| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 123690000 | With fail-safe, backup, or malfunction means | 9 |
| 20080251057 | Abnormality diagnostic device for air-fuel ratio sensor, and control method for the device - An abnormality diagnostic device for an air-fuel ratio sensor that detects the air-fuel ratio of exhaust gas of an internal combustion engine is provided. The abnormality diagnostic device includes: a device that an device that models a system extending from a fuel injection valve to the air-fuel ratio sensor by using a first order response delay element and a waste time element, and that identifies at least a waste time of the waste time element based on an input given to the air-fuel ratio sensor and an output obtained from the air-fuel ratio sensor; and another device that performs determination about an abnormality of the waste time based on the identified waste time. | 10-16-2008 |
| 20090241925 | Air/Fuel Imbalance Monitor Using an Oxygen Sensor - Air/fuel imbalance monitoring systems and methods for monitoring air/fuel ratio imbalance of an internal combustion engine having a plurality of engine cylinders are provided herein. An example of the method may include routing exhaust gas from a first group of cylinders to an exhaust gas oxygen sensor, and during selected operating conditions, indicating that air/fuel of at least one cylinder in the first group is imbalanced based on a response of the exhaust gas oxygen sensor at frequencies at or above firing frequency of the cylinders in the first group. An example of the system may include an exhaust gas oxygen sensor positioned in such a way that exhaust gas from the group of engine cylinders are routed to the exhaust gas oxygen sensor, and a controller configured to during selected operating conditions, indicate that air/fuel of at least one cylinder in the group is imbalanced based on a response of the exhaust gas oxygen sensor at frequencies at or above firing frequency of the cylinders in the group. | 10-01-2009 |
| 20100065031 | CONTROL DEVICE FOR ENGINE - A control device for an engine includes an air-fuel ratio detector detecting an air-fuel ratio of an exhaust gas of the engine. A feedback controller performs a feedback control of an amount of a fuel injection of mixed fuel including alcohol so that the air-fuel ratio detected by the air-fuel ratio detector is come close to a target air-fuel ratio, the mixed fuel supplied from a fuel feeder. A concentration estimator estimates a concentration of the alcohol in the mixed fuel based on the air-fuel ratio of the exhaust gas and a correction amount for the amount of the fuel injection controlled by the feedback control. A malfunction determiner determines that the fuel feeder has a malfunction when the correction amount is greater than or equal to a value for a period which is longer than a first period in a second period. The second period is from a first time point when the feedback controller starts to perform the feedback control. | 03-18-2010 |
| 20100269805 | EXHAUST GAS SENSOR HEATER DEGRADATION DIAGNOSIS DEVICE - A switching element is connected between a heater of an oxygen sensor and a ground in series. A voltage sensing resistor is connected in parallel with the switching element and in series with the heater. When the switching element is in a de-energization state, if the heater degrades and a resistance of the heater changes, a heater terminal voltage (potential at middle point between heater and voltage sensing resistor) changes correspondingly. Therefore, when the switching element is in the de-energization state, a heater terminal voltage determination parameter changing in accordance with the heater terminal voltage is sensed, and a degradation determination value corresponding to a battery voltage and temperature of the heater is calculated from a map. The heater terminal voltage determination parameter is compared with the degradation determination value to determine whether the heater has degraded. | 10-28-2010 |
| 20100319667 | ABNORMALITY DETECTION APPARATUS AND ABNORMALITY DETECTION METHOD FOR AIR/FUEL RATIO SENSOR - An abnormality detection apparatus includes: an air/fuel ratio control portion that performs a control of fluctuating the air/fuel ratio; a data acquisition portion that acquires, as data for detecting abnormality, a responsiveness parameter while output of the air/fuel ratio sensor changes between rich and lean peaks during the control; an abnormality determination portion that determines presence/absence of abnormality of the sensor by using the data; and a distribution width determination portion that finds a distribution width of the data acquired by performing a plurality of acquisitions of the data, in an increase/decrease direction of the data. On the basis of comparison between the distribution width and an abnormality criterion value, the abnormality determination portion determines that the sensor has abnormality if the distribution width is less than the criterion value, and determines that the sensor does not have abnormality if the distribution width is not less than the criterion value. | 12-23-2010 |
| 20110259308 | CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE - An EG-ECU suspends fuel cutoff when the fuel cutoff is being carried out and the engine speed NE becomes lower than or equal to the resumption engine speed NErtn. The EG-ECU forcibly opens and closes an EGR valve when the fuel cutoff is being carried out, and performs abnormality diagnosis for an EGR device based on a change amount of pressure in an intake pipe caused by opening and closing the EGR valve. The EG-ECU suspends the diagnosis when the diagnosis is being carried out and the engine speed NE becomes lower than or equal to a forcible suspension engine speed NEoff. When the diagnosis is being performed, the EG-ECU sets the forcible suspension engine speed NEoff to a smaller value when the EGR valve is not in a forcibly opened state than when the EGR valve is in the forcibly opened state. Specifically, the EG-ECU sets the forcible suspension engine speed NEoff in such a manner that an allowance ΔNEallw of the forcible suspension engine speed NEoff with respect to the resumption engine speed NErtn has a smaller value when the EGR valve is not in the forcibly opened state than when the EGR valve is in the forcibly opened state. | 10-27-2011 |
| 20140238369 | HUMIDITY SENSOR DIAGNOSTICS - Embodiments for testing a humidity sensor are provided. One example method comprises indicating degradation of a humidity sensor based on a humidity sensor output and output from an intake gas composition sensor. In this way, output from the intake gas composition sensor may be used to determine if the humidity sensor is degraded. | 08-28-2014 |
| 20140238370 | HUMIDITY SENSOR DIAGNOSTICS - Embodiments for diagnosing a humidity sensor are provided. One example method comprises adjusting an engine operating parameter based on humidity of a first gas flow measured by a humidity sensor, and indicating degradation of the humidity sensor if a humidity of a second gas flow measured by the humidity sensor is different than an expected humidity. In this way, degradation of the humidity sensor may be indicated if the humidity of the second gas flow measured by the humidity sensor is different than expected. | 08-28-2014 |
| 20160115893 | ABNORMALITY DIAGNOSIS SYSTEM OF AIR-FUEL RATIO SENSOR - An abnormality diagnosis system of limit current type air-fuel ratio sensors comprises a current detecting part and a sensor temperature control device. The abnormality diagnosis system uses the current detecting part to detect the output current of the air-fuel ratio sensor when the air-fuel ratio is made the rich air-fuel ratio in the state where temperature of the air-fuel ratio is made the first temperature and when the air-fuel ratio is made the rich air-fuel ratio in the state where the temperature of the air-fuel ratio is made a second temperature higher than the first temperature. It is judged that the air-fuel ratio sensor is abnormal if the output current when the temperature of the air-fuel ratio sensor is the first temperature is larger than the output current when it is the second temperature by a predetermined value or more. | 04-28-2016 |
