Theory Of Operation
The HVAC Module uses a variety of sensors to adjust HVAC operation to obtain optimal performance. These sensors are continuously monitored by the HVAC Module to assure that they are in range. An active Diagnostic trouble Code (DTC) indicates that a sensor is out of range. A stored DTC indicates that the sensor was out of range but is currently within range.
The HVAC Module maintains the interior comfort level desired by the vehicle operator. This is accomplished by use of two air duct temperature sensors, located in the HVAC housing, that measure the temperature of the conditioned air leaving the HVAC housing and an infrared in-car temperature sensor, located behind the rear view mirror, that measures the temperature of the conditioned air within the vehicle.