Grand Caravan V6-3.8L VIN L (2007)
Evaporator Temperature Sensor / Switch: Description and Operation
Operation - Front
OPERATION
The evaporator temperature sensor monitors the temperature of the refrigerant leaving the A/C evaporator or the conditioned air once it passes through
the A/C evaporator (depending on model application). The evaporator temperature sensor will change its internal resistance in response to the
temperatures it monitors and is connected to the A/C-heater control through sensor ground and signal circuits. As the refrigerant or conditioned air
temperature increases, the resistance of the evaporator temperature sensor decreases and the voltage monitored by the A/C-heater control decreases.
The A/C-heater control uses this monitored voltage reading as an indication of the evaporator temperature. The A/C-heater control is programmed to
respond to this input by sending electronic messages to the powertrain control module (PCM) over the controller area network (CAN) data bus. The
PCM then cycles 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 locations of the evaporator temperature sensor on all models allows the sensor to be removed or installed without disturbing the refrigerant
in the A/C system.
The evaporator temperature sensor is diagnosed using the DRBIII(R) scan tool.
The evaporator temperature sensor cannot be adjusted or repaired and must be replaced if found inoperative or damaged.
