from ignition coil (primary winding) to ground through power transistor.
- When power transistor is turned 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).