Abstract: A system (10) for controllably disabling cylinders in an internal combustion engine (12) includes a throttle (18) controlling air flow to an intake manifold (14), a number of cylinder deactivation devices (1001-100K) and an engine controller (28) controlling fueling (90), ignition timing (94) and throttle position (86). The controller (28) is operable to activate only the minimum number of cylinders required to achieve a desired engine/vehicle operating parameter value, open the throttle (18) to a computed throttle position, control ignition timing sufficiently to drive the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value, and to then control the flow area of the throttle (18) while also controlling ignition timing to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value. The engine/vehicle operating parameter may be engine output torque, engine speed or vehicle speed.

Abstract: A system (10) for controllably disabling cylinders in an internal combustion engine (12) includes a throttle (18) controlling air flow to an intake manifold (14), a number of cylinder deactivation devices (1001-100K) and an engine controller (28) controlling fueling (90), ignition timing (94) and throttle position (86). The controller (28) is operable to activate only the minimum number of cylinders required to achieve a desired engine/vehicle operating parameter value, open the throttle (18) to a computed throttle position, control ignition timing sufficiently to drive the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value, and to then control the flow area of the throttle (18) while also controlling ignition timing to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value. The engine/vehicle operating parameter may be engine output torque, engine speed or vehicle speed.

Abstract: An exhaust gas re-circulation (EGR) system is provided for use in conjunction with an internal combustion engine. The EGR system includes an intake manifold, an exhaust manifold, a passageway connected in flow communication between the exhaust manifold and the intake manifold, and an EGR valve interposed in the passageway for controlling re-circulation of exhaust gas into the intake manifold. In addition, an emissions control device (e.g., a catalytic converter) for reducing exhaust emissions in the gas flowing into the intake manifold is connected in flow communication with the EGR valve.

Abstract: An improved engine torque management control that coordinates engine throttle, spark and EGR under predefined highly throttled conditions so as to maximize the fuel economy improvement of EGR without degrading engine performance. Under the predefined conditions, EGR is increased to a level that maximizes the fuel economy improvement without causing combustion instability, and the throttle position and spark timing are controlled to compensate for the anticipated torque loss while increasing volumetric efficiency and reducing pumping losses. During idle and steady state cruising operation, EGR is increased, and engine throttle position is controlled to regulate the estimated engine output torque in accordance with the driver requested output torque. During transient torque increases, throttle control alone is used to regulate the output torque, while in transient torque decreases, the throttle position is maintained and spark timing is used to regulate the output torque.

Abstract: Internal combustion engine air/fuel ratio control responsive to low voltage operating conditions of an electrical system maintains stable, precise air/fuel ratio conditions under electrical system fault conditions affecting operation of fuel control components including fuel pumps, fuel injectors, and drivers therefor. Electrical system operating voltage is monitored and when a voltage drop below a voltage threshold associated with reliable engine cylinder air/fuel ratio control is diagnosed, the air/fuel ratio smoothly transitions to a reduced engine performance operating mode which, at least for high engine output power requests, limits fueling and airflow to the engine cylinders to a level that may be accurately, reliably supported by the fuel control system components under their reduced electric drive signals. The reduced performance operating mode is maintained while the fault condition persists.

Abstract: An adaptive electronic throttle control system for internal combustion engine intake air rate control selectively adapts the responsiveness of the intake air rate control to maintain synchronism with other engine control systems including fuel control and dilution control systems according to the responsiveness of such other control systems and, as indicated by current engine operating conditions, according to the need to maintain synchronism to minimize emissions and maximize performance and stability.

Abstract: Control of engine speed responsive to a deviation in engine speed away from a target speed is applied selectively under closed-loop airflow control operating conditions, such as idle and coastdown operating conditions in response to analysis of a cause of an engine intake airflow deviation away from a modeled airflow. If airflow deviations are determined to have resulted from variation in internal engine friction away from a nominal friction level, the control is applied. If airflow deviations are determined to have resulted from change in internal engine airflow restriction, such as due to contaminant build-up over a period of engine use, then the control is not applied under closed-loop airflow control operating conditions to avoid overcompensating for such deviations.