Ignition System: Description and Operation

The Electronic Ignition System consists of a distributor, Ignition Control Module (ICM), Electronic Control Unit (ECU), Crankshaft Position Sensor (CPS), engine knock sensor and a ignition relay. Proper spark advance is fully automatic, and is provided by a load table built into the ECU. When the knock sensor signals the ECU that pre-ignition is about to occur, the ECU will automatically retard ignition timing as required. When the threat of pre-ignition is eliminated as determined by engine load, the ECU will then slowly return ignition timing to its preset value.