Patent ID: 8849547

Claim:
A method for testing a fuel quantity balance in a common rail system of an internal combustion engine having two electrically controllable actuating elements including a first controllable valve at the input side of a high-pressure fuel pump and a second controllable valve on the common rail, comprising: (a) setting a regulating mode by designating one of the two electrically controllable actuating elements as a controlled actuating element and designating the other electrically controllable actuating element as a regulated actuating element; (b) setting a defined operating state of the engine by specifying an engine rotational speed and a rail pressure; (c) setting a first system operating point by controlling the controlled actuating element; (d) measuring a first current value of one of the two electrically controllable actuating elements; (e) setting a second system operating point by controlling the controlled actuating element; (f) measuring a second current value of one of the two electrically controllable actuating elements; (g) forming a current value difference between the first and second current values; (h) performing a comparison between the current value difference and an assigned prespecified value; and (i) evaluating whether the fuel quantity balance shows an insufficient quantity, based on the result of the comparison.