Pacifica V6-3.8L VIN L (2005)
Ambient Temperature Sensor / Switch HVAC: Description and Operation
Infrared Temperature Sensor
The infrared temperature sensor consists of two infrared transducers that are concealed behind a clear lens located within the instrument panel mounted
A/C-heater control. These sensors are used only on models equipped with the automatic temperature control (ATC) heating-A/C system.
The dual infrared temperature sensors provide independent measurement inputs to the automatic temperature control (ATC) A/C-heater control module
that indicates the surface temperature of the driver seat and front seat passenger seat occupants. By using a surface temperature measurement, rather than
an air temperature measurement, the ATC system is able to adjust itself to the comfort level as perceived by the occupant. This allows the system to
detect and compensate for other ambient conditions affecting comfort levels, such as solar heat gain or evaporative heat loss. The ATC system logic
responds to the infrared sensor inputs by calculating and adjusting the air flow temperature and air flow rate needed to properly obtain and maintain the
individually selected comfort level temperatures of both the driver and passenger seat occupants.
The ATC A/C-heater control module continually monitors the infrared sensor circuits, and will store a diagnostic trouble code (DTC) for any problem it
detects. The infrared temperature sensor is diagnosed using a DRBIII(R) scan tool.
The infrared sensors cannot be adjusted or repaired and, if faulty or damaged, the A/C-heater control must be replaced.