MARELLI Electronic Ignition System: Operation

Primary voltage is supplied to the ignition coil by the battery, through the ignition switch. There are no resistors in the Marelli system. As the distributor shaft rotates, the teeth of the trigger approach and then pass the stator pole in the pick-up coil assembly.

This creates and collapses a magnetic field, causing an electrical signal or impulse, which is fed to the control module. As this signal is received, the control module opens and closes the ignition coil primary circuit. This causes a high voltage surge in the coil secondary windings, firing the spark plugs.