Knock Sensor: Description and Operation

ESC Wiring Diagram:

The Electronic Spark Control (ESC) system is comprised of an ESC module, knock sensor and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ESC module, which sends 0 volts to the ECM. This signals the ECM to retard the timing, which eliminates detonation. As detonation is reduced, the ECM advances the timing again in small increments.