Knock Sensor: Description and Operation

Electronic Spark Control (ESC):

ESC Module:

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