1. A method for determining an operating characteristic of an injection system of an internal combustion engine, wherein the internal combustion engine includes a turbocharger, the method comprising the method steps: A) Performing a test injection of fuel into a cylinder of the internal combustion engine by means of the injection system; B) determining an operating parameter of the turbocharger; C) determining an operating characteristic of the injection system on the basis of the determined operating parameter of the turbocharger.