KR20140121636A - Method and apparatus for diagnosing pressure switch of vehicle - Google Patents

Method and apparatus for diagnosing pressure switch of vehicle Download PDF

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Publication number
KR20140121636A
KR20140121636A KR20130038112A KR20130038112A KR20140121636A KR 20140121636 A KR20140121636 A KR 20140121636A KR 20130038112 A KR20130038112 A KR 20130038112A KR 20130038112 A KR20130038112 A KR 20130038112A KR 20140121636 A KR20140121636 A KR 20140121636A
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KR
South Korea
Prior art keywords
fuel
fuel pressure
pressure sensor
diagnosis
canister
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Application number
KR20130038112A
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Korean (ko)
Inventor
김한신
Original Assignee
콘티넨탈 오토모티브 시스템 주식회사
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Priority to KR20130038112A priority Critical patent/KR20140121636A/en
Publication of KR20140121636A publication Critical patent/KR20140121636A/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
    • F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
    • F02M25/0809—Judging failure of purge control system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D2041/224—Diagnosis of the fuel system
    • F02D2041/225—Leakage detection
    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Abstract

Disclosed are a method and an apparatus for diagnosing a fuel leakage in a vehicle. According to the present invention, after an engine is forcibly driven to diagnose the fuel leakage, a canister shutoff valve is controlled to be closed when a predefined diagnosis condition of a failure in a fuel pressure sensor is satisfied before a purge valve is controlled to be opened. After the canister shutoff valve is controlled to be closed, a fuel pressure variation is derived based on a predefined reference value and information on the fuel pressure of the fuel pressure sensor, wherein the information on the fuel pressure of the fuel pressure sensor is received for a predetermined time at a predefined cycle. When the derived fuel pressure variation is maintained for a predetermined allowable time equal to or greater than a predetermined allowable value, the failure in the fuel pressure sensor is determined to be caused by a noise component. Therefore, the cause of the failure in the fuel pressure sensor can be accurately diagnosed to improve the reliability of a result from the diagnosis of the fuel leakage.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and an apparatus for diagnosing fuel leakage in a vehicle,

The present invention relates to a method and an apparatus for diagnosing a fuel leak of a vehicle, and more particularly, to a method and an apparatus for accurately identifying a cause of a failure of a fuel pressure sensor during a fuel leak diagnosis using atmospheric pressure.

In recent years, exhaust gas regulations for automobiles have been strictly applied globally in the North American market. Regulations have been imposed on vehicles operating in North America such that the function of monitoring the fuel system leaks is essential to the engine control system (OBD-II).

This is to minimize the air pollution by preventing the evaporated fuel from being discharged into the atmosphere by lighting the warning lamp when leakage of the evaporative gas occurs in the fuel system leakage in the field.

In the conventional leak diagnosis of the fuel tank during engine stop, the leakage in the fuel tank is detected based on the change of the fuel pressure in the fuel tank which is reduced through the control of the purge valve after forming into the atmospheric pressure in the fuel tank through the control of the canister shutoff valve and the purge valve Execute the diagnosis.

That is, when the fuel pressure of the fuel tank reaches a predefined predetermined value through the control of the purge valve, a fuel pressure switch installed at a predetermined position in the fuel tank is connected to generate a fuel pressure switching connection signal, The fuel leak diagnosis in the fuel tank is executed based on whether or not the connection signal is received, the reception time, and the like.

However, there is no logic that can accurately identify the cause of failure of the fuel pressure sensor that accurately diagnoses the fuel pressure, which is one of the important factors in diagnosing the fuel leak.

Therefore, there is a need for a separate device and logic that can accurately determine the error of the fuel pressure sensor due to the noise supplied from the outside, accurately identify the cause of the failure of the fuel pressure sensor, and improve the reliability of the fuel leak diagnosis result .

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a fuel pressure sensor that satisfies diagnostic conditions for diagnosing a failure of a fuel pressure sensor, A fuel pressure sensor for detecting a failure of the fuel pressure sensor, and a fuel pressure sensor for detecting a failure of the fuel pressure sensor based on the fuel pressure change amount of the fuel tank received after the canister shutoff valve is closed. The fuel leakage diagnosis result is fundamentally increased in reliability.

It is another object of the present invention to provide an apparatus and method for diagnosing a fuel leak in a vehicle that improves a fixing error of a canister shutoff valve and a purge valve based on a fuel pressure change received when a fuel pressure sensor is normally determined, It is possible to improve the reliability of the fuel leak diagnosis result by executing the fault diagnosis of the purge valve.

According to a first aspect of the present invention, there is provided a fuel leak diagnosis method for a vehicle,

1. A method for diagnosing a fuel leak in a diagnostic control unit that executes fuel leak diagnosis in a fuel tank based on a fuel pressure change in a fuel tank of a fuel pressure sensor which is varied by controlling a canister shutoff valve and a purge valve,

A first step of closing the canister shutoff valve when the diagnosis control unit satisfies a predetermined fuel leak diagnosis condition and satisfies a failure diagnosis condition of a predefined fuel pressure sensor;

A fuel pressure sensor for sensing a fuel pressure signal for a predetermined period of time which is supplied from the fuel pressure sensor for a preset period and deriving a fuel pressure variation based on a difference between the received fuel pressure signal value and a predefined reference value, And a second step of determining that the predefined tolerance range is a failure of the fuel pressure sensor due to the noise component if the predefined tolerance is satisfied for a predetermined allowable time.

Preferably, the fuel pressure sensor failure diagnosis condition includes:

At least one of a stopping time of the vehicle before the control of opening the purge valve after the forced energization of the engine and a predetermined angular speed of less than a predetermined value, Or more.

Preferably, the allowable value of the second step is set to ± 10 hPa.

Preferably, the allowable time of the second step is set to 2 seconds to 10 seconds.

Preferably,

If the derived fuel pressure variation amount is not maintained for the predefined tolerance time beyond the predefined tolerance value and the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shutoff valve satisfies the predetermined first judgment reference range , Determining that the purge valve is a fixing error, and determining that the fuel pressure sensor is normal.

Preferably, the normal determination of the fuel pressure sensor includes:

It is determined that there is no error of the fuel pressure sensor due to the fixing error of the fuel pressure sensor and the noise component.

Preferably, the first determination reference value includes

-4 or more and -10 hPa or less.

Preferably,

When the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shut-off valve does not satisfy the predetermined first judgment reference range, the fuel pressure reduction amount of the fuel tank which decreases due to the closing control of the canister shut- And determining that the fuel pressure sensor is normal if the determination reference range is not satisfied.

Preferably, the second determination reference value is a value

-1 hPa or more and +1 hPa or less.

Preferably,

And a fuel leakage diagnosis step of performing a fuel leak diagnosis in the fuel tank if the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shutoff valve satisfies a predetermined second judgment reference range.

Preferably, the fuel leakage diagnosis step includes:

And a failure diagnosis of the canister shutoff valve is performed by using a separate device in case of a large-scale fuel leak as a result of the fuel leak diagnosis.

Preferably, the fuel leakage diagnosis step includes:

And the purge valve and the canister shut-off valve are determined to be normal when the fuel leak diagnosis is not a large-scale fuel leak.

According to a second aspect of the present invention, there is provided an apparatus for diagnosing fuel leakage of a vehicle,

And a diagnosis control section for executing a fuel leak diagnosis of the fuel tank in accordance with the fuel pressure change in the fuel tank of the fuel pressure sensor which is varied by controlling the canister shutoff valve and the purge valve.

Wherein the diagnosis control unit comprises:

Control of opening of purge valve after engine forced drive for diagnosis of fuel leakage If cancellation control of canister shutoff valve is satisfied if predefined fuel pressure sensor fault diagnosis condition is satisfied,

The predetermined time period after the closing control of the canister shut-off valve is set. The fuel pressure change amount is derived based on the fuel pressure of the received fuel pressure sensor and the predetermined reference value, and based on the derived fuel pressure change amount, And to perform a fault diagnosis of the power supply.

Preferably, the failure diagnosis of the fuel pressure sensor due to the noise component,

And that the fuel pressure sensor failure is caused by the noise component when the fuel pressure change amount is maintained for a predetermined allowable time that is equal to or larger than the predefined tolerance value.

As described above, the method and apparatus for diagnosing fuel leakage of a vehicle according to the embodiment of the present invention satisfy the diagnostic conditions of the fuel pressure sensor previously defined before the control of the opening of the purge valve after the forced energization of the engine for fuel leak diagnosis The canister shutoff valve is closed and the fuel pressure variation amount is derived based on the fuel pressure of the fuel pressure sensor which is received at the predetermined period after a predetermined period after the closing control of the canister shutoff valve and a predetermined reference value, If it is judged that the fuel pressure sensor is faulty due to the noise component if it is maintained over the predefined tolerance time above the predefined tolerance value, the cause of the failure of the fuel pressure sensor can be correctly identified, .

Further, according to the present invention, when the derived fuel pressure variation amount is not maintained for the predefined tolerance time beyond the predefined tolerance time, the fuel pressure variation amount satisfies the predefined first judgment reference range and the second judgment reference range The fuel pressure sensor is judged to be normal, and if the fuel pressure sensor does not satisfy the second criterion reference range, the fuel leak diagnosis is executed and if the fuel leak diagnosis is a large-scale fuel leak, the error diagnosis for the canister shut- It is possible to judge whether the purge valve and the canister shutoff valve are faulty or not according to the result of the leak diagnosis, thereby improving the reliability of the fuel leak diagnosis result.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further understand the technical idea of the invention. And should not be construed as limiting.
1 is a diagram showing a configuration of an apparatus for diagnosing a fuel leak of a vehicle according to an embodiment of the present invention.
2 is a flowchart illustrating a fuel leak diagnosis process of a vehicle according to an embodiment of the present invention.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

1 is a view showing an apparatus for diagnosing a fuel leak of a vehicle according to an embodiment of the present invention. The fuel leakage diagnosis apparatus for a vehicle according to the embodiment of the present invention will be described by way of example only with reference to the fuel leak diagnosis apparatus shown in Fig.

The apparatus for diagnosing a fuel leak of a vehicle to which the embodiment of the present invention is applied is characterized in that after the engine is stopped, both the canister shutoff valve and the purge valve are controlled to open to form the fuel pressure of the fuel tank 30 at atmospheric pressure, And the fuel pressure of the fuel tank which is decreasing as the control is controlled by the set value is monitored to derive the fuel leakage and the fuel leakage size.

1, a fuel tank 10 for storing fuel of an automobile, a canister 11 connected to the fuel tank 10 by a duct to collect the evaporated gas generated in the fuel tank 10, And a supply line 15 for supplying evaporative gas of the canister 11 to the engine 13 of the automobile.

A shut-off valve (16) for selectively opening and closing the connection between the canister (11) and the outside air to diagnose fuel leakage; A purge valve 17 disposed on the supply conduit 15 for controlling the amount of evaporative gas supplied from the canister 11 to the engine 13; And a diagnosis for diagnosing whether or not the fuel tank has leaked in the fuel tank based on a change in the fuel pressure inputted from the fuel pressure sensor (14) in the fuel tank (10) by controlling the canister shutoff valve (16) and the purge valve And a control unit 19.

The diagnostic control unit 19 may be integrally formed with the engine control unit (ECU), and may be provided separately from the engine control unit. If the engine control unit 19 is separately provided, The fuel pressure in the fuel tank supplied from the fuel pressure sensor 14 in the fuel tank during the fuel leak diagnosis is supplied to the engine control unit (ECU) to perform the fuel leak diagnosis by waking up the control unit (ECU) .

In the embodiment of the present invention, one example in which the diagnosis control unit 19 is formed integrally with the engine control unit will be described.

Although the fuel leakage diagnosis system of the embodiment includes the canister 11, the fuel leakage detection method of the present invention can be applied even if the fuel leakage diagnosis system does not include the canister 11. In this case, It can be interposed at any position where it is possible to select whether or not to block the outside air on the fuel leak diagnosis system.

On the other hand, the fuel leak diagnosis condition is that the fuel leak diagnosis related components such as the communication line, the fuel pressure switch, and the exhaust temperature sensor are all normal, the battery voltage is within a predetermined range (10 V or more and 16 V or less) Is set to a condition existing within a preset allowable range (10% or more and 80% or less).

Here, the fuel leak diagnosis condition is a result value obtained through a number of experiments by the manufacturer, and is stored in advance in the diagnosis control unit 19 as a table value.

The diagnosis control unit 19 controls the opening and closing of the canister shutoff valve 16 and the purge valve 18 to set the fuel pressure of the fuel tank 10 at atmospheric pressure. The canister closing valve 16 and the purge valve 17 are closed and the fuel leak is diagnosed based on the fuel pressure of the fuel pressure sensor 14 which varies in accordance with the opening control of the purge valve 17 .

However, before the purge valve is controlled to be opened after the forced energization of the engine, the diagnostic control unit 19 diagnoses the failure of the fuel pressure sensor by the noise component when the diagnostic condition of the fuel pressure sensor by the predefined noise component is satisfied .

Here, the fuel pressure sensor failure diagnosis condition based on the noise component is a low-speed performance in which the stopping time of the vehicle is at a predetermined speed (30 km / h) or more at a predetermined value (2 seconds) or more and the rotational angular velocity And a predetermined angular velocity (15 mm / sec) or less.

When the fuel pressure sensor fault diagnosis condition based on the noise component is satisfied, the diagnosis control unit 19 sets the canister shut-off valve 16 at a predetermined period that is supplied from the fuel pressure sensor 14 after closing the canister shut- And the fuel pressure variation derived from the difference between the received fuel pressure signal value and the predefined reference value, and the derived fuel pressure variation amount is equal to or greater than the predefined tolerance range (-10 hPa to +10 hPa) (2 to 10 seconds), it is judged that the fuel pressure sensor is faulty due to the noise component.

When the derived fuel pressure variation amount is not maintained for a predetermined allowable time or more, the diagnosis control unit 19 determines that the fuel pressure reduction amount of the fuel tank, which is reduced due to the closing control of the canister shut- If the set first determination reference value (-4 or more and -10 hPa or less) is satisfied, it is determined that the purge valve is stuck and the fuel pressure sensor is determined to be normal.

Here, the steady state of the fuel pressure sensor means that there is no error of the fuel pressure sensor due to the fixing error of the fuel pressure sensor and the noise component.

When the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shutoff valve 16 satisfies a predetermined second determination reference value (-1 or more and +1 hPa or less), the diagnosis control unit 19 determines that the fuel Perform fuel leak diagnosis in the tank.

And, the diagnosis of the canister shutoff valve 16 can be executed according to the diagnosis result of the fuel leakage and the leakage size in the fuel tank. For example, if large-scale fuel leakage is not determined as a result of the fuel leak diagnosis, the canister shutoff valve 16 is determined to be normal.

However, if it is determined that a large-scale fuel leak has occurred, the diagnosis of sticking error with respect to the canister shutoff valve 16 is performed through a separate diagnosis device after the engine stops. That is, it is determined whether or not the canister shut-off valve is fixed based on whether or not the canister shut-off valve is driven by repeatedly performing the maximum opening and the minimum closing with the magnitude of the information force capable of removing the foreign substance sandwiched by the canister shut- Thus, the stuck-at error of the canister shut-off valve is only implemented at the time of large-scale fuel leakage generation and is not implemented in the absence of small-scale fuel leakage and fuel leakage.

A fuel leak diagnosis process of a vehicle according to an embodiment of the present invention will now be described with reference to FIG.

The diagnosis control unit 19 controls both the canister shut-off valve 16 and the purge valve 17 to open and set the fuel pressure of the fuel tank 10 at atmospheric pressure when the pre- When the failure diagnosis execution condition of the fuel pressure sensor 14 due to noise after startup is satisfied, the canister shutoff valve 16 is closed (steps 101, 103, and 105).

The diagnostic control unit 19 receives the fuel pressure signal supplied from the fuel pressure sensor 14 and derives a fuel pressure variation amount with respect to the difference between the received fuel pressure signal value and a predefined reference value (steps 107 and 109).

Then, the diagnosis control unit 19 determines whether the derived fuel pressure variation amount satisfies a predetermined allowable range. If the derived fuel pressure variation amount satisfies the predefined allowable range, the diagnosis control unit 19 maintains (Steps 111 and 113).

If the fuel pressure variation amount satisfies the permissible range during the allowable time, the diagnosis control unit 19 determines in step 115 that the fuel pressure sensor is faulty due to the noise component through steps (111) and (113).

However, if the fuel pressure variation amount does not satisfy the allowable range through the steps (111) and (113), the diagnosis control unit 19 determines whether or not the amount of change in the fuel pressure, which is decreased due to the closing control of the canister shut- Is determined as a fixing error of the purge valve when the fuel pressure reduction amount satisfies the first determination reference range and the fuel pressure sensor is determined to be normal Step 119).

On the other hand, if the fuel pressure reduction amount does not satisfy the first determination reference range through step 117, the diagnosis control unit 19 determines whether the fuel pressure reduction amount satisfies a predetermined second determination reference range through step 121, If the resultant fuel pressure reduction amount satisfies the second determination reference range, it is determined that the fuel pressure sensor is normal (step 123).

If it is determined that the fuel pressure reduction amount does not satisfy the second determination reference range, the diagnosis control unit 19 performs the fuel leak diagnosis. If it is determined that the fuel leakage is large as a result of the fuel leak diagnosis, (Steps 125, 127, and 129).

On the other hand, if the large-scale fuel leakage is not determined, the diagnosis control unit 19 proceeds to step 131 to determine the purge valve and the canister shut-off valve as normal.

According to the embodiment of the present invention, when the fuel pressure sensor fault diagnosis condition defined before the opening control of the purge valve after the engine forced drive for the fuel leak diagnosis is satisfied, the canister shutoff valve is closed and the canister shutoff valve is closed The fuel pressure change amount is derived on the basis of the fuel pressure of the fuel pressure sensor and the predefined reference value, and the derived fuel pressure change amount is maintained for a predetermined allowable time equal to or greater than the predefined tolerance value It is possible to accurately identify the cause of the failure of the fuel pressure sensor and further improve the reliability of the fuel leak diagnosis result.

Further, according to the embodiment of the present invention, when the derived fuel pressure variation amount is not maintained for the predefined tolerance time exceeding the predefined tolerance value, the fuel pressure variation amount becomes larger than the predefined first judgment reference range and the second judgment reference range If the range is satisfied, the fuel pressure sensor is determined to be normal. If the fuel pressure sensor does not satisfy the second determination reference range, the fuel leak diagnosis is executed. If the fuel leak diagnosis is large fuel leak, the error diagnosis for the canister shut- Accordingly, it is possible to determine whether the purge valve and the canister shutoff valve are faulty or not according to the result of the fuel leak diagnosis, thereby further improving the reliability of the fuel leak diagnosis result.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Control of opening of purge valve after engine forced drive for diagnosis of fuel leakage If the fuel pressure sensor fault diagnosis condition defined before is satisfied, control of closing the canister shutoff valve and setting of the predetermined period after closing control of the canister shutoff valve When the fuel pressure change amount is derived based on the fuel pressure of the fuel pressure sensor and the predefined reference value and the derived fuel pressure variation amount is maintained for a predetermined allowable time exceeding the predefined tolerance value, A fuel leak diagnosis device for a vehicle capable of further improving the reliability of a fuel leak diagnosis result that can reliably diagnose a cause of a failure of the fuel pressure sensor by accurately determining a sensor failure, And methods in terms of accuracy and reliability of operation, and further performance Since a very large extent to bring a progress and, in addition there is sufficient potential for commercial or marketing of the vehicle to be applied can be apparently carried out in reality the rate if the invention in the industrial applicability.

Claims (14)

1. A method for diagnosing a fuel leak in a diagnostic control unit that executes fuel leak diagnosis in a fuel tank based on a fuel pressure change in a fuel tank of a fuel pressure sensor which is varied by controlling a canister shutoff valve and a purge valve,
A first step of closing the canister shutoff valve when the diagnosis control unit satisfies a predetermined fuel leak diagnosis condition and satisfies a failure diagnosis condition of a predefined fuel pressure sensor;
A fuel pressure sensor for sensing a fuel pressure signal for a predetermined period of time which is supplied from the fuel pressure sensor for a preset period and deriving a fuel pressure variation based on a difference between the received fuel pressure signal value and a predefined reference value, And a second step of determining that the predefined allowable range is a failure of the fuel pressure sensor due to a noise component if the predefined allowable time is satisfied for a predetermined allowable time. The fuel pressure sensor according to claim 1,
At least one of a stopping time of the vehicle before the control of opening the purge valve after the forced energization of the engine and a predetermined angular speed of less than a predetermined value, Or more of the fuel leakage amount. The method for diagnosing fuel leakage of a vehicle according to claim 2, wherein the tolerance of the second step is set to ± 10 hPa. 3. The method according to claim 2, wherein the allowable time of the second step is set to 2 to 10 seconds. 3. The method of claim 2,
If the derived fuel pressure variation amount is not maintained for the predefined tolerance time beyond the predefined tolerance value and the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shutoff valve satisfies the predetermined first judgment reference range And determining that the purge valve is stuck and that the fuel pressure sensor is determined to be normal. 6. The fuel pressure sensor according to claim 5,
The fuel pressure sensor is determined to be free from an error of the fuel pressure sensor due to a fixing error and a noise component of the fuel pressure sensor. 6. The method according to claim 5,
-4 > to -10 hPa. ≪ / RTI > 6. The method of claim 5,
When the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shut-off valve does not satisfy the predetermined first judgment reference range, the fuel pressure reduction amount of the fuel tank which decreases due to the closing control of the canister shut- Further comprising the step of determining that the fuel pressure sensor is normal if the determination criterion range is not satisfied. 9. The method of claim 8,
Wherein the fuel leakage amount is set to -1 hPa or more and +1 hPa or less. 9. The method of claim 8,
Further comprising a fuel leak diagnosis step of performing fuel leak diagnosis in the fuel tank if the fuel pressure reduction amount of the fuel tank which is reduced due to the closing control of the canister shutoff valve satisfies a predetermined second judgment reference range Fuel leakage diagnosis method. 11. The method of claim 10,
And diagnosing a fuel leak in the canister using a separate device in case of a large-scale fuel leak as a result of the fuel leakage diagnosis. 12. The method according to claim 11,
And determining that the purge valve and the canister shutoff valve are normal when the fuel leakage is not large-scale fuel leakage as a result of the fuel leakage diagnosis. And a diagnosis control section for executing a fuel leak diagnosis of the fuel tank in accordance with the fuel pressure change in the fuel tank of the fuel pressure sensor which is varied by controlling the canister shutoff valve and the purge valve.
Wherein the diagnosis control unit comprises:
Control of opening of purge valve after engine forced drive for diagnosis of fuel leakage If cancellation control of canister shutoff valve is satisfied if predefined fuel pressure sensor fault diagnosis condition is satisfied,
The predetermined time period after the closing control of the canister shut-off valve is set. The fuel pressure change amount is derived based on the fuel pressure of the received fuel pressure sensor and the predetermined reference value, and based on the derived fuel pressure change amount, And the fuel leakage diagnosis device is configured to execute the failure diagnosis of the vehicle. 14. The fuel pressure sensor failure diagnosis method according to claim 13,
And when the fuel pressure change amount is maintained for a predetermined allowable time that is equal to or greater than a predefined tolerance value, it is determined that the fuel pressure sensor fails due to the noise component.

KR20130038112A 2013-04-08 2013-04-08 Method and apparatus for diagnosing pressure switch of vehicle KR20140121636A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109357356A (en) * 2018-09-11 2019-02-19 珠海格力电器股份有限公司 Fault handling method and device, household appliance
CN112945374A (en) * 2019-07-10 2021-06-11 上海建工建材科技集团股份有限公司 Online fault detection method and system for concrete production equipment based on noise decibels

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109357356A (en) * 2018-09-11 2019-02-19 珠海格力电器股份有限公司 Fault handling method and device, household appliance
CN112945374A (en) * 2019-07-10 2021-06-11 上海建工建材科技集团股份有限公司 Online fault detection method and system for concrete production equipment based on noise decibels

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