[Boghog]

The primary ignition components include the coil primary circuit, the power transistor, and the ignition switch. When the ignition switch is turned on, it charges the primary coil windings. When the engine is running, the powertrain control module (PCM) sends a signal to the power transistor. The power transistor grounds the negative side of the coil primary circuit, generating the proper voltage in the secondary circuit which induces spark.​