Ignition Timing Control: Notes

A microcomputer in the PCM controls the ignition timing according to engine speed and vacuum pressure in the intake manifold. Engine speed and vacuum pressure are transmitted to PCM by signals from crank sensor, cylinder (CYL) sensor, TDC sensor (Integra and Vigor), throttle position sensor, coolant temperature sensor, knock sensor(s), and MAP sensor.

The PCM contains memory for ignition timing at various engine speeds, manifold pressure and coolant temperature. When these conditions have been processed, PCM sends signals to ignitor unit to control ignition timing.