Ignition System: Description and Operation

The ignition system used on this engine will not use a conventional mechanical distributor. It will be referred to as a distributor-less ignition system. The ignition coils are individually fired, but each coil is a dual output. The ignition system is controlled by the powertrain control module (PCM).

The ignition system consists of:
- Spark Plugs
- Ignition Coil Packs containing individual coils
- Secondary Ignition Cables
- Powertrain Control Module (PCM)
- Also to be considered part of the ignition system are certain inputs from the Crankshaft Position, Camshaft Position, Throttle Position and MAP Sensors.

The ignition system is controlled by the PCM. The PCM opens and closes the ignition coil ground circuit (or circuits) to operate the ignition coil (or coil packs). This is done to adjust ignition timing, both initial (base) and advance, and for changing engine operating conditions.

The amount of electronic spark advance provided by the PCM is determined by five input factors: engine coolant temperature, engine rpm, intake manifold temperature, manifold absolute pressure and throttle position.