When Monitored:
WARNING: This page is about a different car, the 2012 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
There are two for this DTC. The first monitor runs at initial key on after an eight hours cold soak. The DEF Ambient Air Temperature Sensor is compared to the other temperature sensors. The second monitor runs after the engine is running. The PCM looks for a change in temperature over time.