Hyundai Elantra: Knock Sensor (KS). Description and Operation - Engine Control System - Engine Control/Fuel System - Hyundai Elantra HD 2006Ц2010 Service ManualHyundai Elantra: Knock Sensor (KS). Description and Operation

Function And Operation Principle

Knocking is a phenomenon characterized by undesirable vibration and noise and can cause engine damage. Knock Sensor (KS) senses engine knocking and the cylinder block. When knocking occurs, the vibration from the cylinder block is applied as pressure to the piezoelectric element. At this time, this sensor transfers the voltage signal higher than the specified value to the ECM and the ECM retards the ignition timing. If the knocking disappears after retarding the ignition timing, the ECM will advance the ignition timing. This sequential control can improve engine power, torque and fuel economy.