Knock Sensor

ES300 is equipped with one knock sensor. All other models are equipped with 2 knock sensors. A piezoelectric ceramic element is incorporated within the sensor.

If knocking develops in the engine, this piezoelectric element, by resonating with the knocking vibration, generates a voltage which corresponds with the knocking strength and sends a signal to the ECM. ECM uses this signal to retard ignition timing to prevent knocking.