Ignition Coil: Description and Operation

PURPOSE
- The ignition coils are triggered by the Powertrain Control Module that controls the coil primary turn on and turn off times. When the coil primary is turned off, high voltage is created in the secondary coil winding.

- This high voltage is then transferred by a coil wire to the prospective cylinder and used to ignite the air fuel mixture in the combustion chamber at a preferred time.

OPERATION
- The ignition coil activates two spark plugs simultaneously. One spark plug fires on the compression stroke which uses the majority of the ignition coil stored energy, one spark plug fires on the exhaust stroke which uses very little of the ignition coils stored energy.

- The next time the coil is fired, the situation is reversed. The next pair of spark plugs fire according to the engine firing order.