Ignition Coil: Description and Operation

Coil On Plug:

PURPOSE
The Coil-Per-Plug system is controlled by the Powertrain Control Module (PCM) to provide secondary spark at the correct time in the combustion process.

OPERATION
The Coil-Per-Plug system works in the same manner as a standard coil pack. The Coil-Per-Plug systems fire only one spark plug instead of two like standard coil packs. Since there is one coil on each spark plug the coils will fire the spark plugs on the compression stroke only.