Bad sensor or connection. When the brake duct falls out the sensor could be damaged from being dragged on the road. I'm not sure how to test it to see of its working right, someone else might know. Look for any damaged wires while you're at it.
Oh and only the 18-button computer is called the OBC (on board computer). The 7-button and 11-button models are called a MID (multi info display). :thumbup:
(Lower resistance means lower temperature. like how superconductors work.)The temp sensor circuit is open and the OBC is displaying the lowest possible reading because of that. As Engel stated check your driver side brake duct to see if it's still there and if it's gone see if the sensor is still there. When you have a sensor in place and the connections are good it should read close to the outside air temperature. To check the accuracy, mix a slush of water and ice in a styrofoam cup and immerse the tip of the temp sensor in it. The OBC display should read 32-33 degrees if its set for Fahrenheit, or 0 if the OBC is set for Celcius.