X Reg Renault Megan Outside Air Temperature display?

The outside air temperature display of my X reg Renault Megan has for some reason started to display totally inaccurate temperatures; 47degrees C, for example. Does any one know why this has happened and is it easy to repair. Could it be a comparatively simple thing like a bad or broken connection? If so, is it fairly easy to get to and replace or does it involve stripping things out?