JP2016061681A - O2 sensor fault diagnosis device - Google Patents

O2 sensor fault diagnosis device Download PDF

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JP2016061681A
JP2016061681A JP2014189978A JP2014189978A JP2016061681A JP 2016061681 A JP2016061681 A JP 2016061681A JP 2014189978 A JP2014189978 A JP 2014189978A JP 2014189978 A JP2014189978 A JP 2014189978A JP 2016061681 A JP2016061681 A JP 2016061681A
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Prior art keywords
sensor
temperature
failure diagnosis
failure
engine
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JP2014189978A
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JP6112619B2 (en
Inventor
卓大 北村
Takahiro Kitamura
卓大 北村
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本田技研工業株式会社
Honda Motor Co Ltd
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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N11/00Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/14Introducing closed-loop corrections
    • F02D41/1438Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1454Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/14Introducing closed-loop corrections
    • F02D41/1438Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1493Details
    • F02D41/1495Detection of abnormalities in the air/fuel ratio feedback system
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2550/00Monitoring or diagnosing the deterioration of exhaust systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2560/00Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/02Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
    • F01N2560/025Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting O2, e.g. lambda sensors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2900/00Details of electrical control or of the monitoring of the exhaust gas treating apparatus
    • F01N2900/04Methods of control or diagnosing
    • F01N2900/0416Methods of control or diagnosing using the state of a sensor, e.g. of an exhaust gas sensor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D2200/00Input parameters for engine control
    • F02D2200/02Input parameters for engine control the parameters being related to the engine
    • F02D2200/021Engine temperature
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/04Introducing corrections for particular operating conditions
    • F02D41/06Introducing corrections for particular operating conditions for engine starting or warming up
    • F02D41/062Introducing corrections for particular operating conditions for engine starting or warming up for starting
    • F02D41/064Introducing corrections for particular operating conditions for engine starting or warming up for starting at cold start
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/40Engine management systems

Abstract

A fault diagnosis device for an O2 sensor capable of performing an accurate diagnosis without consuming electric power while the engine is stopped.
An O2 sensor that activates at a predetermined temperature or more and measures an oxygen concentration of combustion gas of the engine, an O2 sensor temperature estimation means that estimates the temperature of the O2 sensor, and an output voltage V of the O2 sensor. And an O2 sensor failure diagnosing device 23 having an O2 sensor failure diagnosing unit 23 for diagnosing a failure of the O2 sensor 12 based on the temperature estimated and detected by the O2 sensor temperature estimating unit 22. The temperature of the O2 sensor 12 is estimated and detected based on the water cooling water temperature TW. The O2 sensor failure diagnosing means 23 indicates that a failure has occurred in the O2 sensor 12 when the coolant temperature TW is equal to or lower than the first predetermined temperature TW1 and the output voltage V of the O2 sensor 12 is a value detected in the activated state. Diagnose.
[Selection] Figure 3

Description

  The present invention relates to an O2 sensor failure diagnosis apparatus, and more particularly to an O2 sensor failure diagnosis apparatus that detects the oxygen concentration of combustion gas discharged from an engine.

  2. Description of the Related Art Conventionally, O2 sensor failure diagnosis devices that detect the oxygen concentration of combustion gas discharged from an engine are known.

  Patent Document 1 utilizes the characteristic of an O2 sensor that can obtain a desired sensor output only while being heated by an engine or combustion gas and above the activation temperature, and the temperature of the O2 sensor falls below the activation temperature. However, there is disclosed an O2 sensor failure diagnosis apparatus that determines that an abnormality has occurred in the O2 sensor when there is a sensor output that is equal to or higher than the activation temperature.

JP 2001-004580 A

  However, since the technique described in Patent Document 1 is a method of detecting by detecting that the temperature of the O2 sensor has become sufficiently lower than the activation temperature based on the elapsed time after the engine is stopped, the technique has elapsed even while the engine is stopped. There is a problem that it is necessary to continue driving a control device including a timer for measuring time, and the power of the in-vehicle battery is consumed even when the engine is stopped.

  An object of the present invention is to solve the above-mentioned problems of the prior art and provide an O2 sensor failure diagnosis apparatus that can perform an accurate diagnosis without consuming electric power while the engine is stopped.

  In order to achieve the above object, the present invention provides an O2 sensor (12) which is activated at a predetermined temperature or higher and measures the oxygen concentration of engine combustion gas, and an O2 sensor which estimates and detects the temperature of the O2 sensor (12). O2 for diagnosing failure of the O2 sensor (12) based on the temperature estimation means (22), the output voltage (V) of the O2 sensor (12) and the temperature estimated and detected by the O2 sensor temperature estimation means (22) In the O2 sensor failure diagnosing apparatus having the sensor failure diagnosing means (23), the O2 sensor temperature estimating means (22) is configured to detect the O2 sensor (12) based on a cooling water temperature (TW) of the engine coolant. The temperature is estimated and detected, and the O2 sensor failure diagnosis means (23) is configured such that the cooling water temperature (TW) is equal to or lower than a first predetermined temperature (TW1) and the output power of the O2 sensor (12). When (V) is a value to be detected by the active state, there is a first feature in that the diagnosis and the failure to the O2 sensor (12) occurs.

  The O2 sensor (12) includes a nonvolatile memory (24) that stores a diagnosed flag (25) that is established when the failure diagnosis is completed, and the O2 sensor failure diagnosis means (23) includes the nonvolatile memory (24). The second feature is that failure diagnosis of the O2 sensor (12) is not executed while the diagnosed flag (25) is stored.

  The O2 sensor failure diagnosing means (20) sets the diagnosed flag (25) when the coolant temperature (TW) exceeds a second predetermined temperature (TW) greater than the first predetermined value (TW1). A third feature is that the data is erased from the nonvolatile memory (24).

  Further, the O2 sensor (12) is pulled up to a set voltage (5V), so that it outputs a value close to the set voltage (5V) in the inactive state and close to 0V when in the active state. The O2 sensor failure diagnosis means (23) is configured to output a value when the voltage output (V) of the O2 sensor (12) is close to 0V during the failure diagnosis. There is a fourth feature in diagnosing the failure of (12).

  According to the first feature, the O2 sensor temperature estimation means estimates and detects the temperature of the O2 sensor based on the cooling water temperature of the engine cooling water, and the O2 sensor failure diagnosis means determines that the cooling water temperature is equal to or lower than the first predetermined temperature. When the output voltage of the O2 sensor is a value detected in the activated state, it is diagnosed that the O2 sensor has failed. Therefore, based on the engine coolant temperature, the activation / deactivation state of the O2 sensor is determined. Estimation and O2 sensor failure diagnosis can be performed. Thus, battery power is not consumed while the engine is stopped, as compared with a method in which the control unit or the like is continuously driven even after the engine is stopped in order to estimate the temperature of the O2 sensor based on the elapsed time after the engine is stopped. .

  According to the second feature, the non-volatile memory that stores the diagnosed flag that is established when the failure diagnosis of the O2 sensor is completed is provided, and the O2 sensor failure diagnosing means is O2 while the diagnosed flag is stored in the nonvolatile memory. Since the sensor failure diagnosis is not executed, even if the engine stop / start is repeated for a short time after the failure diagnosis is completed, the failure diagnosis may be executed each time the engine is stopped / started. This eliminates the burden on the control device.

  According to the third feature, the O2 sensor failure diagnosing unit deletes the diagnosed flag from the nonvolatile memory when the cooling water temperature exceeds the second predetermined temperature that is higher than the first predetermined value, so that the cooling water temperature becomes sufficiently high. In such a case, it is possible to execute the failure diagnosis at the next engine start, assuming that a certain amount of time has passed since the engine start and that the second failure diagnosis is effective.

  According to the fourth feature, the O2 sensor is pulled up to a set voltage, so that a value close to the set voltage is output in the inactive state, and a value close to 0 V is output in the active state. The O2 sensor failure diagnosis means diagnoses a failure of the O2 sensor when the voltage output of the O2 sensor is close to 0V at the time of failure diagnosis, and therefore detects a ground short of the O2 sensor as a failure. Can do.

It is a functional block diagram which shows the structure of the failure diagnostic apparatus of O2 sensor which concerns on one Embodiment of this invention. It is a time chart which shows the flow of O2 sensor failure diagnosis control. It is a flowchart which shows the procedure of O2 sensor failure diagnosis control.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing the configuration of an O2 sensor failure diagnosis apparatus according to an embodiment of the present invention. The control unit 20 can be incorporated in an ECU of a vehicle that uses an engine as a drive source. The control unit 20 includes an IG switch 10 that turns on the vehicle when the engine is started, a water temperature sensor 11 that detects the temperature of the engine coolant, and an O2 sensor that is attached to the exhaust pipe of the engine and detects the oxygen concentration of the combustion gas. 12 are connected to each other.

  The IG switch 10 has a function of supplying electric power of the vehicle-mounted battery to electronic components of each part of the vehicle body in addition to the ECU including the control unit 20 by being switched from off to on when the engine is started. The water temperature sensor 11 is a temperature sensor that detects the temperature of cooling water passing through the inside of a cylinder of the engine.

  The O2 sensor 12 is an oxygen sensor using an element such as zirconia, and is attached to the downstream side of the exhaust pipe catalyst device. The oxygen concentration can be detected only when the O2 sensor 12 is heated to a predetermined temperature (for example, 300 degrees) or more and activated. In this embodiment, when the temperature is sufficiently lower than the activation temperature, it is pulled up so that a set voltage (for example, 5V) is output, and the output voltage gradually decreases as the temperature rises. When the temperature rises to the activation temperature, it is set to be lower than the activation determination voltage. Thereby, based on the output voltage of the O2 sensor 12, it can be speculatively detected that the activated state has been reached.

  According to the above setting, when the output voltage is greatly reduced despite the temperature of the O2 sensor 12 being sufficiently lower than the activation temperature, there is some failure (particularly, a ground short) in the O2 sensor. It is possible to diagnose that it has occurred.

  In the present embodiment, the temperature of the O2 sensor 12 is estimated and detected based on the sensor output of the water temperature sensor 11. Here, the engine coolant is cooled by a radiator with an electric fan, and the temperature is controlled so as not to exceed an upper limit value (for example, 100 degrees). Therefore, particularly in a high temperature range, the temperature detected by the water temperature sensor 11 and the actual temperature of the O2 sensor 12 are greatly different from each other, but the manner in which the temperature rises after starting the engine from the cold state is correlated with each other. The temperature of the O2 sensor 12 is estimated and detected based on this correlation.

  In the present embodiment, in addition to the output of the water temperature sensor 11 and the output of the O2 sensor 12, a failure diagnosis of the O2 sensor 12 is executed in consideration of the elapsed time since the IG switch 10 is turned on.

  The control unit 20 includes a timer 21 that measures an elapsed time since turning on the IG switch 10, an O2 sensor temperature estimation unit 22 that estimates the temperature of the O2 sensor 12 based on the output of the water temperature sensor 11, and the water temperature sensor 11. The O2 sensor failure diagnosis means 23 for diagnosing the failure of the O2 sensor based on the output of the non-volatile memory 24 and the nonvolatile memory 24 for storing the diagnosed flag 25 are included.

  The O2 sensor failure diagnosis means 23 performs failure diagnosis of the O2 sensor 12 in consideration of the output of the water temperature sensor 11 and the output of the O2 sensor 12 when the elapsed time after turning on the IG switch 10 reaches a predetermined value. Run. The O2 sensor temperature estimating means 22 estimates and detects the temperature of the O2 sensor 12 based on the correlation between the output of the water temperature sensor 11 and the temperature of the O2 sensor 12 obtained in advance through experiments or the like. The O2 sensor failure diagnosing means 23 establishes a diagnosed flag 25 when the failure diagnosis of whether the O2 sensor 12 is normal or abnormal is completed, and stores the diagnosed flag 25 in the nonvolatile memory 24 that can retain the memory even when the power is turned off. save.

  FIG. 2 is a time chart showing the flow of O2 sensor failure diagnosis. The upper graph shows the relationship between the output voltage V of the O2 sensor 12 and the cooling water temperature TW detected by the water temperature sensor 11. In the lower graph, in order from the top, the IG switch 10 is turned on / off, the determination timer is activated, the diagnosis flag 25 is established / not established, the failure determination flag is established / not established, and the normal determination flag is established / Indicates a failure condition.

  At time t = 0, the engine is in a cold state in which sufficient time has elapsed since the previous engine stop. At time t1, when the IG switch 10 is turned on to start the engine, the power of the in-vehicle battery is supplied to an electric power device such as an ECU. Along with this, the output voltage V of the O2 sensor 12 indicates 5 V of the pulled-up set voltage.

  In the present embodiment, the engine is started immediately after the IG switch 10 is turned on, and a determination timer for measuring a predetermined time from time t1 is started. Next, at time t2 when the determination timer reaches a predetermined time, a failure diagnosis of the O2 sensor 12 is executed. In the example of this graph, the normal determination flag is established and the diagnosed flag 25 is established.

  The O2 sensor failure diagnosis means 23 outputs the output voltage V of the O2 sensor 12 below the activation determination voltage V1 on condition that the cooling water temperature TW is equal to or lower than the GND short detection upper limit water temperature TW1 as the first predetermined temperature at time t2. It is determined whether or not. Here, at time t2, since the cooling water temperature TW is equal to or lower than the GND short detection upper limit water temperature TW1 and the output voltage V exceeds the activation determination voltage V1, the O2 sensor 12 is determined to be normal. On the other hand, if the coolant temperature TW is equal to or lower than the GND short detection upper limit water temperature TW1 and the output of the O2 sensor 12 is equal to or lower than the activation determination voltage V1, it is determined that a ground short or the like has occurred in the O2 sensor 12. The failure determination flag is established instead of the normal determination flag.

  Next, in the example of this graph, the output of the O2 sensor 12 reaches the rich / lean determination voltage V2 at time t3. During engine operation, the oxygen concentration is estimated and detected by comparison with the rich / lean determination voltage V2.

  At subsequent time t4, the cooling water temperature TW reaches the determined flag reset water temperature TW2. As a result, the O2 sensor failure diagnosis unit 23 returns the diagnosed flag established at time t2 to not established, assuming that a sufficient time has elapsed since the failure diagnosis was performed at time t2. In the present embodiment, the cooling water temperature TW continues to increase after time t4, but since it is cooled by the radiator, it does not become higher than the preset upper limit value TW3.

  In the present embodiment, the engine is started immediately after the IG switch 10 is turned on at time t1, but, for example, there is a gap between when the IG switch 10 is turned on and when the engine is started. Even in this case, since the increase in the coolant temperature TW is only delayed, what is actually normal in the fault diagnosis is not misdiagnosed as abnormal.

  Further, when the engine is stopped with the O2 sensor 12 activated, the temperature of the O2 sensor 12 gradually decreases and shifts from the activated state to the deactivated state at a certain point. The time until the O2 sensor 12 shifts to the inactivated state is set to be shorter than the time until the cooling water temperature TW decreases from the determined flag reset water temperature TW2 to the GND short detection upper limit water temperature TW1.

  FIG. 3 is a flowchart showing a procedure of O2 sensor failure diagnosis control. This flowchart corresponds to the time chart shown in FIG.

  First, in step S1, the IG switch 10 is switched on, and in step S2, a timer 21 constituting a determination timer is started. Next, in step S3, the determination timer reaches a predetermined time, the engine coolant temperature TW is detected in step S4, and the output voltage V of the O2 sensor 12 is detected in step S5.

  In step S6, it is determined whether the engine coolant temperature TW is equal to or lower than a first predetermined temperature (GND short detection upper limit water temperature) TW1, and if an affirmative determination is made, the process proceeds to step S7. In step S7, it is determined whether or not the output voltage V of the O2 sensor 12 is equal to or lower than a predetermined voltage (activation determination voltage) V1, and if an affirmative determination is made, the process proceeds to step S8.

  In step S8, the failure determination flag is switched on. At the same time, the diagnosed flag 25 is established and stored in the nonvolatile memory 24. When the failure determination flag is switched on, a failure of the O2 sensor 12 can be notified by displaying it on the indicator of the meter device.

  If a negative determination is made in step S6, the series of control is terminated as it is, and if a negative determination is made in step S7, step S8 is skipped and the process proceeds to step S9.

  In step S9, it is determined whether or not the engine coolant temperature TW has exceeded a second predetermined temperature (determined flag reset water temperature) TW2. If the determination is affirmative, the process proceeds to step S10. In step S10, the failure determination flag is reset, and at the same time, the diagnosed flag 25 is erased from the nonvolatile memory 24, and a series of control is terminated.

  The diagnosed flag 25 stored in the nonvolatile memory 24 by the above processing procedure is maintained in the stored state unless the engine coolant temperature TW exceeds the second predetermined temperature TW2. In other words, while the diagnosed flag 25 is stored in the nonvolatile memory 24, even if the power supply is repeatedly turned off / on due to engine stop / restart, the O2 sensor failure diagnosis is not repeated each time. The burden on the control unit 20 can be reduced.

  As described above, according to the failure diagnosis apparatus for an O2 sensor according to the present invention, the activation state / inactivation state of the O2 sensor can be estimated based on the engine coolant temperature, and the failure diagnosis of the O2 sensor can be executed. . Thereby, compared with the system which estimates and detects the temperature of the O2 sensor based on the elapsed time from the engine stop, it is possible to achieve an effect that battery power is not consumed while the engine is stopped.

  The structure of the O2 sensor and the set values of the activation temperature, the set values of the first predetermined temperature and the second predetermined temperature, the set values of the activation determination voltage V1 and the GND short detection upper limit water temperature V2, etc. are not limited to the above embodiment. However, various modifications are possible. The O2 sensor failure diagnosis apparatus according to the present invention can be applied to various work machines and the like in addition to a vehicle using an engine as a drive source.

  DESCRIPTION OF SYMBOLS 10 ... IG (ignition) switch, 11 ... Water temperature sensor, 12 ... O2 sensor, 20 ... Control part, 21 ... Timer, 22 ... O2 sensor temperature estimation means, 23 ... O2 sensor failure diagnostic means, 24 ... Non-volatile memory, 25 ... Diagnosed flag, TW ... cooling water temperature, TW1 ... first predetermined temperature, TW2 ... second predetermined temperature, V1 ... activation determination voltage, V2 ... GND short detection upper limit water temperature

Claims (4)

  1. An O2 sensor (12) that is activated above a predetermined temperature and measures the oxygen concentration of the combustion gas of the engine;
    O2 sensor temperature estimation means (22) for estimating and detecting the temperature of the O2 sensor (12);
    O2 sensor failure diagnosis means (23) for diagnosing a failure of the O2 sensor (12) based on the output voltage (V) of the O2 sensor (12) and the temperature estimated and detected by the O2 sensor temperature estimation means (22). In the O2 sensor failure diagnosis apparatus having
    The O2 sensor temperature estimation means (22) estimates and detects the temperature of the O2 sensor (12) based on the cooling water temperature (TW) of the engine cooling water,
    The O2 sensor failure diagnosis means (23) detects the cooling water temperature (TW) below a first predetermined temperature (TW1) and the output voltage (V) of the O2 sensor (12) in the activated state. If the value is a value, it diagnoses that a failure has occurred in the O2 sensor (12).
  2. A non-volatile memory (24) for storing a diagnosed flag (25) that is established when a failure diagnosis of the O2 sensor (12) is completed;
    The O2 sensor failure diagnosis means (23) does not execute failure diagnosis of the O2 sensor (12) while the diagnosed flag (25) is stored in the nonvolatile memory (24). Item 2. The O2 sensor failure diagnosis device according to Item 1.
  3.   When the cooling water temperature (TW) exceeds a second predetermined temperature (TW) greater than the first predetermined value (TW1), the O2 sensor failure diagnosis means (20) sets the diagnosed flag (25) to the nonvolatile memory. 3. The O2 sensor failure diagnosis apparatus according to claim 2, wherein the O2 sensor failure diagnosis apparatus is deleted from (24).
  4. When the O2 sensor (12) is pulled up to a set voltage (5V), the O2 sensor (12) outputs a value close to the set voltage (5V) in an inactive state, and a value close to 0V in an activated state. Configured to output,
    The O2 sensor failure diagnosis means (23) diagnoses a failure of the O2 sensor (12) when the voltage output (V) of the O2 sensor (12) is close to 0V during the failure diagnosis. A fault diagnosis apparatus for an O2 sensor according to any one of claims 1 to 3.
JP2014189978A 2014-09-18 2014-09-18 O2 sensor failure diagnosis device Active JP6112619B2 (en)

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Application Number Priority Date Filing Date Title
JP2014189978A JP6112619B2 (en) 2014-09-18 2014-09-18 O2 sensor failure diagnosis device
DE102015114108.6A DE102015114108A1 (en) 2014-09-18 2015-08-25 Diagnostic system of an oxygen sensor
FR1558758A FR3026142A1 (en) 2014-09-18 2015-09-17 OXYGEN SENSOR DIAGNOSTIC SYSTEM

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001004580A (en) * 1999-06-16 2001-01-12 Mazda Motor Corp Failure diagnostic apparatus for air-fuel ratio sensor
JP2007315926A (en) * 2006-05-26 2007-12-06 Ngk Spark Plug Co Ltd Gas sensor system and abnormality diagnosing method of same
JP2010019715A (en) * 2008-07-11 2010-01-28 Ngk Spark Plug Co Ltd Diagnosis method of waste time delay deterioration of gas sensor, and diagnosis device of waste time delay deterioration of gas sensor
JP2010256233A (en) * 2009-04-27 2010-11-11 Denso Corp Sensor controller and sensor unit
JP2012251435A (en) * 2011-05-31 2012-12-20 Honda Motor Co Ltd Abnormality determination device of air-fuel ratio sensor
JP2012251795A (en) * 2011-05-31 2012-12-20 Yamaha Motor Co Ltd Activity determination system of oxygen sensor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001004580A (en) * 1999-06-16 2001-01-12 Mazda Motor Corp Failure diagnostic apparatus for air-fuel ratio sensor
JP2007315926A (en) * 2006-05-26 2007-12-06 Ngk Spark Plug Co Ltd Gas sensor system and abnormality diagnosing method of same
JP2010019715A (en) * 2008-07-11 2010-01-28 Ngk Spark Plug Co Ltd Diagnosis method of waste time delay deterioration of gas sensor, and diagnosis device of waste time delay deterioration of gas sensor
JP2010256233A (en) * 2009-04-27 2010-11-11 Denso Corp Sensor controller and sensor unit
JP2012251435A (en) * 2011-05-31 2012-12-20 Honda Motor Co Ltd Abnormality determination device of air-fuel ratio sensor
JP2012251795A (en) * 2011-05-31 2012-12-20 Yamaha Motor Co Ltd Activity determination system of oxygen sensor

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JP6112619B2 (en) 2017-04-12
DE102015114108A1 (en) 2016-03-24

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