Abstract: A method of conducting prognosis for an airflow management system for a combustion engine includes adjusting a throttle body valve position control signal in response to a detected airflow variation and monitoring an airflow variation compensation (AVC) value corresponding to a degree of adjustment of the control signal. The method also includes generating a throttle body coking severity metric based on at least a plurality of residual error values and the AVC value, and executing at least one response action based on the throttle body coking severity metric exceeding a predetermined threshold.

Abstract: A system and method for misfire detection in a multi-cylinder internal combustion engine system includes an engine-speed activated artificial neural network (ANN)-based detection function. An input vector includes a plurality of engine speed derivatives attributable to a respective cylinder, and also includes engine speed and load values. The input vector values are updated each combustion cycle. A conventional misfire detection block is used when the engine speed is at or below an engine speed threshold. An ANN-based misfire detection block is used when the engine speed exceeds the threshold. The ANN-based block is configured to emulate a plurality of distinct ANNs each of which is conditioned by a respective set of weights and biases to correspond to and detect when a respective cylinder has misfired. The ANN-based block includes an output signal for each ANN indicating whether the respective cylinder has misfired.