4 Runner 2WD L4-2693cc 27L DOHC MFI (1997) Knock Sensor Component Information Diagrams
Knock Sensor: Description and Operation
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which generates a voltage when
it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine knocking occurs, ignition timing is retarded to
suppress it.
If the ECM detects the above diagnosis conditions, it operates the fail safe function in which the corrective retard angle value is set to the
maximum value.
