Abstract: A method for accurately diagnosing deterioration in an emission control system for a lean burn internal combustion engine is presented. The emission control system includes an Active Lean NOx (ALNC) Catalyst and a system for injecting a hydrocarbon-based reductant into the ALNC thereby improving its NOx conversion efficiency. The method teaches calculating a rate of change of exotherm across the ALNC and differentiating between deterioration of the ALNC and deterioration of the reductant injection system based on the magnitude and the sign of the rate of change of the exotherm. Once the diagnosis of deterioration is made, and the deteriorated component is identified, appropriate corrective measures, such as adjusting or discontinuing the reductant injection amount, and setting diagnostic codes, are taken.

Abstract: An electronic engine controller limits the maximum temperature of a midbed point within a catalytic converter by determining an instantaneous temperature of the midbed point as a function of a temperature of exhaust gas at an exhaust flange, of a temperature variation of exhaust gas from the exhaust flange and exhaust gas inlet to the catalytic converter, of exhaust gas at an exhaust gas inlet to the catalytic converter, and as a function of a predetermined value indicative of a temperature rise of exhaust gas in the catalytic converter. The temperature is compared to a maximum midbed temperature range and a first air/fuel modulation variable is altered by a predetermined amount if the temperature of the midbed point is within the maximum midbed temperature range and the first air/fuel modulation variable is set to a predetermined value if the midbed temperature is below the maximum midbed temperature range.

Abstract: A control system for an automatic transmission for an automative vehicle having a torque converter and a combustion engine including a microprocessor that is adapted to establish optimum control pressure levels for fluid pressure operated clutch and brake servos that effect gear ratio changes wherein provision is made for adjusting system pressures to maintain ratio shift quality in accordance with variations in a plurality of control sensor inputs including vehicle deceleration during ratio shifting and changes in the rate of change of converter turbine speed wherein optimum servo pressures are maintained following a ratio shift and during a ratio shift as torque capacity of one servo is reduced in synchronism with a torque capacity increase for a companion servo.