Engine Coolant Temperature (ECT) 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.
ECT sensor contains a built-in thermistor in which resistance varies according to engine coolant temperature. ECT sensor delivers an input signal to THW terminal of Engine Control Module (ECM). ECM may use input signal for determining ignition timing (spark advance) and for controlling fuel injection system, engine idle speed control system, heated oxygen sensor system and operation of electronically controlled transaxles/transmissions. For ECT sensor location, see ENGINE SENSORS & SWITCHES in appropriate SYSTEM & COMPONENT TESTING article.