Celica L4-96.8 1587cc 1.6L DOHC (4A-FE) (1990)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
Water Temperature Sensor (THW)
The Coolant Temperature Sensor, located on the top, rear of the engine, monitors coolant temperature with a thermistor whose resistance varies
according to engine temperature. The ECU uses this signal to control open/closed loop operation of the fuel injection system, overdrive on electronic
transaxles, spark advance (ESA), idle speed control system and EGR system. The THW inputs the ECU through terminal THW.