BOSCH Electronic Ignition System: Description
NOTE:
The Fiat Spider uses the Marelli Electronic Ignition System. The Porsche 924 uses a Bosch Hall Effect Electronic Ignition System. Other BMW, Porsche and Volvo models use computer-controlled systems. See appropriate articles in the Computerized Engine Control section.
The Bosch electronic ignition system consists of a control module, a breakerless distributor, a single or dual resistor, a high output ignition coil, an ignition switch, and battery.
Some models may use a resistor wire rather than resistors, while Mercedes-Benz models use no resistors. Standard centrifugal and vacuum advance/retard mechanisms are used. See Figure and Figure.
The distributor contains a rotating trigger wheel and a stationary magnetic pick-up coil (unless it is repositioned by vacuum diaphragm).