Abstract: An engine exhaust sensor diagnostic system for an exhaust system including a catalyst and a post-catalyst oxygen sensor includes a first module that calculates a total integrated area based on a signal generated by the post-catalyst oxygen sensor. A second module compares the total integrated area to a threshold integrated area and generates a pass status signal when the total integrated area is less than the threshold integrated area.

Abstract: An engine exhaust sensor diagnostic system for an exhaust system including a catalyst and a post-catalyst oxygen sensor includes a first module that calculates a total integrated area based on a signal generated by the post-catalyst oxygen sensor. A second module compares the total integrated area to a threshold integrated area and generates a pass status signal when the total integrated area is less than the threshold integrated area.

Abstract: A method and system to optimize values of a plurality of calibration discharge coefficients useable in a computer program operable to estimate mass air flow into an internal combustion engine having an air intake system comprising a throttle body and a plurality of sensors is presented. This includes collecting engine operation data points, including throttle position. Discharge coefficients are calculated, one for each engine operation data point. The discharge coefficients are partitioned based upon throttle position. Calibration discharge coefficients are calculated for each partitioned plurality of discharge coefficients. This includes circumscribing each calibration discharge coefficient based upon predetermined thresholds. This further includes monitoring and collecting input signals correlatable to airflow from the sensors during ongoing engine operation, preferably comprising throttle position, manifold pressure, intake air temperature, and, atmospheric pressure.

Abstract: An engine exhaust sensor diagnostic system includes an oxygen sensor and a controller. The controller monitors a signal generated by the oxygen sensor, determines a rate of change of the signal, and computes diagnostic parameters. The controller indicates malfunction of the oxygen sensor if the diagnostic parameters are smaller in magnitude than corresponding thresholds.

Abstract: A process for computer based, wholly passive, diagnosis of an automotive vehicle exhaust gas recirculation system is disclosed. Use is made of any suitable math model of the vehicle's air intake system to estimate the absolute pressure in the intake manifold, MAP, assuming both a healthy EGR system, MAPHE, and a faulty EGR valve, MAPFE. Both estimated values are compared with the actual normally measured manifold pressure, MAPmeas. Both comparisons are repeated over many calculations and the differences analyzed to reliably determine whether there is a real restriction to recirculated exhaust flow. A preferred math model of the intake system uses as input variables: mass air flow, barometric pressure, the position command for the EGR valve and engine speed.

Abstract: A fault identification system for intake system sensors according to the invention includes a throttle position sensor (TPS), a manifold absolute pressure (MAP) sensor, and a mass airflow (MAF) sensor. A diagnostic controller is coupled to the TPS, the MAP sensor and the MAF sensor. The diagnostic controller implements a throttle model, a first intake model and a second intake model and correctly identifies faults in the TPS, the MAP sensor and the MAF sensor. The throttle model generates a mass airflow estimate. The first intake model generates a first MAP estimate. The second intake model generates a second MAP estimate. The diagnostic controller applies residual calculations on outputs of the throttle model, the first intake model and the second intake model. The diagnostic controller applies a first order lag filter on the residual calculations. The diagnostic controller accesses a truth table to identify faults in the TPS, the MAP sensor and the MAF sensor.

Abstract: A fault identification system for intake system sensors according to the invention includes a throttle position sensor (TPS), a manifold absolute pressure (MAP) sensor, and a mass airflow (MAF) sensor. A diagnostic controller is coupled to the TPS, the MAP sensor and the MAF sensor. The diagnostic controller implements a throttle model, a first intake model and a second intake model and correctly identifies faults in the TPS, the MAP sensor and the MAF sensor. The throttle model generates a mass airflow estimate. The first intake model generates a first MAP estimate. The second intake model generates a second MAP estimate. The diagnostic controller applies residual calculations on outputs of the throttle model, the first intake model and the second intake model. The diagnostic controller applies a first order lag filter on the residual calculations. The diagnostic controller accesses a truth table to identify faults in the TPS, the MAP sensor and the MAF sensor.

Abstract: A process for computer based, wholly passive, diagnosis of an automotive vehicle exhaust gas recirculation system is disclosed. Use is made of any suitable math model of the vehicle's air intake system to estimate the absolute pressure in the intake manifold, MAP, assuming both a healthy EGR system, MAPHE, and a faulty EGR valve, MAPFE. Both estimated values are compared with the actual normally measured manifold pressure, MAPmeas. Both comparisons are repeated over many calculations and the differences analyzed to reliably determine whether there is a real restriction to recirculated exhaust flow. A preferred math model of the intake system uses as input variables: mass air flow, barometric pressure, the position command for the EGR valve and engine speed.

Abstract: A method is disclosed for computer-based control of the timing and level of gear shifts in a multi-speed automatic transmission operated in combination with an internal combustion engine and interposed fluid torque converter. The computer containing power control module signals gear shifts in response to its repeated cyclic processing of engine and transmission operation parameters including torque converter slippage. Here, such slippage is estimated using a neural network with suitable such parameters as input data. In preferred modes of operation, different neural networks are available for selection and use by the computer in different modes of engine-transmission operation.