Genuine OEM Volvo Engine Knock Sensor, part number 30757381. This sensor detects engine knocking or pre-ignition, allowing the engine control unit to adjust ignition timing for optimal performance and to prevent potential engine damage. It is a critical component for engine health and efficiency. The part has a length of 0.22733 meters. Genuine OEM knock sensors are calibrated to precisely detect specific vibration frequencies associated with knocking, ensuring accurate engine management.