Ignition System Description 3.8L

The electronic ignition system controls fuel combustion by providing a spark to ignite the compressed air/fuel mixture at the correct time. To provide optimum engine performance, fuel economy, and control of exhaust emissions, the PCM controls the spark advance of the ignition system. The electronic ignition system does not use the conventional distributor and coil. The electronic ignition system has the following advantages over the conventional mechanical distributor system:

The electronic ignition system consists of three twin-tower ignition coils, an ignition control module, a dual Hall-effect crankshaft position sensor, an engine crankshaft balancer with interrupter rings attached to the rear, related connecting wires, and the Ignition Control (IC) and fuel metering portion of the PCM.

The three twin-tower ignition coils are individually mounted to the ignition control module. Each end of a coils secondary winding is attached to a spark plug. Each cylinder is paired with the cylinder that is opposite it. These two spark plugs are on top dead center at the same time. When the ignition coil fires, both plugs fire at the same time to complete the circuit. The cylinder on compression is said to be the event cylinder and the one on exhaust is the waste cylinder. The cylinder on the exhaust stroke requires very little of the available energy to fire the plug. The remaining energy will be used as required by the cylinder on the compression stroke. The same process is repeated when the cylinders reverse roles. This method of ignition is called a waste spark ignition system.

The electronic ignition system consists of the following components:

For a more complete and detailed description of the above information refer to Electronic Ignition (EI) System Description in Engine Controls-3.8L

Ignition System Description 5.7L

The electronic ignition system controls fuel combustion by providing a spark to ignite the compressed air/fuel mixture at the correct time. To provide optimum engine performance, fuel economy, and control of exhaust emissions, the PCM controls the spark advance of the ignition system. The electronic ignition system does not use the conventional distributor and coil. The electronic ignition system has the following advantages over a conventional mechanical distributor system:

The ignition system on this vehicle feature a multiple coil ignition and is known as coil near plug. The secondary ignition wires are short compared with a distributor ignition system wire. Eight ignition coils/module are individually mounted above each cylinder on the rocker covers. The coil/modules are fired sequentially. There is an Ignition Control (IC) circuit for each ignition coil/module. The eight ignition control circuits are connected to the PCM. All timing decisions are made by the PCM, which triggers each coil/module individually.

The electronic ignition system consists of the following components:

For a more complete and detailed description of the above information refer to Electronic Ignition (EI) System Description in Engine Controls-5.7L