4 Runner 2WD L4-144.4 2366cc 2.4L SOHC (22R-E) (1990)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
Water Temperature Sensor (THW)
The Coolant Temperature Sensor, located on 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.