Ignition Control Module: Description and Operation

The igniter unit is located inside the distributor. The igniter is used as a control device for the ignition coil. It is powered by ignition switch terminal Ign. 1 and receives power anytime the switch is turned ON. Based on the information provided by the TDC and CRANK sensors, the ECU pulses pins B15 and B17. Each time the igniter is pulsed, the ignition coil is signaled to send a spark to a spark plug. By modifying the pulse supplied to the igniter the ECU is able to retard or advance ignition timing as conditions require.