Highlander 2WD L4-2.4L (2AZ-FE) (2001)
Knock Sensor: Description and Operation
Knock Sensor
The knock sensor is filled to the cylinder block to detect the engine knocking. This sensor contains a piezoelectric element which generates a voltage
when it becomes deformed. This occurs when the cylinder block vibrates due to knocking. If the engine knocking occurs, the ignition timing is delayed
to suppress it.