Camry XLE Sedan 4-Door L4-2164cc 2.2L DOHC MFI (1997)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
A thermistor built into the engine coolant temp. sensor changes the resistance value according to the engine coolant temp.
A thermistor built in the sensor changes the resistance value according to the engine coolant temp., The lower the engine coolant temp., the greater
the thermistor resistance value, and the higher the engine coolant temp., the lower the thermistor resistance value.
The engine coolant temp. sensor is connected to the ECM (See below). The 5V power source voltage in the ECM is applied to the engine coolant
temp. sensor from the terminal THW via a resistor R.
That is, the resistor R and the engine coolant temp. sensor are connected in series. When the resistance value of the engine coolant temp. sensor
changes in accordance with changes in the engine coolant temp., the potential at terminal THW also changes. Based on this signal, the ECM
increases the fuel injection volume to improve driveability during cold engine operation.
