Fuel level display

Only 911 Carrera 4 (996) and GT3 are affected: 

If the power supply is interrupted due to a discharged or disconnected battery and a quantity of less than 19 liters remains in the tank, the calculated value for the range on remaining fuel will be deleted or falsified in the instrument cluster. If less than 10 liters of fuel remains in the tank, the fuel level warning light might not be activated. If the power supply is restored with the fuel level at less than 19 liters, it is possible that the fuel level display may subsequently display too much in some 996 Carrera 4 and GT3 vehicles.

This may lead to the vehicle breaking down. 

Remedy in these vehicles: 

Refill at least 19 liters of fuel. The fuel level sensor is then in operating range and its display precision is guaranteed.