Ignition Timing Control: Notes

PCM controls ignition timing according to signals transmitted to PCM by Crankshaft Position (CKP) sensor, Cylinder Position (CYP) sensor, TDC sensor, Throttle Position (TP) sensor, Engine Coolant Temperature (ECT) sensor, Knock Sensors (KS), and Manifold Absolute Pressure (MAP) sensor.

PCM calculates ignition timing for each engine speed, manifold pressure, and coolant temperature. When these conditions have been processed, PCM sends signals to Ignition Control Module (ICM) to trigger coil(s).