I think it is really two small LCD panels, or something like that. When working, its supposed to tell you the temperature - in USA cars it will be degrees F. If yours is like mine, the right-hand digit is unreadable, like an LCD gone bad. So I can tell what the temperature is in tens of degrees F. (It should display two digits and a +/- sign.)
When you find out the price to fix it is something like $450, you might decide just to live with it like I did.
Maybe someday if I see a cheap instrument cluster on EBay - maybe........
Also, when you are sitting still in traffic the temperature will creep up because the sensor is getting heated by the engine.