Patent ID: 7991538

Claim:
A computer-readable medium containing a computer program which when executed by a processor performs a method for operating a fuel system of an internal combustion engine, in which a fuel quantity injected into a combustion chamber of an internal combustion engine is a function of an activation period using which a fuel injection device is activated, in which a pressure sensor detects a pressure in a fuel rail and provides a signal, and in which the pressure in the fuel rail is regulated to a setpoint pressure using a setting unit and employing the signal provided by the pressure sensor, the method comprising: (a) establishing a test fuel quantity to be injected; (b) operating the internal combustion engine using a first setpoint pressure and a first activation period corresponding thereto and to the test fuel quantity to be injected; (c) detecting a first value of a variable characterizing an operating state; (d) operating the internal combustion engine using a second setpoint pressure and a second activation period corresponding thereto and to the test fuel quantity to be injected; (e) detecting a second value of the variable characterizing the operating state; and (f) implementing an action if the detected first and second values of the variable differ by more than a limit value.