It is more likely you need to replace the sensor, NOT the display. This is about a one hour job you can do yourself. You can buy the part from Mercedesshop for about $50 or (if you are feeling a little more adventurous) you can buy a sensor without the connector from Radio Shack or other places and solder the new one on in place of the old one. Do a search for more info using a term like exterior temperature gauge or outside temperature gauge

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Chip Johnson