Electronic Spark Control
Electronic Spark Control (ESC) system is a closed loop system that controls engine detonation by adjusting spark timing. This system consists of ignition system, ESC ignitor, detonation sensor, pressure sensor and control relay.
The detonation sensor detects presence (or absence) and intensity of detonation by vibration characteristics of engine. Detonation sensor sends electrical signal to ignitor. The ECU monitors signal and issues a command signal to ignitor to adjust ignition timing.
The distributor receives commands from controller, and spark timing is delayed during detonation, thus providing required retard. The amount of retard is a function of degree of detonation.