Ignition Control Module: Description and Operation

Igniter R&R:

The igniter (mounted in the distributor) receives signals from the pickup coil and triggers ignition coil secondary output. The pick-up coil generates a voltage signal when it's magnetic field changes as the reluctor (signal generator) passes. The low voltage signals are used by the Igniter unit to switch the ground circuit to the coil on and off, controlling firing time of the spark plugs.