Abstract: A direct injection engine is coupled to a vacuum brake booster wherein vacuum created from engine pumping is used to supplement driver braking force. The brake booster is coupled through a check valve to the engine intake manifold. A method is disclosed for estimating pressure in the brake booster based on operating conditions. A method is also disclosed for estimating operating parameters based on measured brake booster pressure. Further, a method is disclosed for diagnosing degradation, or monitoring, a brake booster pressure sensor based on operating conditions. In addition, a method is disclosed for diagnosing degradation in other vehicle and engine sensors based on measured brake booster pressure.

Abstract: A system and method for controlling an engine coupled to an emission system is provided. The system includes an emission catalyst and a HEGO sensor disposed downstream of the catalyst. The method includes adjusting an air-fuel ratio of the engine to substantially maintain an output signal from the downstream HEGO sensor within a predetermined linear operating range.

Abstract: A method for rapidly heating an emission control device in an engine exhaust uses excess air added to the exhaust via an air introduction device. After an engine cold start, the engine is operated to raise exhaust manifold temperature to a first predetermined value by operating the engine with a lean air-fuel ratio and retarded ignition timing. Once the exhaust manifold reaches the predetermined temperature value, the engine is switched to operate rich and air is added via the air introduction device. The added air and rich exhaust gas burn in the exhaust, thereby generating heat and raising catalyst temperature even more rapidly. The rich operation and excess air are continued until either engine airflow increases beyond a pre-selected value, or the emission control device reaches a desired temperature value. After the emission control device reaches the desired temperature, the engine is operated substantially around stoichiometry.

Abstract: A method for rapidly heating an emission control device in an engine exhaust uses excess air added to the exhaust via an air introduction device. After an engine cold start, the engine is operated to raise exhaust manifold temperature to a first predetermined value by operating the engine with a lean air-fuel ratio and retarded ignition timing. Once the exhaust manifold reaches the predetermined temperature value, the engine is switched to operate rich and air is added via the air introduction device. The added air and rich exhaust gas burn in the exhaust, thereby generating heat and raising catalyst temperature even more rapidly. The rich operation and excess air are continued until either engine airflow increases beyond a pre-selected value, or the emission control device reaches a desired temperature value. After the emission control device reaches the desired temperature, the engine is operated substantially around stoichiometry.

Abstract: A control system for controlling an engine (10) of an automotive vehicle has an air charge sensor (47) generating a first signal indicative of an air charge, a purge flow valve (74) generating a second signal indicative of purge flow. A controller (42) is coupled to the air charge sensor and the purge flow valve. The controller (42) is configured to determine a first amount of fuel to deliver to the cylinder based on the first signal and a desired air-fuel ratio. The controller is configured to calculate a first air-fuel ratio change value based on the first signal and is configured to calculate a second air-fuel ratio change value based on the second signal. The controller is configured to deliver a second amount of fuel to the cylinder based on the first amount of fuel and the first and second air-fuel ratio change values.

Abstract: A method for rapidly heating an emission control device in an engine exhaust uses excess air added to the exhaust via an air introduction device. After an engine cold start, the engine is operated to raise exhaust manifold temperature to a first predetermined value by operating the engine with a lean air-fuel ratio and retarded ignition timing. Once the exhaust manifold reaches the predetermined temperature value, the engine is switched to operate rich and air is added via the air introduction device. The added air and rich exhaust gas burn in the exhaust, thereby generating heat and raising catalyst temperature even more rapidly. The rich operation and excess air are continued until either engine airflow increases beyond a pre-selected value, or the emission control device reaches a desired temperature value. After the emission control device reaches the desired temperature, the engine is operated substantially around stoichiometry.

Abstract: A direct injection engine is coupled to a vacuum brake booster wherein vacuum created from engine pumping is used to supplement driver braking force. The brake booster is coupled through a check valve to the engine intake manifold. A method is disclosed for estimating pressure in the brake booster based on operating conditions. A method is also disclosed for estimating operating parameters based on measured brake booster pressure. Further, a method is disclosed for diagnosing degradation, or monitoring, a brake booster pressure sensor based on operating conditions. In addition, a method is disclosed for diagnosing degradation in other vehicle and engine sensors based on measured brake booster pressure.

Abstract: A control system for controlling an engine (10) of an automotive vehicle has an air charge sensor (47) generating a first signal indicative of an air charge, a purge flow valve (74) generating a second signal indicative of purge flow. A controller (42) is coupled to the air charge sensor and the purge flow valve. The controller (42) is configured to determine a first amount of fuel to deliver to the cylinder based on the first signal and a desired air-fuel ratio. The controller is configured to calculate a first air-fuel ratio change value based on the first signal and is configured to calculate a second air-fuel ratio change value based on the second signal. The controller is configured to deliver a second amount of fuel to the cylinder based on the first amount of fuel and the first and second air-fuel ratio change values.

Abstract: A control system and method for controlling an engine (10) of an automotive vehicle having a catalyst (34) is set forth herein. The control system maintains the efficiency of the catalyst by monitoring the catalyst state and driving the catalyst state to a target point. A first oxygen sensor (50) generates a first oxygen signal. A second oxygen sensor (52) downstream of the catalyst generates a second oxygen signal. A controller (12) is programmed to perform the steps of determining a catalyst state having a maximum value, a minimum value, and a target point therebetween; determining a commanded air-fuel ratio to drive the catalyst state to the target point; and operating the engine with the commanded air-fuel ratio.

Abstract: A direct injection engine is coupled to a vacuum brake booster wherein vacuum created from engine pumping is used to supplement driver braking force. The brake booster is coupled through a check valve to the engine intake manifold. A method is disclosed for estimating pressure in the brake booster based on operating conditions. A method is also disclosed for estimating operating parameters based on measured brake booster pressure. Further, a method is disclosed for diagnosing degradation, or monitoring, a brake booster pressure sensor based on operating conditions. In addition, a method is disclosed for diagnosing degradation in other vehicle and engine sensors based on measured brake booster pressure.

Abstract: A direct injection engine is coupled to a vacuum brake booster wherein vacuum created from engine pumping is used to supplement driver braking force. The brake booster is coupled through a check valve to the engine intake manifold. A method for estimating pressure in the brake booster uses various engine and vehicle operating conditions. A method for estimating operating parameters uses measured brake booster pressure. Further, a method for diagnosing degradation, or monitoring, a brake booster pressure sensor is based on engine or vehicle operating conditions. In addition, a method for diagnosing degradation in other vehicle and engine sensors uses measured brake booster pressure.

Abstract: In order to provide for reduced internal combustion engine exhaust emissions when cold starting an internal combustion engine, there is provided two methods and systems for cold starting an internal combustion engine, and one method and system for shutting down an internal combustion engine. The methods and systems are directed towards: (1) a preheating of a minimum of one thermally activated sensor within an internal combustion engine prior to cold starting of the internal combustion engine; (2) an autocranking of an internal combustion engine while metering fuel into the internal combustion engine and timing ignition within the internal combustion engine such as to reduce internal combustion exhaust emissions when cold starting the internal combustion engine; and (3) a phased shut down of fuel supply control followed by ignition source control when shutting down an internal combustion engine after operating the internal combustion engine.

Abstract: A valve timing system 10 is provided for dynamically suppressing cylinder knock within an internal combustion engine. The engine is of the type including several cylinders 12, each having intake and exhaust valves 14, 16. Valve timing system 10 includes a controller 24, sensors 30, and actuators 26, 28 which selectively actuate valves 14, 16 in response to signals received from controller 24. Controller 24 identifies knocking within one or more of cylinder(s) 12, and provides a modified control signal to the valve actuators 26, 28 which are associated with the identified cylinder(s). The modified control signal alters the duration in which the valves 14, 16 remain open, thereby suppressing knocking within the cylinder(s) without adversely effecting the vehicle's fuel economy or emissions.

Abstract: A direct injection engine is coupled to a vacuum brake booster wherein vacuum created from engine pumping is used to supplement driver braking force. The brake booster is coupled through a check valve to the engine intake manifold. A method is disclosed for estimating pressure in the brake booster based on operating conditions. A method is also disclosed for estimating operating parameters based on measured brake booster pressure. Further, a method is disclosed for diagnosing degradation, or monitoring, a brake booster pressure sensor based on operating conditions. In addition, a method is disclosed for diagnosing degradation in other vehicle and engine sensors based on measured brake booster pressure.

Abstract: An air/fuel control method for an engine including a NOx sensor in operative relationship to a catalytic converter. The method comprises the steps of providing a base fuel signal related to a quantity of air inducted into the engine and generating a bias signal for biasing the base fuel signal towards a leaner air/fuel ratio. The output of the NOx sensor is monitored to detect a predetermined exhaust gas NOx value representing a predefined NOx conversion efficiency. The base fuel signal is then modified as a function of the bias signal corresponding to the predetermined exhaust gas NOx value to maintain the catalytic converter within a desired efficiency range. In one aspect of the invention, the process of detecting the edge of the NOx conversion efficiency window is executed at predetermined time periods measured by the distance the vehicle traveled, or the elapsed time since last base fuel value modification.

Abstract: A method for operating a direct injection spark ignition engine in stratified mode and dual mode is presented. The method includes determining a fuel fraction in a fuel vapor canister; determining whether the fuel vapor canister should be purged; performing purge flow from the fuel vapor canister to a cylinder of the engine; and supplying purge flow and injected fuel to a cylinder of the engine during an intake stroke and supplying injected flow during a compression stroke so that the engine operates in the combined homogeneous and stratified charge mode. The method also includes controlling the purge flow and the injected fuel supplied to balance an amount of fuel supplied during the intake stroke and the compression stroke. The step of controlling calculates the amount of fuel to be injected and includes adjusting the amount of fuel supplied based on an amount of purge supplied to the cylinder.

Abstract: A method of generating a shift schedule and combustion mode schedule to optimize performance characteristics of a lean capable, multiple combustion mode engine with a time-variant after-treatment system is disclosed. The method comprises the steps of generating a lowest cost value for fuel economy and vehicle emissions as a function of an engine operating mode, wherein the engine operating mode is selected from a group consisting of a homogeneous stoichiometric mode, a homogeneous lean mode, and a stratified mode. The lowest cost value is stored in a shift schedule and combustion mode schedule along with the engine operating parameters that achieved the lowest cost value.

Abstract: Systems and methods for detecting degradation of a sensor in a vacuum brake booster coupled to a manifold of an internal combustion engine include measuring an engine or vehicle operating parameter to detect operating or control conditions and detecting degradation of the sensor based on the engine or vehicle operating parameter. In one embodiment the operating parameter is a measured or estimated manifold pressure. A pressure drop across a check valve disposed between the brake booster and the intake manifold may also be considered.

Abstract: A method and system is provided for improving the adjustment of fuel levels delivered to an internal combustion engine. A controller 15 calculates commanded air-fuel levels to deliver to the engine 13 based on a plurality of control signals, including air-fuel ratio signals measured by an air-fuel sensor 54 in the exhaust stream downstream of the engine 13. Systematic errors that reduce the accuracy of the commanded air-fuel level, including systematic errors associated with air-fuel ratio measurements, are identified and compensated for according to the present invention. Statistical methods and known operational characteristics of the air-fuel sensor are used to attribute a portion of the total system fuel error to air-fuel ratio measurement errors and such errors are compensated for to permit the calculation of a more accurate commanded air-fuel level.

Abstract: A shutdown method for an internal combustion engine having deactivatable intake and exhaust valves is disclosed in which unburned fuel existing within the engine at the time of shutdown is managed to prevent its release into the atmosphere.