How do you get the mileage left display on your citreon xsara Picasso?

To display the mileage left on your Citroën Xsara Picasso, turn on the ignition without starting the engine. Then, press the trip computer button on the stalk or the dashboard, which is often labeled with a "Trip" or "Reset" symbol. This should cycle through the available displays, including the remaining mileage based on the fuel left in the tank. If this doesn't work, consult the vehicle's owner manual for specific instructions tailored to your model year.