Ignition System: 6.0L

Ignition timing and spark distribution are controlled by PCM according to sensor inputs. Ignition timing is controlled primarily as a function of engine load and speed. Engine load is sensed by 2 Manifold Absolute Pressure (MAP) sensors. Engine speed is sensed by a Crankshaft Position (CKP) sensor (may also be known as engine speed sensor or flywheel sensor) located behind the flywheel.

CKP sensor at front of engine (TDC sensor), monitors crankshaft location. This information is sent to PCM to control fuel injection pulse and ignition timing. The PCM processes inputs from the sensors and accesses ignition timing from the ignition timing strategy. Engine is equipped with 2 ignition coil packs. Each ignition coil pack contains 3 separate ignition coils which are controlled by an ignition amplifier. Each ignition coil ignites 2 spark plugs simultaneously, one spark plug is ignited on compression stroke and one on exhaust stroke.

The ignition amplifiers receive ignition signals from PCM and controls the primary current of the ignition coils. Switching of the current generates high voltage at secondary windings of ignition coils. Ignition monitoring circuit senses primary current of ignition coils and informs PCM that correct ignition has occurred. If information indicates incorrect ignition, PCM stops fuel injection.