Discharge Air Temperature Sensor / Switch: Description and Operation
EVAPORATOR DISCHARGE AIR TEMPERATURE SENSORThe evaporator discharge air temperature sensor contains a thermistor which receives a reference voltage from the PCM. The thermistor then varies the resistance to the reference voltage based on the evaporator discharge air temperature. The resulting voltage is returned to the PCM where it is interpreted as an evaporator air discharge temperature reading.
The PCM maintains evaporator core temperature and prevents icing of the evaporator core, by disengaging the A/C compressor clutch when the evaporator discharge air temperature sensor reading falls below acceptable levels, and by engaging the A/C compressor clutch when the discharge air temperature rises above acceptable levels.
The evaporator discharge air temperature sensor is located inside of the heater core and evaporator core housing in the air-stream leaving the evaporator core.