METHOD AND ARRANGEMENT FOR SENSOR DIAGNOSIS

摘要

The invention relates to a method for the diagnosis of a sensor in connection with control of a combustion engine. The method includes feeding fuel under pressure (p) to the engine, detecting the pressure (p) by means of the sensor, and controlling the air/fuel mixture based on to the operating state of the engine. The invention involves an intentional modification of both the pressure (p) and injection time period (tinj) during which fuel is fed to the engine. The modifications are selected in such a way that substantially no change in the fuel flow (F) to the engine is obtained. A check is performed to determine if the modifications of the pressure (p) and injection time period (tinj) result in any unallowable deviation in the operating state of the engine. If so, an indication that the sensor is defective is provided. With the invention, an improved diagnosis method for checking the functioning of a fuel pressure sensor is provided.