DISTRIBUTORLESS Ignition System (Q45)

Distributorless Ignition System (DIS) uses one ignition coil per cylinder. Individual coils are plugged directly onto spark plugs. No conventional distributor or high tension wires are used. An optical crankshaft angle sensor, used in place of distributor, monitors engine speed and piston location. See Figure . See CRANKSHAFT ANGLE SENSOR under INPUT DEVICES.

Signals created by crankshaft angle sensor are sent to Electronic Control Unit (ECU). ECU then delivers timing control signals to left and right power transistors. Power transistors, mounted on left and right valve covers, trigger appropriate ignition coil. Power for ignition coils is supplied from ignition switch through ignition coil relay.