Distributor Ignition System (G20)

An optical crankshaft position sensor, mounted inside of distributor, monitors engine speed and piston location. See CRANKSHAFT POSITION SENSOR under INPUT DEVICES  . Signals created by crankshaft position sensor are sent to Engine Control Module (ECM). ECM then delivers ignition timing signals to power transistor. Power transistor triggers ignition coil. Power for ignition coil is supplied by ignition switch when switch is in START or RUN position.