Knock Sensor (KS) Description and Operation

Description

Knocking is a phenomenon characterized by undesirable vibration and noise that may cause engine damage. Two knock sensors (KS) are installed inside the V-bank of the cylinder block and detect engine knocking. When knocking occurs, the vibration of the cylinder block is transmitted to the piezoelectric element as pressure. When knocking is detected, the sensor outputs a voltage signal and the ECM retards the ignition timing. If the knocking disappears after retarding the ignition timing, the ECM advances the ignition timing again. This sequential control improves engine output, torque and fuel economy.