I believe they used the fuel flow monitor that cars have anyway to just shut the fuel pump off after 7.1L when there is actually 9L of fuel in the tank. It's a

I believe they used the fuel flow monitor that cars have anyway to just shut the fuel pump off after 7.1L when there is actually 9L of fuel in the tank. It's a pressurized tank, so the extra fuel you can't reach takes way longer to go foul. Happily the software fix to remove the restriction is easy to find.