When the fuel gets low, the estimated range display goes away and just gives you the LOW warning. This happens when there is 1 to 2 gallons of gas left. Or in your case, 3.8 to 7.6 liters.
You can get back to the range display or any other display by selecting another display such as tire pressure then reselecting range display. The book I have doesn't specify exactly how much gas is left when it gives the LOW fuel warning or the expected range. A gallon should get you 35 or more miles. It would be nice if they were more specific.