Theory Of Operation

WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.

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 Duct temperature sensors monitor the air temperature of the A/C air distribution duct work and supplies an input signal to the HVAC Module. The input signal value is used to optimize the A/C system performance. The Duct temperature sensor resistance value will change in response to the air temperature output of the air distribution duct work. The resistance value is electronically transferred to the HVAC Module using a sensor ground circuit and a 5-volt reference signal circuit. Normal operation of the sensor: the resistive value decreases when the duct work air temperature decreases and the sensor resistive value increases when the duct work air temperature increases.