Knock Sensor
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 Lexus SC 430, 2002 Lexus RX 300, 2002 Lexus LX 470, 2002 Lexus LS 430, and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
A piezoelectric ceramic element is incorporated within each knock sensor. If engine knocking occurs because of detonation, piezoelectric element vibrates, generating voltage. Based on this voltage signal, Engine Control Module (ECM) retards ignition timing. All models are equipped with 2 knock sensors. For knock sensor location, see REMOVAL, OVERHAUL & INSTALLATION article.