pretty sure the one behind the bumper defanitly controls the temp for the clocks. not sure weather its a different one for the climatronic. but my old car didnt have the climatronic and still had the temp sensor behind the bumper for the temp on the clocks.
dodgey sensor ide say, unless theres another one somewere, but ive not heard of another sensor, and cant see why they would have two to do the same job?