How do you change the climate control display on a peugeot 406 from Fahrenheit to Celsius?

To change the climate control display from Fahrenheit to Celsius on a Peugeot 406, locate the climate control unit on the dashboard. Press and hold the "Auto" button while simultaneously pressing the "Up" or "Down" temperature adjustment button until the display changes. Release both buttons, and the temperature unit should now be in Celsius. If this doesn't work, consult the owner's manual for specific instructions related to your model year.