Circuit Description

A direct ignition system (DIS) has been adopted. DIS improves ignition timing accuracy, reduces high-voltage loss and enhances overall reliability of ignition system by eliminating distributor. DIS is a 1-cylinder ignition system which ignites 1 cylinder with 1 ignition coil. In 1-cylinder ignition system, spark plug is connected to end of secondary winding. High voltage generated in secondary winding is applied directly to spark plug. Spark of spark plug passes through from center electrode to ground electrode.

The ECM determines ignition timing and outputs ignition signals (IGT) of each cylinder. Based on IGT signals, power transistors cut off current to primary coil in ignition coil. At same time, ignitor also sends an ignition confirmation signal (IGF) as a fail-safe measurement to ECM. Detecting condition of DTC is when there is no IGF signal to ECM while engine is running.