Engine Coolant Temperature Sensor (All Models)
WARNING: This page does not describe the selected car, but rather 17 other vehicles, including the 2003 Toyota Tundra, 2003 Toyota Tacoma, 2003 Toyota Sienna, 2003 Toyota Sequoia, and 2003 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
Engine Coolant Temperature (ECT) sensor contains a built-in thermistor in which resistance varies according to engine coolant temperature. ECT 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 (if equipped), EGR system (if equipped) and operation of electronically controlled transaxles/transmissions (if equipped). For ECT sensor location, see ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in appropriate REMOVAL, OVERHAUL & INSTALLATION article.