Evaporator Temperature Sensor: Operation

WARNING: This page is about a different car, the 2004 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.

The evaporator temperature sensor monitors the temperature of the A/C evaporator. The sensor will change its internal resistance in response to the temperatures it monitors. The A/C-heater control is connected to the sensor through a sensor ground circuit and a sensor signal circuit. As the evaporator temperature increases, the resistance of the sensor decreases and the voltage monitored by the A/C-heater control decreases. The A/C-heater control uses this monitored voltage reading to an indication of the evaporator temperature. The A/C-heater control is programmed to respond to this input by cycling the A/C compressor clutch as necessary to optimize A/C system performance and to protect the A/C system from evaporator freezing. The external location of the sensor allows the sensor to be removed or installed without disturbing the refrigerant in the A/C system.

The evaporator temperature sensor is diagnosed by performing the ATC Function Test using a DRBIII(R) scan tool. Refer to BODY DIAGNOSTIC PROCEDURES .

The evaporator temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.