Patent ID: 8245689

Claim:
A method for monitoring a control loop or a regulating loop in an engine system in a motor vehicle, the method comprising: identifying at least one state change occurring during ongoing operation of the motor vehicle by comparing, with an electronic processor, an absolute value of a gradient of a first parameter to determine if it exceeds a first threshold; identifying a steady operating state occurring during ongoing operation of the motor vehicle by comparing, with the electronic processor, an absolute value of a gradient of the first parameter to determine if it is at or below the first threshold; ascertaining, with the electronic processor, a characteristic value representing a measure of the performance of the control loop or regulating loop from a preset value and a resulting system variable only during the one or more state changes; and identifying an error as a function of the ascertained characteristic value exceeding an error threshold during the one or more state changes and outputting an indication that an engine system component is defective in response to the error; wherein the characteristic value is ascertained as a function of a triangle area of a triangle, a first corner point of the triangle being defined as the system variable at a first point in time, a second corner point of the triangle being defined as the preset value at the first point in time, and a third corner point being defined as the preset value at a second point in time at which the preset value has assumed a value of the system variable at the first point in time, and wherein the function of at least one of an air mass regulating system, an EGR rate regulating system, and a boost pressure regulating system in an engine system is monitored.