Diagnostic method for a fuel pressure sensor in the common rail of an internal combustion engine

摘要

An internal combustion engine has a fuel pressure sensor, the measured value of which represents a fuel pressure in a fuel reservoir of the internal combustion engine. Fuel is metered from the fuel reservoir into a combustion chamber. In a predefined idle operating state (LBZ) of the internal combustion engine, a speed of the internal combustion engine is regulated so as to reach a specific idling speed. During the regulation process, a value of a manipulated variable for metering the fuel is determined, the value being required to reach the specific idling speed. Furthermore, it is concluded that the measured fuel pressure value contains an error (ERR) when the determined required value of the manipulated variable differs from a reference value (REF) predefined for the predefined idle operating state (LBZ) of the internal combustion engine by at least a given amount or factor.

主权项

1. A method for operating an internal combustion engine which comprises a fuel pressure sensor, the measurement value of which is representative of a fuel pressure in a fuel accumulator of the internal combustion engine from which fuel is metered into a combustion chamber of the internal combustion engine, the method, in a predefined idle operating state of the internal combustion engine, comprising:
regulating a rotational speed of the internal combustion engine to a predefined idle rotational speed and, during the course of said regulation, a value, which is required for attaining the predefined idle rotational speed, of an actuating variable for the metering of the fuel is determined, and inferring an error of the measurement value of the fuel pressure sensor if the determined required value of the actuating value deviates by at least a predefined magnitude or factor from a reference value predefined for the predefined idle operating state of the internal combustion engine.