Abstract: A computer controller is described for disabling fuel injection into cylinder groups of an engine. The system controls engine output a reduced engine torques without reducing engine air amounts below an engine misfire amount by reducing the number of cylinders carrying out combustion. Engine airflow is controlled to maintain accurate torque at requested levels throughout engine operating ranges.

Abstract: A valve control and diagnostic system uses physical stops to determine whether a connection between the valve motor and the valves has become degraded. The method can detect degradation in both the opening and closing direction, as well as in multi-valve systems, such as used on internal combustion engines.

Abstract: A method for controlling an engine coupled to a transmission is described. The method is especially suited for a transmission having at least one gear in which an over-running clutch is present. The invention describes a method for adjusting an engine operating parameter to maintain transmission input speed at or below a synchronous transmission input speed when the transmission is in the gear with the over-running clutch. The synchronous transmission input speed is based on transmission state and transmission output speed. Alternatively, vehicle speed can be used in place of transmission output speed.

Abstract: A method for controlling cycling of an air conditioning compressor coupled to an internal combustion engine interrupts normal cycling based on operation conditions. In addition, normal engaged and disengaged cycling durations are adaptively estimated in real-time. The method of the present invention achieves improved fuel economy and improved drive feel. As an example, improved fuel economy is achieved by engaging the compressor during braking or when the engine is being driven by the vehicle. As another example, improved drive feel is achieved by engaging the compressor during transient conditions when drive feel is unaffected.

Abstract: A computer controller is described for disabling fuel injection into cylinder groups of an engine. The system controls engine output a reduced engine torques without reducing engine air amounts below an engine misfire amount by reducing the number of cylinders carrying out combustion. Engine airflow is controlled to maintain accurate torque at requested levels throughout engine operating ranges.

Abstract: A diagnostic method for a motor vehicle having an internal combustion engine operable in a plurality of compression ratio operating states includes the steps of determining a change in idle air flow of the engine as the engine is operated in selected ones of the compression ratio operating states, and evaluating operation of the internal combustion engine based at least in part on the change in idle air flow.

Abstract: A method for estimating operating parameters of an internal combustion engine uses data stored as a function of intake and exhaust valve timing. In particular, the parameters are stored at a default operating point, several stability limited points, a high performance point, and an intermediate point. An inverse distance interpolation algorithm is used to calculated current slope and offset values at the current operating conditions. From these calculated slope and offset values, engine operating parameters, such as manifold pressure and cylinder air amount, are estimated.

Abstract: A method for operating a variable compression ratio internal combustion engine includes the steps of determining a compression ratio operating state of the engine and inferring the air pressure within the engine's intake manifold, based at least in part on the compression ratio operating state of the engine.

Abstract: A system and method wherein a torque monitoring algorithm compares torque demand (i.e., driver-demanded torque computed primarily from acceleration pedal position), with two independent torque estimates (e.g., one estimated from throttle position and one estimated from mass airflow (MAF) to the intake manifold). If the maximum of the two actual torque estimates exceeds the driver-demanded torque, the monitoring algorithm logic intervenes in engine torque production (e.g., shuts off fuel to cylinders) and lights a service (wrench) light. In order to prevent, or minimize, unnecessary engine torque production intervention, reducing a torque demand signal to the throttle by a factor, such factor being a function of airflow meter load divided by throttle load. If the air-meter reads higher than the throttle based estimate of air and torque, then the method simply closes the throttle until the air-meter is satisfied.

Abstract: A system and method wherein a torque monitoring algorithm compares torque demand (i.e., driver-demanded torque computed primarily from acceleration pedal position), with two independent torque estimates (e.g., one estimated from throttle position and one estimated from mass airflow (MAF) to the intake manifold). If the maximum of the two actual torque estimates exceeds the driver-demanded torque, the monitoring algorithm logic intervenes in engine torque production (e.g., shuts off fuel to cylinders) and lights a service (wrench) light. In order to prevent, or minimize, unnecessary engine torque production intervention, reducing a torque demand signal to the throttle by a factor, such factor being a function of airflow meter load divided by throttle load.

Abstract: A method and apparatus for operating a lean-burn internal combustion engine in cooperation with an exhaust gas purification system having a three-way catalyst and a NOx trap located downstream of the three-way catalyst includes a controller which calculates current levels of tailpipe NOx during lean engine operating conditions based upon the difference between a determined instantaneous feedgas NOx concentration and a determined instantaneous trap efficiency. The controller discontinues lean engine operation when the tailpipe NOx, expressed in terms of either grams-per-mile or grams-per-hour, exceeds a predetermined threshold level, either instantaneously or as averaged over the course of a trap purge-fill cycle.

Abstract: A method of operating a variable compression internal combustion engine in a motor vehicle includes the steps of determining a driveline surge based at least in part on operating parameters of the motor vehicle, determining a driveline surge tolerance based at least in part on one or more of the vehicle operating parameters, and selecting one of the compression ratio operating modes based at least in part on a comparison of the driveline surge to the driveline surge tolerance. With a variable compression engine operating in a high compression ratio mode or a low compression ratio mode, the low compression ratio mode is selected if the driveline surge exceeds the driveline surge tolerance. Otherwise, if the driveline surge is less than or equal to the driveline surge, then the high compression ratio mode is selected.

Abstract: A method for estimating operating parameters of an internal combustion engine uses data stored as a function of intake and exhaust valve timing. In particular, the parameters are stored at a default operating point, several stability limited points, a high performance point, and an intermediate point. An inverse distance interpolation algorithm is used to calculated current slope and offset values at the current operating conditions. From these calculated slope and offset values, engine operating parameters, such as manifold pressure and cylinder air amount, are estimated.

Abstract: A method for operating a variable compression ratio internal combustion engine includes the steps of determining a compression ratio operating state of the engine and inferring an exhaust temperature for the engine based at least in part on the compression ratio operating state of the engine.

Abstract: A method for operating a variable compression ratio internal combustion engine includes the steps of determining a compression ratio operating state of the engine and inferring the air pressure within the engine's intake manifold, based at least in part on the compression ratio operating state of the engine.

Abstract: A diagnostic method for a motor vehicle having an internal combustion engine operable in a plurality of compression ratio operating states includes the steps of determining a change in spark adjustment required to avoid knock as the engine is operated in selected ones of the compression ratio operating states, and evaluating operation of the internal combustion engine based at least in part on the change in spark adjustment.

Abstract: A method for controlling cycling of an air conditioning compressor coupled to an internal combustion engine interrupts normal cycling based on operation conditions. In addition, normal engaged and disengaged cycling durations are adaptively estimated in real-time. The method of the present invention achieves improved fuel economy and improved drive feel. As an example, improved fuel economy is achieved by engaging the compressor during braking or when the engine is being driven by the vehicle. As another example, improved drive feel is achieved by engaging the compressor during transient conditions when drive feel is unaffected.

Abstract: A method for controlling a powertrain of a vehicle is described. The method determines a desired vehicle condition based on three driver actuated elements. In a preferred embodiment the first element can be pedal position, the second element can be a brake actuator or, more specifically, brake actuation duration, and the third element can be a gear selection lever. Further, the desired vehicle condition can be desired powertrain output, vehicle acceleration, or various other parameters.

Abstract: A method and apparatus for controlling the operation of a “lean-burn” internal combustion engine in cooperation with an exhaust gas purification system having an emissions control device capable of alternatively storing and releasing NOx when exposed to exhaust gases that are lean and rich of stoichiometry, respectively, optimizes vehicle fuel economy while complying with emissions standards by prohibiting lean engine operation only when tailpipe emissions, calculated in terms of grams of an exhaust gas constituent per vehicle mile traveled, exceeds a permissible threshold value. The threshold value is preferably itself periodically determined based upon a detected or determined level of vehicle activity, such that vehicle activity characterized by greater transient engine operation prescribes a relatively lower level of permissible vehicle emissions.

Abstract: A method and apparatus for operating a lean-burn internal combustion engine in cooperation with an exhaust gas purification system having a three-way catalyst and a NOx trap located downstream of the three-way catalyst includes a controller which calculates current levels of tailpipe NOx during lean engine operating conditions based upon the difference between a determined instantaneous feedgas NOx concentration and a determined instantaneous trap efficiency. The controller discontinues lean engine operation when the tailpipe NOx, expressed in terms of either grams-per-mile or grams-per-hour, exceeds a predetermined threshold level, either instantaneously or as averaged over the course of a trap purge-fill cycle.