Evaporator Temperature Sensor

Evaporator Temperature Sensor

The evaporator temperature sensor is a NTC (negative temperature coefficient) thermistor that provides the ATC (automatic temperature control) module with a temperature signal from the air outlet side of the evaporator. The evaporator temperature sensor is installed in the RH side of the heater assembly casing, and extends into the core of the evaporator.

The ATC (automatic temperature control) module uses the input from the evaporator temperature sensor to control the engagement and disengagement of the A/C (air conditioning) compressor clutch, to prevent the formation of ice on the evaporator.

The signal voltage from the evaporator temperature sensor is between 0 and 5 V. The ATC (automatic temperature control) module monitors the signal voltage and defaults to a temperature of 0 degree C (32 degrees F) if it goes out of the range 0.157 - 4.784 V:

The signal voltage from the evaporator temperature sensor is between 0 and 5 V. The ATC (automatic temperature control) module monitors the signal voltage and defaults to a temperature of 0 degree C (32 degrees F) if it goes out of the range 0.157 - 4.784 V:
^ If the signal voltage is less than 0.157 V, the ATC (automatic temperature control) module assumes there is a short circuit to ground.
^ If the signal voltage is more than 4.784 V, the ATC (automatic temperature control) module assumes there is an open circuit or a short circuit to battery.