Knock Sensor: Description and Operation
Fig. 24 Knock control system component locations:
The knock control system, Fig. 24, is used to detect a knock or a ping in the engine. Using a sensor (piezo-electric crystal) to sense vibration it then sends a signal to the control unit. Once detecting a knock it will retard ignition timing in small increments until knocking stops. After knocking has ceased it returns timing to specification.