Ignition System - Solid State: Operation

The electronic control module and ignition coil are on whenever ignition switch is in the "START" or "RUN" position. As each tooth of trigger wheel passes the pick-up coil, it interrupts the magnetic field around pick-up coil. This continual build-up and collapse of magnetic field provides a signal to MCU.

The MCU receives pick-up coil signals, along with other engine sensor signals, and sends a spark timing signal to ECM. The ECM then turns off current flow to ignition coil primary circuit.

The collapse of magnetic field in coil primary circuit induces a high voltage surge in secondary circuit. This causes current to flow from coil to distributor, rotor, cap and spark plug wires.