Knock Sensor

Knock sensors are piezoelectric devices that detect engine knocking or detonation caused by abnormal combustion. Typically mounted on the cylinder block or intake manifold, these sensors monitor high-frequency pressure pulsations indicative of premature ignition. Detected signals are relayed to the engine control unit (ECU) which retards ignition timing to protect against engine damage. Modern knock sensors utilize robust ceramic elements and shielding to withstand high temperatures and vibration. Variations exist for number of conductors and physical thread size, dictating vehicle-specific applications.