IGNITION SYSTEM

ELECTRONIC SPARK ADVANCE
Description

The ESA (Electronic Spark Advance) system is a system that uses the engine ECU to determine the ignition timing based on the signals from the various sensors.The engine ECU calculates the ignition timing from the optimum ignition timing stored in memory to match the engine conditions, and then sends the ignition signal to the igniter.The optimum ignition timing is basically determined using engine speed and intake air mass (manifold pressure).

The engine ECU (Electronic Control Unit) determines the ignition timing based on the G signal, NE signal and the signals from other various sensors.When the ignition timing has been determined, the engine ECU sends the IGT signal to the igniter.While the IGT signal sent to the igniter is ON, the primary current flows to the ignition coil. While the IGT signal turns off, the primary current to the ignition coil is shut off.At the same time, the IGF signal is sent to the engine ECU.Currently, the main ignition circuitry used is the DIS (Direct Ignition System).The engine ECU distributes the high-voltage current to the cylinders by sending each IGT signal to the igniters in the order of ignition.This makes it possible to provide highly accurate ignition timing control.