Estimating a Fuel Leakage Quantity of an Injection Valve During a Shut-Down Time of a Motor Vehicle

A method is disclosed for estimating a fuel leakage quantity which enters from a leaking injection valve during a shut-down time of a motor vehicle into an intake tract or into a cylinder of an internal combustion engine of the motor vehicle and is added to a fuel mixture to be combusted during a starting process. The method may include: measuring a first start index characteristic of a starting behavior of the engine during a first starting process; determining a first injected fuel quantity during the first starting process; measuring a second start index characteristic of a starting behavior of the engine during a second starting process; determining a second injected fuel quantity during the second starting process; and estimating the fuel leakage quantity based on the measured first start index, the determined first injected fuel quantity, the measured second start index and the determined second injected fuel quantity.