MARELLI Electronic Ignition: Operation

Primary voltage is supplied to ignition coil by the battery, through the ignition switch. There are no resistors in the Marelli system. As distributor shaft rotates, the teeth of reluctor pass stator pole in the pick-up coil assembly. This creates and collapses a magnetic field, causing an electrical signal or impulse, which is sent to the control module. As signal is received, control module opens and closes ignition coil primary circuit. This causes a high voltage surge in the coil secondary windings, firing the spark plugs.