Ignition Control Module: Description and Operation

Ignition Coil And Module Assembly:

Ignition Coil And Module:

The ignition coil/ignition control module assembly provides spark to the distributor assembly, timed by signals from the ECM. Power (B+) for the ignition coil primary circuit and the ignition control module is supplied by the ignition switch. The ECM combines the camshaft position information supplied by the distributor with other system parameters and calculates the required spark advance and coil dwell. The ECM signals the ignition control module, which turns on the primary current to the ignition coil by grounding the primary circuit, and then turns it off by removing the ground. When the primary current flow stops, high voltage induced in the ignition coil secondary winding becomes the spark voltage for the spark plug. The spark voltage is delivered to the distributor assembly through the coil output (secondary) wire, and then directed to the proper spark plug connector by the distributor rotor.