Hyundai Elantra HD: 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.
