Knock Sensor

Knock sensors are installed on the left and right banks of the cylinder block (LS400) or on cylinder block (ES250). A piezoelectric ceramic element is incorporated into 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 ECU. ECU uses this signal to retard ignition timing to prevent knocking.