gas consumption computer is not working.

What is your question?

Now the display can only show mileage. In the past I can select gas consumption status and how many mileage I can do under the current gas in tank. Now such information cannot be brought up, the display is only miles done so far no matter how many times I press the knob at the tip of the left stick under the steering wheel. Can I reset the computer to make it work again? or must I bring to repair shop?