Abstract: A system and method for detecting an air leak within an engine is provided. The engine includes an intake manifold communicating with an engine cylinder. The method includes measuring an exhaust gas constituent in exhaust gases from the engine when the engine is operating in an idle operating mode. The method further includes determining whether the air leak is present in the engine based on a measured exhaust gas constituent, a first air-fuel correction value, and a second air-fuel correction value.

Abstract: A system and method for controlling an engine is provided. The engine includes first and second pressure responsive devices varying compression ratios in first and second engine cylinders, respectively. The method includes commanding the first and second devices to decrease compression ratios in the first and second cylinders, respectively. The method further includes indicating when the first device has not decreased a compression ratio in the first cylinder. Finally, the method includes commanding the second device to increase a compression ratio in the second cylinder to reduce engine torque fluctuations.

Abstract: A closed throttle position of a vehicle internal combustion engine is determined by storing a plurality of signal values representative of previous foot-off position values of an accelerator pedal (10) within a normal range of pedal positions, determining a current foot-off position value of the accelerator pedal, comparing the current foot-off position value to an average of the previous stored foot-off position values, and using the average as the closed pedal position to determine a closed throttle position when the comparison is indicative of an abnormal pedal position.

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 valve assembly and method for controlling flow of gases through a passage between an engine crankcase and an engine intake manifold is provided. The method includes increasing a flow of gases through the passage between the crankcase and the intake manifold when a temperature of the gases is below a predetermined temperature.

Abstract: A method of controlling engine idle speed in a motor vehicle having an internal combustion engine and multi-ratio transmission when launched from a neutral idle rest condition. At neutral idle, the transmission is controlled such that the input and output members are decoupled. During vehicle launch from neutral idle operation, two different strategies may be employed to control engine idle speed. One preferred method is to determine a feedforward or predicted torque converter load as a function of time. Another preferred method is to determine the feedforward or predicted torque converter load by comparing a maximum engine brake torque and the torque capacity of the forward clutch at any given time. Irrespective of the particular method used, other engine torque loads are added to the feedforward or predicted torque converter load to determine the engine output torque required to control engine idle speed and provide a smooth between transmission operating modes throughout the launch period.

Abstract: A variable compression ratio control system for an internal combustion engine includes an engine driven accessory hydraulic pump and a hydraulic accumulator system for receiving hydraulic fluid from the engine driven accessory pump. The hydraulic accumulator also receives engine oil from an engine oil pump. A variable compression ratio actuator is supplied with high pressure engine lubricating oil from the hydraulic accumulator system so as to control the compression ratio of the engine.

Abstract: A method of controlling an engine 12 during engine shutdown to reduce evaporative emissions is provided. The method includes a step 50 of shutting off a fuel pump 28 of the engine 12. The method also includes a step 52 of burning off the fuel from a fuel rail 24 in a cylinder 18 of the engine 12 after the fuel pump 28 is shut off. During the burning off of the fuel, a duty cycle of each fuel injector 22of engine 12 is controlled to allow the engine 12 to operate generally cyclically about a predetermined air/fuel ratio. The predetermined air/fuel ratio is preferably stoichiometric. By burning off the fuel in the fuel rail 24 after the fuel pump 28 is shut off, the fuel pressure in the fuel rail 24 is reduced. The reduced fuel pressure in the fuel rail 24results in reduced evaporative emissions from the engine 12.

Abstract: The invention is a strategy to detect spark plug misfires in a multiple spark plug per cylinder internal combustion engine (ICE). The present invention monitors spark plug misfires for each plug within each cylinder and initiates diagnostic fault code setting and failure mode actions such as modifying spark timing and the air/fuel ratio for the cylinder with the misfiring plug to optimize emissions and performance. The strategy modifies spark timing (such as spark retard) of a spark plug not under test but within the same cylinder of the tested spark plug and tests the tested spark plug for misfire (such as changes in crankshaft velocity or acceleration). The amount of spark retard invoked can be a calibrated value such as 30 or 50 degrees off Maximum Brake Torque (MBT) timing. The invention provides improvement over the prior art in that the strategy does not require the complete disabling of a spark plug within the same cylinder as the tested spark plug.

Abstract: An engine control system includes an adaptive bias sub-system (100) that generates bias values for controlling the air-fuel ratio. The sub-system (100) includes an integral controller (118) that reads an error signal from a post-catalyst switching EGO sensor (112). A plurality of noise isolation integrators (122) filter any noise resulting from a particular engine operating condition (e.g. acceleration, deceleration, idling) from the integrated error signal and stores the signal in a corresponding keep-alive memory (124) as a bias value for that engine operating condition. In a preferred embodiment, the post-catalyst feedback loop includes a gated proportional controller 116 that turns on for a limited period of time after the post-catalyst switching EGO sensor (112) switches states.

Abstract: A system and method for adjusting fuel vapor delivery from a fuel vapor recovery system in an internal combustion engine. A requested amount of fuel vapor delivery is determined based upon a desired fuel vapor delivery amount and various system constraints, which ensure continued optimal operation of the vehicle. Purge fuel ratios are calculated by comparing desired levels to actual levels of various operating parameters. The purge fuel ratios are compared to each other to determine the minimum value from among the various purge fuel ratios, which is indicative of the most limiting system constraint. The most limiting system constraint is used to calculate an amount of fuel vapor to be delivered from the vapor recovery system.

Abstract: A magneto-strictive sensor 82 for determining a position of a valve 70 and/or a rotor 68 of an electromechanical valve assembly 46 is provided. In particular, the magneto-strictive sensor 82 is utilized to determine a rotational position of the rotor 68 and/or an axial position of the valve 70. The sensor 82 includes a sonic conduit 144 extending around a portion of a circumference of the rotor 68 of the valve assembly 46. The sensor 82 further includes a sonic wave generator 150 generating a sonic wave in the conduit 144 responsive to a transmit signal. The sonic wave propagates to a localized stress boundary 156 in the conduit 144 which is induced by a sensor magnet 80 rotating with the rotor 68. The sonic wave is reflected in the conduit 144 from the stress boundary 156. The sensor 82 further includes a sonic wave receiver 152 receiving the reflected sonic wave from the conduit 144 and generating a received signal responsive to the sonic wave.

Abstract: A method is provided for controlling an internal combustion engine in a vehicle. The method includes adjusting a fuel injection amount during engine crank based on a barometric pressure. The barometric pressure is determined from at least one signal received from at least one transmitter external from the vehicle.

Abstract: A system and method for detecting an air leak within an exhaust system is provided. The method includes measuring an exhaust gas constituent in exhaust gases from the engine when the engine is operating in an idle operating mode. The method further includes determining whether the air leak is present in the exhaust system based on a measured exhaust gas constituent, a first air-fuel correction value, and a second air-fuel correction value.

Abstract: A method for selecting one of first and second cylinder groups of an internal combustion engine is provided. The first and second cylinder groups are coupled with first and second catalytic converters, respectively. The method includes identifying one of the first and second catalytic converters by comparing first and second catalyst parameters, associated with the first and second catalytic converters, respectively, to one another. The first and second catalyst parameters indicate which one of the catalytic converters is more capable of maintaining reduced emissions while adjusting an engine operational parameter. The method further includes selecting one of the first and second cylinder groups coupled to the identified catalytic converter for changing an engine operational parameter in the selected cylinder group.

Abstract: A method for controlling the phasing of first and second air/fuel ratio oscillations in first and second cylinder groups, respectively, of an internal combustion engine is provided. The method includes determining a phase difference between the first air/fuel ratio oscillations and the second air/fuel ratio oscillations. The method further includes adjusting a phase of the first air/fuel ratio oscillations so that both first and second air/fuel ratio oscillations are at a predetermined phase offset with respect to one another, while maintaining an average air/fuel bias in the first cylinder group.

Abstract: A method for controlling first and second air/fuel ratio oscillations in first and second cylinder groups, respectively, of an internal combustion engine is provided. The method includes determining a first frequency of the first air/fuel ratio oscillations in the first cylinder group. The method further includes determining a second frequency of the second air/fuel ratio oscillations in the second cylinder group. Finally, the method includes adjusting the first frequency towards the second frequency responsive to a frequency difference between the first and second frequencies.

Abstract: A method and system are provided for monitoring exhaust gas conversion efficiency of a catalytic converter during operation of an internal combustion engine coupled to the catalytic converter. The system includes an upstream exhaust gas sensor interposed the engine and the catalytic converter for generating a first signal based on the exhaust gas upstream of the converter. A downstream exhaust gas sensor is interposed the catalytic converter and atmosphere for generating a second signal based on the exhaust gas downstream of the converter. A phase shift detector is provided for estimating a phase shift between the first and second signals. A processor is provided for aligning the first and second signals such that the resulting phase shift between the first and second signals is substantially an integer multiple of &pgr; radians and for determining conversion efficiency of the catalytic converter based such phase aligned first and second signals.

Abstract: A control system 14 for a bi-fuel engine 12 is provided. The control system 14 includes a powertrain controller 52 and a bi-fuel controller 54. The controller 52 has a set of fuel injector drivers 92. The controller 50 has a set of gasoline fuel injector drivers 104 and a set of alternate fuel (AF) fuel injector drivers 106. Each of drivers 92 in controller 52 is electrically connected to a driver 104 and a driver 106 in controller 50. Thus, a control signal generated by a single driver 92 can be utilized by either of drivers 104, 106 to generate a corresponding control signal for controlling a gasoline fuel injector 38 or a AF fuel injector 40, respectively.

Abstract: A night vision system 10 is provided for detecting objects at relatively low visible light levels. The system 10 includes an infrared light source 14. The system 10 further includes a thin sheet optical element 16 extending along a first axis 27 receiving light from the infrared light source 14 and reflecting the light generally in a first direction. Finally, the system 10 includes an infrared camera for receiving the light reflected off objects in the environment and generating a video signal responsive to the received light.