Ignition System: Description and Operation

System Schematic Diagram:

PURPOSE

Ignition system supplies sufficient spark to ignite air/fuel mixture.

OPERATION

The Powertrain Control Module (PCM) controls coil primary current through the coil primary circuit ground.

- When the primary circuit is grounded, current flowing in coil primary windings generates an electromagnetic field.

- When the primary circuit ground is removed, the field collapses, inducing high voltage (25,000-35,000 Volts), in the secondary windings.

This high voltage arcs between the spark plug electrodes, igniting the air/fuel mixture.

The PCM advances or retards ignition timing to provide the best compromise between power, fuel consumption, and emissions for all operating conditions.

COMPONENTS

System consists of the ignition coil, distributor, secondary ignition cables and spark plugs.