Abstract: A method for controlling reductant added to an exhaust of an engine having a lean NOx catalyst and a particulate filter adjusts a reductant amount during particulate filter regeneration. The method adjusts the reductant amount to account for reducing agents released from the particulate filter that are experienced by the lean NOx catalyst. In addition, management of particulate filter regeneration is based on both an estimated amount of stored particles and conditions of the lean NOx catalyst. In this way, operation of both the particulate filter and the lean NOx catalyst can be optimized. Also, termination of particulate filter regeneration is determined based on operating conditions.

Abstract: An electronic throttle control system is described where a throttle position sensor has multiple slopes depending on the operating region. At low throttle positions, a greater slope, and thus a greater sensitivity is provided, thereby increasing control resolution. At greater throttle positions, a lower slope, and thus lower sensitivity is provided. In this way, an output signal that varies across the entire operating region of the throttle is provided for monitoring and control, while improved performance at low throttle angles can be simultaneously achieved. A method for learning a transition region is also desribed.

Abstract: A fuel vapor purging method controls fuel vapor purging during stratified operation. Several factors influence vapor purge control, including fuel vapor concentration in the cylinder and temperature of the emission control device. The fuel vapor passes through the cylinder unburned by maintaining the concentration within allowable limits. The unburned fuel vapor reacts exothermically in the emission control device thereby generating heat. To guarantee that the fuel vapor reacts in the first emission control device, the fuel vapor purge is restricted to a certain temperature range. To guarantee that the fuel vapor does not burn in the cylinder, the concentration is kept to a restricted value.

Abstract: A method for controlling the air/fuel ratio of an internal combustion engine uses a manifold pressure sensor and an exhaust gas recirculation system having an orifice and a exhaust pressure sensor located upstream of the orifice. Both the manifold pressure sensor and the exhaust pressure sensor are sampled synchronously with a frequency proportional to the firing frequency of the engine and then filtered to eliminate unwanted frequencies. The sampled signals obtained then have the necessary bandwidth needed for closed loop control of the exhaust gas recirculation flow and engine air/fuel ratio control.

Abstract: A fuel vapor purging method controls fuel vapor purging during stratified operation. Several factors influence vapor purge control, including fuel vapor concentration in the cylinder and temperature of the emission control device. The fuel vapor passes through the cylinder unburned by maintaining the concentration within allowable limits. The unburned fuel vapor reacts exothermically in the emission control device thereby generating heat. To guarantee that the fuel vapor reacts in the first emission control device, the fuel vapor purge is restricted to a certain temperature range. To guarantee that the fuel vapor does not burn in the cylinder, the concentration is kept to a restricted value.

Abstract: A method of controlling intake manifold pressure during startup of a direct injection engine permits a decrease in instantaneous cylinder pressure by reducing intake manifold pressure thereby increasing the time available for fuel injection during the compression stroke, which allows sufficient fuel to be injected at the lower fuel pressures present during starting of this engine.

Abstract: A fuel vapor purging method controls fuel vapor purging during stratified operation. Several factors influence vapor purge control, including fuel vapor concentration in the cylinder and temperature of the emission control device. The fuel vapor passes through the cylinder unburned by maintaining the concentration within allowable limits. The unburned fuel vapor reacts exothermically in the emission control device thereby generating heat. To guarantee that the fuel vapor reacts in the first emission control device, the fuel vapor purge is restricted to a certain temperature range. To guarantee that the fuel vapor does not burn in the cylinder, the concentration is kept to a restricted value.

Abstract: A method is presented for correcting estimates of engine output torque and accessory load torque. Engine output torque estimates are corrected when the accessory is disengaged from the engine. Accessory load torque is learned, or corrected, when the accessory is engaged to the engine. In one example, these corrections are made when engine output torque is known to be substantially zero from torque converter speed ratio or from the timing of the overrunning clutch engagement. This information is then used to control engine output torque to improve drive feel and vehicle performance.

Abstract: A method for controlling an engine having both an electronically controlled inlet device, such as an electronic throttle unite, and an electronically controlled outlet device, such as a variable cam timing system is disclosed. The method of the present invention achieves cylinder air charge control that is faster than possible by using an inlet device alone. In other words, the method of the present invention controls cylinder air charge faster than manifold dynamics by coordination of the inlet and outlet device. This improved control is used to improve various engine control functions.

Abstract: A method for controlling mode transitions, such as from stratified to homnogeneous mode, in a direct injection engine adjusts a number of cylinders carrying out combustion to prevent engine torque disturbances. Cylinder activation or deactivation is used when changes in cylinder air/fuel ratio cannot be compensated using ignition timing adjustments. In addition, the number of cylinders to activate or deactivate is also determined.

Abstract: A method for controlling reductant added to an exhaust of an engine having a lean NOx catalyst and a particulate filter adjusts a reductant amount during particulate filter regeneration. The method adjusts the reductant amount to account for reducing agents released from the particulate filter that are experienced by the lean NOx catalyst. In addition, management of particulate filter regeneration is based on both an estimated amount of stored particles and conditions of the lean NOx catalyst. In this way, operation of both the particulate filter and the lean NOx catalyst can be optimized. Also, termination of particulate filter regeneration is determined based on operating conditions.

Abstract: A vehicle and engine control system controls engine torque to maintain positive torque at a transmission input to prevent the transmission gears from separating. By maintaining a positive engine torque, the transmission is prevented from operating in or through the zero torque, or lash, zone. This prevents poor vehicle driveability that would otherwise result from operation in the lash zone. The control systems uses closed loop control based on a desired and actual turbine speed ratio, or slip ratio, to guarantee positive torque applied to the transmission.

Abstract: A fuel vapor purging method controls fuel vapor purging during stratified operation. Several factors influence vapor purge control, including fuel vapor concentration in the cylinder and temperature of the emission control device. The fuel vapor passes through the cylinder unburned by maintaining the concentration within allowable limits. The unburned fuel vapor reacts exothermically in the emission control device thereby generating heat. To guarantee that the fuel vapor reacts in the first emission control device, the fuel vapor purge is restricted to a certain temperature range. To guarantee that the fuel vapor does not burn in the cylinder, the concentration is kept to a restricted value.

Abstract: A fuel vapor purging method controls fuel vapor purging during stratified operation. Several factors influence vapor purge control, including fuel vapor concentration in the cylinder and temperature of the emission control device. The fuel vapor passes through the cylinder unburned by maintaining the concentration within allowable limits. The unburned fuel vapor reacts exothermically in the emission control device thereby generating heat. To guarantee that the fuel vapor reacts in the first emission control device, the fuel vapor purge is restricted to a certain temperature range. To guarantee that the fuel vapor does not burn in the cylinder, the concentration is kept to a restricted value.

Abstract: A nitrous oxide trap temperature control system for desulfating the trap uses and engine with some cylinders operating with lean combustion and some cylinders operating with rich combustion. The lean and rich combustion gases are combined to form an mixture which is fed to the trap to provide an exothermic reaction. The desired lean and rich air/fuel ratios of the respective lean and rich cylinders are limited depending on trap temperature and incremental heat addition to prevent inadvertently decreasing trap temperature.

Abstract: A method for controlling an engine having both an electronically controlled inlet device, such as an electronic throttle unit, and an electronically controlled outlet device, such as a variable cam timing system is disclosed. The method of the present invention achieves cylinder air charge control that is faster than possible by using an inlet device alone. In other words, the method of the present invention controls cylinder air charge faster than manifold dynamics by coordination of the inlet and outlet device. This improved control is used to improve various engine control functions.

Abstract: An exhaust gas recirculation systems directs exhaust gasses from an exhaust manifold to an intake manifold of an internal combustion engine. The exhaust gasses travel from the exhaust manifold, first passing through a flow control valve and then through a measuring orifice before entering the intake manifold. Pressure difference across the orifice is used, along with correction factors based on the pressure difference and pressure downstream of the orifice, to measure and control exhaust gas flow.

Abstract: A reductant injection control strategy for controlling an amount of nitrogen oxide reducing agent injected upstream of a first and second serially placed nitrogen oxide catalyst, calculates the reductant injection For the first catalyst and second catalyst. The reductant injection for the first catalyst is based on engine operating conditions. The reductant injection for the second catalyst is based on the reductant injection for the first catalyst and a conversion efficiency of the first catalyst.

Abstract: A speed control method for vehicles having an internal combustion engine smoothly controls engine torque to control vehicle speed. Torque is controlled via airflow in a first torque control range. Torque is controlled via a coordination of air/fuel ratio, ignition timing, and cylinder deactivation is a second torque control range. The torque range is selected based on the required airflow to deliver the required torque. If the required airflow is less than a lower allowable value, then the airflow is fixed at this lower allowable value and the second range is selected. Otherwise, the first range is selected.

Abstract: A fuel vapor purging method controls fuel vapor purging during stratified operation. Several factors influence vapor purge control, including fuel vapor concentration in the cylinder and temperature of the emission control device. The fuel vapor passes through the cylinder unburned by maintaining the concentration within allowable limits. The unburned fuel vapor reacts exothermically in the emission control device thereby generating heat. To guarantee that the fuel vapor reacts in the first emission control device, the fuel vapor purge is restricted to a certain temperature range. To guarantee that the fuel vapor does not burn in the cylinder, the concentration is kept to a restricted value.