DISTRIBUTORLESS Ignition

NOTE: Coil-on-plug technology is used on 2.0L and 3.0L. ECM directly controls power transistor to control ignition timing.

Distributorless ignition system (DIS) is controlled by ECM. ECM determines operating condition of the engine based on signals from the pressure sensor, engine coolant temperature sensor, intake air temperature sensor, crankshaft position sensor and other sources. It then selects the ignition timing most appropriate for the condition thus determined from those stored in its memory and outputs at that timing a primary current "OFF" signal to the ignitor to initiate ignition. This control uses a quick-to-response learning feature by which the data stored in the ECM memory is processed in comparison with information from various sensors and switches. Thus, the ECM can always perform optimum ignition timing taking into account the output, fuel consumption, exhaust gas, and other factors for every engine operating condition. Engine speed fluctuates during start of the engine, so the ECM cannot control the ignition timing. During that period, the ignition timing is fixed at 10° BTDC by using the 10° signal from the crank- shaft position sensor.