Ignition Control Module: Description and Operation

PURPOSE
The Igniter triggers the ignition coils, in the correct order, in response to the signals from the Engine Control Module (ECM). Computers generally produce low amperage signals as outputs, the igniter is essentially an electronic relay. It receives a "trigger" from the ECM and responds by sending a higher amperage current signal to the ignition coils.

OPERATION
The igniter temporarily interrupts the primary current with the ignition signal (IGF signal) from the ECM and generates sparks at the spark plug. Also, as a fail-safe measure, when ignition occurs an ignition confirmation signal (IGF signal) is sent to the ECM.