Ignition Coil: Description and Operation

Ignition coil:

The ignition coil contains separate ignition coils which are controlled by the Powertrain Control Module (PCM) through two coil leads. Each coil fires two spark plugs simultaneously:

- One spark plug on the compression stroke. This spark plug uses the majority of the ignition coil energy.
- One spark plug on the exhaust stroke. This spark plug uses very little of the ignition coil stored energy.

Since these two spark plugs are connected in series, the firing voltage of one spark plug will be negative with respect to ground, and the other spark plug will be positive with respect to ground.