Abstract: A method for estimating an oxygen concentration in an intake manifold of a diesel engine utilizing exhaust gas recirculation includes monitoring engine operation, monitoring an exhaust gas recirculation valve, and monitoring an exhaust air fuel ratio. When the engine operates in steady state with the exhaust gas recirculation valve in the closed position, a volumetric efficiency for the engine is updated. A partial pressure due to exhaust gas recirculation within the intake manifold based upon the updated volumetric efficiency is determined, and an estimated oxygen concentration within the intake manifold based upon the partial pressure due to exhaust gas recirculation within the intake manifold and the exhaust air fuel ratio is determined. Operation of the engine is controlled based upon the estimated oxygen concentration within the intake manifold.

Abstract: Four cases are to be distinguished from one another for an exhaust gas line of a motor vehicle with an oxygen storage reservoir and a lambda probe located downstream from at least part of the oxygen storage reservoir, specifically in each case, whether or not the oxygen storage reservoir has sufficient storage capacity and whether or not the lambda probe is fully serviceable. For this purpose, the exhaust gas line is supplied in an alternating sequence with rich and lean exhaust gas, in two different passes the degree of oxygen filling being varied differently. For a minor variation of the degree of oxygen filling, the serviceability of the lambda probe can be deduced on the basis of certain criteria. If the lambda probe is fully serviceable, the sufficiency or insufficiency of the oxygen storage capacity of the oxygen storage reservoir can be deduced for a greater variation of the degree of oxygen filling.

Abstract: An abnormality determination apparatus for an oxygen sensor provided on the downstream side of a catalyst includes: a first determination portion that determines whether a rich-output continuation time during which output value of the oxygen sensor continues being an output value that shows a rich state before a fuel cut is started is longer than a set continuation time; a second determination portion that determines whether degree of change in the output value when the output value changes from a first reference value to a second reference value that shows a leaner state than the first reference value is more gradual than a set degree of change after the fuel cut is started; and a third determination portion that determines whether the oxygen sensor is abnormal based on determinations by the first determination portion the second determination portion.

Abstract: A sensor including a sensor element including a plurality of electrode terminals, terminal metal fittings, a terminal surrounding member, and lead wires connected to respective terminal metal fittings. The terminal surrounding member is divided into a front side surrounding member and a rear side surrounding member in the front-rear direction, and a rear end face of the front side surrounding member abuts a front end face of the rear side surrounding member. At least one of the terminal metal fittings includes a protruding piece portion protruding in a lateral direction and held between the rear end face of the front side surrounding member and the front end face of the rear side surrounding member.

Abstract: In the calibration of a lambda sensor (26), inaccuracies occur during a fuel cut-off overrun phase depending on the temperature. A method is proposed for correcting an output signal of a lambda sensor (16) of an internal combustion engine (1), having the following steps: detection of a fuel cut-off overrun phase of the internal combustion engine (1), sensing of an exhaust-gas composition by the lambda sensor (16) during the fuel cut-off overrun phase, sensing of a temperature which represents a measure of the intake air of the internal combustion engine (1), calibration of the lambda sensor (16) based on the second temperature.

Abstract: An engine control system includes an oxygen (O2) sensor diagnostic module that diagnoses an O2 sensor and requests a minimum air per cylinder (APC). A throttle actuator module controls a throttle to adjust a mass air flow based on the minimum APC.

Abstract: An abnormality determination apparatus for an oxygen sensor provided on the downstream side of a catalyst includes: a first determination portion that determines whether amount of decline in output value of the oxygen sensor during a period from when amount of intake air or exhaust gas declines before a fuel cut is started to when the fuel cut is started is smaller than a reference amount of decline; a second determination portion that determines whether degree of change in the output value when the output value changes from a first reference value to a second reference value that shows a leaner state than the first reference value is more gradual than a set degree of change after the fuel cut is started; and a third determination portion that determines whether the oxygen sensor is abnormal based on determinations by the first determination portion the second determination portion.

Abstract: An abnormality detection device for an internal combustion engine capable of performing abnormality detection with accuracy, and an air/fuel ratio control apparatus for an internal combustion engine capable of performing air/fuel ratio control with accuracy. An estimated value of the amount of intake air at a valve closing time at which an intake value is closed, is computed. The in-cylinder air/fuel ratio in a cylinder is computed by using the estimated value. The obtained in-cylinder air/fuel ratio is used as an input air/fuel ratio to identify a parameter in a primary delay element. Determination as to the existence/nonexistence of an abnormality in a pre-catalyst sensor (A/F sensor) is made on the basis of the obtained parameter.

Abstract: A method for detecting faults in an air system of an internal combustion engine having an intake manifold and an exhaust manifold includes, but is not limited to the steps of measuring an oxygen concentration of the gas flowing in the exhaust manifold, estimating an intake oxygen control value in the intake manifold and estimating an intake oxygen reference value in the intake manifold based on said oxygen concentration of the gas flowing in the exhaust manifold. The method further includes, but is not limited to the steps of calculating an intake deviation value as a difference between the intake oxygen control value and the intake oxygen reference value and verifying if the intake deviation value is greater than a predetermined first threshold.

Abstract: A fuel control approach that compensates for time delays to increase exhaust gas sensor feedback response speed.

Abstract: An oxygen sensor circuit comprises an oxygen sensor, a bias voltage module, and a switch module. The bias voltage module communicates with the oxygen sensor and generates a bias voltage. The switch module selectively connects the bias voltage module to the oxygen sensor.

Abstract: A method for estimating the oxygen concentration in an internal combustion engine that includes, but is not limited to an intake manifold, an exhaust manifold, an EGR system, a throttle valve, an air mass sensor for measuring a fresh air flow ({dot over (m)}thr) entering the intake manifold through the throttle valve, and cylinders.

Abstract: A diagnostic system for an engine includes a stage transition module and a control module. The stage transition module generates a command signal based on a fuel control signal. The command signal commands a fuel system of the engine to intrusively transition between rich and lean states during a diagnostic test that includes first, second, and third stages. The first, second, and third stages are defined based on transitions between the rich and lean states. The control module during the second and third stages detects: an error with a first oxygen sensor based on a comparison between the command signal and a first oxygen signal from the first oxygen sensor; an error with a second oxygen sensor based on a second oxygen signal from the second oxygen sensor; and an error with a catalytic converter based on the first and second oxygen signals and a manifold absolute pressure signal.

Abstract: A NOx sensor abnormality detection device senses a NOx concentration and an O2 concentration from output signals of a NOx sensor and calculates an estimated NOx concentration from the O2 concentration when an engine is in a steady operation state, when a zero point of the NOx concentration is sensed, and when an O2 sensing section of the NOx sensor is normal. The NOx sensor abnormality detection device calculates a sensed inclination and an estimated inclination of a NOx concentration output characteristic of the NOx sensor based on the sensed NOx concentration, the sensed O2 concentration and the estimated NOx concentration calculated from the O2 concentration. The NOx sensor abnormality detection device determines that the NOx sensor is faulty when an absolute value of a difference between the sensed inclination and the estimated inclination is larger than a predetermined value.

Abstract: Method for determining the oxygen storage capacity of a catalytic converter for a motor vehicle using the signals of an oxygen probe upstream and an oxygen probe downstream from the catalytic converter which has the following steps of determining of a delay time which is dependent on the oxygen storage capacity between the signal of the oxygen probe upstream and the signal of the oxygen probe downstream from the catalytic converter, determining of the phase shift which is dependent on the oxygen probe dynamics between the signal of the oxygen probe upstream and the signal of the oxygen probe downstream from the catalytic converter, and correcting the determined delay time between the signal of the oxygen probe upstream and the signal of the oxygen probe downstream from the catalytic converter by a determined phase shift.

Abstract: A system includes a cylinder equivalence ratio (EQR) module, a location estimation module, a sensor module, and a fuel control module. The cylinder EQR module determines a first EQR corresponding to a first exhaust gas expelled from a first cylinder and determines a second EQR corresponding to a second exhaust gas expelled from a second cylinder. The location estimation module determines when the first and second exhaust gases mix in an exhaust manifold to form a third exhaust gas having a third EQR. The sensor module estimates an EQR of a fourth exhaust gas based on the third EQR. The fourth exhaust gas is located at an oxygen sensor in the exhaust manifold. The fuel control module controls an amount of fuel supplied to an engine based on a difference between the estimated EQR and an EQR corresponding to measurements from the oxygen sensor.

Abstract: A system for compensating for changes in behavior of an oxygen sensor. In one embodiment, the system includes an oxygen sensor configured to produce an output indicative of an oxygen level in an exhaust stream produced by an internal combustion engine. An electronic control unit receives the output of the oxygen sensor and is configured to cause the internal combustion engine to operate in an overrun mode. The electronic control unit is programmed or otherwise configured to determine whether a change in oxygen level over time is approximately zero. When the change in oxygen level is approximately zero or near zero, the electronic control unit determines a compensation factor for the oxygen sensor.

Abstract: An internal combustion engine includes an exhaust system, an oxygen sensor in the exhaust system and a sensor malfunction monitor. The sensor malfunction monitor measures a rate of change of a signal from the sensor on detecting a turning point of the signal and detects a malfunction when a rate of change of the signal exceeds a threshold. Alternatively, the sensor malfunction monitor measures a response time interval starting from a point in time at which a diagnostic function begins to force an air-fuel ratio to change (e.g., from lean-to-rich or rich-to-lean) and ends at a point in time when a turning point of the signal is detected. The sensor malfunction monitor detects a malfunction when the delay time of the response time interval, or average delay time from a plurality of measured response time intervals, exceeds a time threshold.

Abstract: There is provided a dither control means that performs a dither control, which compulsively changes an air-fuel ratio alternately to rich side and to lean side by increasing and decreasing fuel injection quantity of an injector (fuel injection valve) in a stepped manner. A predicted value (ideal A/F value ID), which indicates an ideal change of a detection value of an A/F sensor (oxygen concentration sensor) in a case where the A/F sensor is not degraded, is set as a standard value. Then, an integral of a difference between the detection value of the A/F sensor, which changes in accordance with the dither control, and the standard value is calculated. If a calculated value of the integral is larger than a predetermined value, it is determined that the A/F sensor is degraded.

Abstract: Methods for monitoring and detecting undesired exotherms which may occur in an exhaust aftertreatment system coupled to a lean burning combustion engine are described. In one particular approach, an undesired exotherm may be indicated based on an expected oxygen depletion along a length of an exhaust aftertreatment system in the direction of exhaust gas flow of exhaust gas. For example, during DPF regeneration, a certain amount of oxygen is expected to be utilized for removing soot. If less oxygen is actually found in the exhaust downstream of the exhaust system, then an undesired exotherm may be present, as unintended reductant may be present in the exhaust and reacting exothermically with oxygen. Various mitigation actions may then be initiated in response to the indication of an undesired exotherm.

Abstract: Depending on a trim controller diagnosis, a suspicion marker for an asymmetric ageing of the exhaust gas probe is allocated either a “true” value or a “false” value and, if the value of the suspicion marker is “true”, a dynamic diagnosis will be performed based on the exhaust gas probe's measuring signal, on the basis of the results of which diagnosis either an asymmetrically aged or a non-asymmetrically aged exhaust gas probe will be detected.

Abstract: Data on a secular change of each denitration catalyst is managed based on data obtained by a periodic maintenance and a daily management. Management of a secular change and prediction on performance variations that occur until a next periodic check is performed. It is determined whether the denitration catalyst is deteriorated such that an exhaust-gas denitration system cannot maintain its performance. When the denitration catalyst is deteriorated, regeneration, replacement, or addition of the denitration catalyst is performed, and the denitration catalyst is altered as necessary. When the denitration catalyst is usable, the denitration catalyst is not replaced nor regenerated.

Abstract: A light modifying ceramic composition comprises an oxygen permeable sol-gel matrix and a lumophore held on the matrix. In particular, the lumophore of the invention is a hexanuclear molybdenum/tungsten core having 12 anionic ligands and two ligands that are uncharged. Uncharged ligands include organic nitriles, organic phosphines, and organic arsines. In one embodiment, the ceramic composition containing the lumophore and the sol-gel matrix is applied to the end of an optical fiber to provide a remote oxygen sensor. The sensors are useful for in situ biological monitoring of oxygen either in vivo or in vitro, and in time dependent control of combustion processes such as an automobile or power plant.

Abstract: The invention concerns a procedure to determine the oxygen storage capability of an emission control system with an exhaust gas sensor with discrete-level ability disposed in front of the emission control system. If in a period of time before the determination of the oxygen storage capability, the control intervention of the exhaust gas sensor is ascertained, and if this mean value is taken into consideration when calculating the fuel-delivery control phase during the determination of the oxygen storage capability of the emission control system, or if this mean value is used to correct the lambda value used to calculate the amount of oxygen stored, an improved measuring accuracy can be achieved while using a cost effective discrete level sensor.

Abstract: To avoid potentially erroneous results, monitoring the operation of an oxygen sensor of an internal combustion engine of a motor vehicle to detect a slow response of the oxygen sensor as indicative of an oxygen sensor fault is temporarily suspended in response to a brake operation transition of a braking system of the vehicle.

Abstract: Methods and systems for detecting faults with nitrogen oxides sensors used to detect the presence of nitrogen oxides in an exhaust effluent gas stream emitted from a combustion engine during its operation include providing a virtual nitrogen oxides sensor measurement compared with actual nitrogen oxides content measured by nitrogen oxides sensors.

Abstract: An abnormality determination apparatus for an oxygen sensor provided on the downstream side of a catalyst includes: a first determination portion that determines whether a rich-output continuation time during which output value of the oxygen sensor continues being an output value that shows a rich state before a fuel cut is started is longer than a set continuation time; a second determination portion that determines whether degree of change in the output value when the output value changes from a first reference value to a second reference value that shows a leaner state than the first reference value is more gradual than a set degree of change after the fuel cut is started; and a third determination portion that determines whether the oxygen sensor is abnormal based on determinations by the first determination portion the second determination portion.

Abstract: A diagnostic system for an engine includes an oxygen detection module, a timing module and a control module. The oxygen detection module receives an oxygen signal from an oxygen sensor that detects an oxygen level in an exhaust system of the engine. The oxygen signal has N rich states and M lean states, where N and M are integers greater than or equal to 1. The timing module determines a rich period that the oxygen signal is in at least one of the N rich states and determines a lean period that the oxygen signal is in at least one of the M lean states. The control module detects an asymmetrical error with the oxygen sensor based on a comparison between the rich period and the lean period.

Abstract: The invention concerns a method for determining the composition of a fuel mixture from a first and at least a second fuel for operating a combustion engine, whereby the fuel mixtures of different compositions require various air/fuel ratios to achieve a stoichiometric combustion. Thereby it is provided that the air volume that has been delivered to the combustion engine, the fuel quantity that has been delivered and the oxygen content in the exhaust gas of the combustion engine are determined during one or several stationary operating phases of the combustion engine during one or several measuring phases, and in that the composition of the fuel mixture is determined from these values. The procedure allows an accurate and reliable determination of the composition of a fuel mixture for combustion engines that are operated in flex-fuel-mode.

Abstract: An oxygen sensor device and method for a motor vehicle having an electrode within an outer shell for measuring oxygen in exhaust gas exiting the vehicle. A communication device, powered by a capacitor, wirelessly transmits the measured amount of oxygen from the electrode to a powertrain control module. Vibration transmitting from the motor vehicle shakes a magnet, wound inside a coil, for generating the electrical current used by the capacitor.

Abstract: An oxygen sensor circuit comprises an oxygen sensor, a bias voltage module, and a switch module. The bias voltage module communicates with the oxygen sensor and generates a bias voltage. The switch module selectively connects the bias voltage module to the oxygen sensor.

Abstract: A sensor including a sensor element including a plurality of electrode terminals, terminal metal fittings, a terminal surrounding member, and lead wires connected to respective terminal metal fittings. The terminal surrounding member is divided into a front side surrounding member and a rear side surrounding member in the front-rear direction, and a rear end face of the front side surrounding member abuts a front end face of the rear side surrounding member. At least one of the terminal metal fittings includes a protruding piece portion protruding in a lateral direction and held between the rear end face of the front side surrounding member and the front end face of the rear side surrounding member.

Abstract: It is an object of the present invention to provide a gas concentration detection apparatus that is capable of forming an accurate activity judgment when a gas concentration detection cell begins to detect gas concentration with high accuracy. When warm-up begins at time t0 in a NOx concentration detection apparatus that achieves NOx concentration detection with a NOx sensor cell after excess oxygen is discharged by an oxygen pump cell, a NOx sensor cell output begins to rise at time t1. Subsequently, at time t2, an oxygen pump cell output begins to rise. An inflection point appearing in the NOx sensor cell output is then located. At time t5 at which the inflection point appears, an activity judgment about the NOx sensor cell is formed.

Abstract: An air/fuel imbalance (AFIM) diagnostic system comprises a first module, an imbalance determination module, and an imbalance diagnostic module. The first module outputs imbalance data samples based on an oxygen signal provided by an oxygen sensor measuring oxygen in exhaust expelled from cylinders of a cylinder bank. The imbalance determination module determines an AFIM value based on the imbalance data samples. The imbalance diagnostic module selectively diagnoses an AFIM in the cylinder bank based on the AFIM value.

Abstract: A method for estimating the oxygen concentration in an internal combustion engine that includes, but is not limited to an intake manifold, an exhaust manifold, an EGR system, a throttle valve, an air mass sensor for measuring a fresh air flow ({dot over (m)}thr) entering the intake manifold through the throttle valve, and cylinders.

Abstract: An oxygen concentration sensor is disposed in an engine exhaust passageway. The alcohol concentration in the fuel used in the internal combustion engine is detected. A target impedance is set on the basis of the detected alcohol concentration. The actual impedance of a sensor element of the oxygen concentration sensor is detected. The heater output of the exhaust gas sensor is controlled so that the actual impedance becomes equal to the target impedance, whereby the temperature of the sensor element represented by the impedance becomes equal to a target temperature represented by the target impedance.

Abstract: A method for detecting faults in an air system of an internal combustion engine having an intake manifold and an exhaust manifold includes, but is not limited to the steps of measuring an oxygen concentration of the gas flowing in the exhaust manifold, estimating an intake oxygen control value in the intake manifold and estimating an intake oxygen reference value in the intake manifold based on said oxygen concentration of the gas flowing in the exhaust manifold. The method further includes, but is not limited to the steps of calculating an intake deviation value as a difference between the intake oxygen control value and the intake oxygen reference value and verifying if the intake deviation value is greater than a predetermined first threshold.

Abstract: The invention concerns a procedure and a device for diagnosing the dynamic of an exhaust gas sensor, which is arranged in an exhaust gas duct of a combustion engine and with which a parameter of the gas mixture that is supplied to the combustion engine is regulated by a control loop. It is thereby provided according to the invention that during a diagnosing period a temporal deflection of a regulation correcting variable for the parameter that is derived from an output signal of the exhaust gas sensor or a temporal course of the output signal of the exhaust gas sensor is used for the diagnosis and that the dynamic of the exhaust gas sensor is assumed in an evaluation algorithm. Thereby an improvement of the on-board diagnosis of the dynamic of the exhaust gas sensor can be achieved and in particular lambda probes, which provide a slowing down of their responding behavior, can be detected early on.

Abstract: A NOx sensor abnormality detection device senses a NOx concentration and an O2 concentration from output signals of a NOx sensor and calculates an estimated NOx concentration from the O2 concentration when an engine is in a steady operation state, when a zero point of the NOx concentration is sensed, and when an O2 sensing section of the NOx sensor is normal. The NOx sensor abnormality detection device calculates a sensed inclination and an estimated inclination of a NOx concentration output characteristic of the NOx sensor based on the sensed NOx concentration, the sensed O2 concentration and the estimated NOx concentration calculated from the O2 concentration. The NOx sensor abnormality detection device determines that the NOx sensor is faulty when an absolute value of a difference between the sensed inclination and the estimated inclination is larger than a predetermined value.

Abstract: A sensor element for determining different gas components in a test gas, in particular in an exhaust gas of an internal combustion engine, including a lambda sensor for determining an oxygen content in the test gas, at least one semiconductor gas sensor for determining at least one further gas component in the test gas, and a multiplexer which is connected to the semiconductor gas sensor.

Abstract: An apparatus for diagnosing malfunctioning which is applied to an internal combustion engine having a catalyst, an air-fuel ratio sensor, and an oxygen sensor is disclosed. The apparatus diagnoses whether the oxygen sensor is malfunctioning on the basis of a change in an output value of the oxygen sensor within a predetermined period of time after the output value has started changing towards a lean side after the start of fuel cutoff. The apparatus is provided with a first determination section and a second determination section. The first determination section determines whether fresh air has reached the air-fuel ratio sensor after the start of the fuel cutoff. The second determination section determines whether or not to carry out diagnosis of malfunctioning on the basis of the output value of the oxygen sensor immediately after the first determination section has determined that fresh air has reached the air-fuel ratio sensor.

Abstract: An internal combustion engine includes an exhaust system, an oxygen sensor in the exhaust system and a sensor malfunction monitor. The sensor malfunction monitor measures a rate of change of a signal from the sensor on detecting a turning point of the signal and detects a malfunction when a rate of change of the signal exceeds a threshold.

Abstract: A fuel injection system includes a fuel tank, a supply line, a fuel injection rail and a number of fuel injectors. The fuel tank includes a fuel tank module which houses a fuel pump. The fuel pressure within the fuel injection system is monitored by a pressure sensor which is integrated into a quick connector between the fuel supply line and the fuel tank module.

Abstract: A determining section integrates amount of oxygen that is stored in or released from a exhaust gas purifying catalyst from when a signal from an oxygen sensor is changed until when the signal is changed subsequently, thereby calculating an oxygen storage capacity. The determining section uses the calculated oxygen storage capacity to determine a deterioration state of the exhaust gas purifying catalyst. A limiting section sets, as an allowable change amount, a change amount of the air-fuel ratio that corresponds to an allowable maximum fluctuation amount of a torque of a output shaft of the engine. The limiting section limits a change of the target air-fuel ratio such that a change amount of the target air-fuel ratio due to a change of the signal does not exceed the allowable change amount. Therefore, a deterioration of a drivability while ensuring opportunities of detecting a deterioration of an exhaust gas purifying catalyst is suppressed.

Abstract: A method for diagnosing the dynamic characteristics of a lambda sensor, which is used at least intermittently for a cylinder-individual lambda closed-loop control, which provides for at least one actuating variable of the lambda closed-loop control to be detected and compared to a specifiable maximum threshold, and, if the maximum threshold is exceeded, the dynamic response of the lambda sensor is deemed insufficient with respect to the usability for the cylinder-individual lambda closed-loop control.

Abstract: In an excessive burn detection method for detecting an excessive burn during a regeneration process, in which particulates accumulated in a particulate filter arranged in an exhaust passage of a diesel engine are burned and removed for regenerating the particulate filter, an oxygen concentration in exhaust gas in the exhaust passage downstream of the particulate filter is measured in predetermined time intervals after the regeneration process starts and it is determined whether the excessive burn occurs by determining whether the measured oxygen concentration decreases with a predetermined tendency.

Abstract: The invention relates to a method for determining the actual oxygen load of a 3-path catalyst of a lambda-controlled internal combustion engine, whereby a value for the actual oxygen load is calculated from the signal of a pre-catalyst lambda probe and the measured air mass flow rate by integration over time, whereby the post-catalyst lambda probe is initialized when the signal is interrupted.

Abstract: An engine exhaust sensor diagnostic system for an exhaust system including a catalyst and a post-catalyst oxygen sensor includes a first module that calculates a total integrated area based on a signal generated by the post-catalyst oxygen sensor. A second module compares the total integrated area to a threshold integrated area and generates a pass status signal when the total integrated area is less than the threshold integrated area.