Town & Country V6-3.8L (2009)
Evaporator Temperature Sensor / Switch: Description and Operation
Front Evaporator Temperature Sensor - Operation
OPERATION
The evaporator temperature sensor monitors the surface temperature of A/C evaporator and supplies an input signal to the A/C-heater control. The
A/C-heater control uses the evaporator temperature sensor input signal to optimize A/C system performance and to protect the A/C system from
evaporator freezing. 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 circuit and a 5-volt reference signal circuit. As the temperature of the A/C evaporator decreases, the
internal resistance of the evaporator temperature sensor decreases.
The A/C-heater control uses the monitored voltage reading as an indication of evaporator temperature. The A/C-heater control is programmed to respond
to this input by requesting the Powertrain Control Module (PCM) or the Engine Control Module (ECM) (depending on engine application) to cycle the
A/C compressor as necessary to optimize A/C system performance and to protect the A/C system from evaporator freezing See: Heating and Air
Conditioning/Compressor HVAC/Description and Operation/A/C Compressor - Operation.
The evaporator temperature sensor is diagnosed using a scan tool See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures.
The evaporator temperature sensor cannot be adjusted or repaired and it must be replaced if inoperative or damaged.
