Ignition System: Description and Operation

The Electronic Ignition System consists of a distributor, Ignition Control Module (ICM), Electronic Control Unit (ECU), and Crankshaft Position Sensor (CPS). Proper spark advance is fully automatic, and is provided by a load table built into the ECU. The ECU also monitors signals from the Coolant Temperature Sensor (CTS), engine rpm, Manifold Air Temperature Sensor (MAT), and Manifold Absolute Pressure Sensor (MAP) when determining the correct ignition advance.