Electronic Ignition

ECM computes correct timing of each ignition pulse in response to signals from engine speed (RPM) sensor, Camshaft Position (CMP) sensor, Mass Airflow (MAF) sensor, Engine Coolant Temperature (ECT) sensor, Throttle Position (TP) sensor, Knock Sensors (KS) and Transmission Control Module (TCM).

4-cylinder engines are equipped with two ignition coils, eliminating the distributor. ECM computes when each ignition coil must deliver its voltage pulse.