Knock Sensor: Description and Operation

Fig. 9 Knock sensor:

The knock sensor, Fig. 9, is an electronic device capable of measuring vibration and converting the vibration signal to an electrical output that measures the engine knock. The voltage signal generated by the knock sensor is sent to the knock control unit for filtering and then to the electronic control assembly for control of ignition timing. The sensor is threaded in the engine block near the oil pressure switch.