Method for coupling a control unit to a program for modeling an active chain diagnosis

A method for operating an engine control unit for controlling an engine system by coupling the engine control unit with an external computing unit performing an active chain diagnosis for an error analysis, the method comprising:

• within a scope of a first run, performing the following in sequence:
• specifying by the control unit a setpoint operating state of the system defined by a plurality of operating parameters of the system, affirmatively applying an error to the system, recording at least one of sensor values and actuating variables representing an actual operating state of the system, and computing by the active chain diagnosis a first intervention in the control unit using the at least one of the sensor values and the actuating variables recorded in the first run, wherein the first intervention includes at least one control signal for changing the actual operating state of the system;
• within a scope of a second run subsequent to the first run, performing the following in sequence:
• resetting the control unit and deleting an error memory in the control unit, respecifying by the control unit the setpoint operating state of the system specified in the first run, affirmatively applying the error from the first run to the system, carrying out the first intervention computed in the first run, recording at least one of sensor values and actuating variables representing an actual operating state of the system, and computing by the active chain diagnosis a second intervention in the control unit using the at least one of the sensor values and the actuating variables recorded in the second run, wherein the second intervention includes at least one control signal for changing the actual operating state of the system;
• and
• within a scope of at least one additional run subsequent to the second run, performing the following in sequence:
• resetting the control unit and deleting the error memory, respecifying by the control unit the setpoint operating state of the system specified in the first run, affirmatively applying the error from the first run to the system, carrying out the first and second interventions computed in the first and second runs, recording at least one of sensor values and actuating variables representing an actual operating state of the system, and computing by the active chain diagnosis at least one additional intervention in the control unit using the at least one of the sensor values and the actuating variables recorded in the at least one additional run, wherein the at least one additional intervention includes at least one control signal for changing the actual operating state of the system.