Ignition Coil: Description and Operation

Fig. 1 Ignition Coil:

Fig. 3 Ignition Coil Sectional:

The ignition coil provides the high tension spark to ignite the fuel / air mixture in each cylinder.

The ignition coil pack contains three separate ignition coils which are controlled by the igniter through three coil leads. Each ignition coil ignites two spark plugs simultaneously, one spark in the compression stroke and one on the exhaust stroke.

The spark plug ignited on the exhaust stroke uses very little of the ignition coil's stored energy, the majority being used on the compression stroke. Since these two spark plugs are connected in series, the igniting voltage of one spark plug will be negative with respect to ground, while the other will be positive with respect to ground.