KR20170039497A

KR20170039497A - System and Method for checking error of Fuel Tank Pressure Sensor

Info

Publication number: KR20170039497A
Application number: KR1020150138707A
Authority: KR
Inventors: 이민웅
Original assignee: 주식회사 현대케피코
Priority date: 2015-10-01
Filing date: 2015-10-01
Publication date: 2017-04-11

Abstract

A fault diagnosis system for a fuel tank pressure sensor is provided. The fault diagnosis system comprises an arithmetic logic for calculating a difference between a first pressure value measured by a fuel tank pressure sensor at a point of time when a canister close valve is closed with a duty of a purge valve adjusted to a specific duty in accordance with a duty adjustment command during the running of a vehicle and a second pressure value measured by the fuel tank pressure sensor after a predetermined time elapses from the closing point of time and calculating a slope value representing a rate of change of time with respect to the difference value, and a diagnosis logic for diagnosing whether or not the fuel tank pressure sensor is faulty based on a comparison result obtained by comparing the slope value and a preset threshold value. The present invention intends to provide a fault diagnosis system and method for a fuel tank pressure sensor for detecting change of characteristics of FTPS due to aging and foreign matters and slow transition errors in accordance with the same.

Description

FIELD OF THE INVENTION The present invention relates to a fuel tank pressure sensor,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a fault diagnosis system and method for a fuel tank pressure sensor, and more particularly, to a fault diagnosis system and a method for a fuel tank pressure sensor for diagnosing a fault according to a characteristic change of a fuel tank pressure sensor.

Generally, the automobile includes a fuel tank pressure sensor (FTPS) that generates an electrical signal after checking the air pressure in the fuel tank and the fuel tank, and a fuel tank pressure sensor A canister for collecting and discharging the fuel vapor generated in the fuel tank through the discharge pipe and discharging the fuel vapor to the atmosphere, and an engine electronic controller which is driven by the control signal of the engine electronic controller and is generated in the canister A purge control valve for controlling the fuel gas flowing through the supply pipe, and a surge tank which is generated at the purge control valve and uniformly distributes the fuel gas flowing through the discharge pipe to the engine and then flows into the engine. Here, the canister is a place for storing evaporative gas in the fuel tank, and is filled with activated carbon composed of carbon.

When the engine is driven, the fuel vapor generated in the fuel tank flows into the canister through the hose, and the canister in which the fuel vapor is introduced collects the fuel gas introduced by the solenoid valve and supplies the fuel gas to the purge control valve Flow.

The purge control valve is driven by a control signal of the engine electronic controller to introduce the introduced fuel gas into the surge tank through the exhaust port. The surge tank distributes the introduced fuel gas evenly and flows into the combustion chamber of the engine do.

On the other hand, the engine electronic controller performs an operation to check whether or not the purge system is leaking. If the canister shutoff valve is closed in the idle state of the engine and the entire purge system is sealed with the external atmospheric pressure, the inside of the fuel tank becomes a vacuum state, , The engine electronic controller controls and closes the purge control valve and checks the pressure change in the fuel tank.

The engine electronic controller calculates the pressure change to determine whether the purge system is leaking. At this time, the FTPS senses the pressure. Therefore, before the engine electronic controller checks the fuel leak detection operation, it is necessary to determine whether the pressure sensor is normal or not, that is, whether or not the FTPS is faulty in advance.

As described above, one of the components for detecting the abnormality of the purge system is the FTPS for sensing the pressure in the fuel tank, and the pressure sensor is composed of a diaphragm which is a normal sensor element. The pressure in the fuel tank acts in the upper direction of the diaphragm and the atmospheric pressure acts in the opposite direction.

This deflection of the diaphragm is sensed by the pressure difference. For example, when the pressure in the fuel tank is normally atmospheric pressure, the pressure sensor outputs a sensing signal of 2.5 V, outputs a sensing signal of 2.5 V or less in the case of a negative pressure, and a sensing signal of 2.5 V or more in the case of pressure.

The conventional method for the failure of the FTPS is performed through the following process.

The detection signal of the FTPS is usually in the range of 0V to 5V. When the 5V or 12V supply line of the FTPS is short-circuited, the engine electronic controller inputs the detection signal of the 5V pressure sensor. A pressure sensor signal of 0V is input.

Normally, a detection signal in the range of 0 V - 5 V is used as a valid value in the range of 0.3 V - 4.8 V. Thus, if a detection signal exceeding 4.8V or less than 0.3V is input to the engine electronic controller for a predetermined time (typically 10 seconds), the engine electronic controller determines the electrical error of the FTPS. The detection signal determined as an electrical error is a failure signal (Stuck Signal) and is used as a basis for determining whether or not the FTPS is stuck.

However, the engine electronic controller detects the leakage in the fuel tank, and as a precondition, the pressure in the fuel tank is set to about -11 hPa to 4 hPa or less. However, in a situation outside this condition (for example, The fuel tank system can not accurately determine the leak of the fuel tank system as well as the sticking of the FTPS by only the failure signal (Stuck Signal) in the case where the fuel tank is aged and the contact is poor or the pressure value is constantly maintained in the range of 9 to 12 hPa.

In addition, the aging and foreign matter of the FTPS causes a change in the sensing characteristic, for example, it is difficult to detect the pressure change in the fuel tank quickly, and it is difficult to detect the error due to the change in the sensing characteristic such as the slow transition error.

It is therefore an object of the present invention to provide a fault diagnosis system and method for a fuel tank pressure sensor for detecting changes in characteristics of FTPS due to aging and foreign matter and thus slow transition errors.

According to an aspect of the present invention, there is provided a fault diagnosis system for a fuel tank pressure sensor, the system comprising: a canister closing valve Calculates a difference between a first pressure value measured by the fuel tank pressure sensor and a second pressure value measured by the fuel tank pressure sensor at a point of time when a predetermined time has elapsed from the closing point of time Arithmetic logic for calculating a slope value representing a rate of change of time with respect to the difference value; And diagnosis logic for diagnosing whether the fuel tank pressure sensor is malfunctioning based on a comparison result obtained by comparing the slope value with a preset threshold value.

According to another aspect of the present invention, there is provided a method of diagnosing a fuel tank pressure sensor, the method comprising: closing a canister close valve in a state where the diagnostic logic adjusts the duty of the purge valve to a specific duty during driving of the vehicle; The fuel tank pressure sensor measures the first pressure value of the fuel tank at the time when the canister closing valve is closed and the second pressure value is measured at a point of time after the closing time ; Wherein the arithmetic logic, under control of the diagnostic logic, comprises: calculating a slope value representing a rate of change of time with respect to a difference value between the first pressure value and the second pressure value; And diagnosing logic of the fuel tank pressure sensor based on a result of comparison between the slope value and a preset threshold value.

According to the present invention, it is possible to perform a precise fault diagnosis on the fuel tank pressure sensor by diagnosing failures associated with changes in characteristics of FTPS as well as stuck errors and slow transition errors due to such characteristic changes.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram schematically showing the entire configuration of an engine control apparatus to which a fault diagnosis system for a fuel tank pressure sensor according to an embodiment of the present invention is applied. FIG.
2 is a block diagram of a failure diagnosis system of the fuel tank pressure sensor shown in Fig.
3 is a flowchart illustrating a method for diagnosing a failure of a fuel tank pressure sensor according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, advantages and features of the present invention and methods of achieving them will be apparent from the following detailed description of embodiments thereof taken in conjunction with the accompanying drawings.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. And effects of the present invention, the scope of the present invention is defined by the description of the claims.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising ", as used herein, unless the recited component, step, operation, and / Or added.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram schematically showing the entire configuration of an engine control apparatus to which a fault diagnosis system for a fuel tank pressure sensor according to an embodiment of the present invention is applied. FIG.

1, an intake pipe 11 is connected to an intake port of an engine 13, and a throttle valve 14 is installed in an intake pipe 11. As shown in Fig. The exhaust pipe 29 is connected to the exhaust port of the engine 13 and a lambda sensor 26 for measuring the degree of oxygen saturation contained in the exhaust gas burned by the engine 13 is installed in the exhaust pipe 29 .

A canister 17 is connected to the fuel tank 15 through a discharge pipe and the canister 17 is connected to the intake pipe 11 through a supply pipe 19 having a purge valve 18, A discharge pipe 21 having a Canister Close Valve (CCV) 20 is connected. A filter 22 is attached to the distal end of the discharge pipe 20.

The canister 17 temporarily stores evaporative gas generated in the fuel tank 15 and sucks the evaporative gas into the intake pipe 11 by a negative pressure during operation of the engine 13. [ Therefore, an evaporation path of the fuel gas is formed in the order of the fuel tank 15, the discharge pipe 16, the canister 17, the supply pipe 19 and the discharge pipe 21. [

A fuel level sensor 23 and a temperature sensor 24 for detecting a fuel temperature are provided as sensing means for sensing the amount of fuel remaining in the fuel tank 15. A fuel tank pressure sensor A pressure sensor (FTPS) 25 is installed.

Each of the sensors 23, 24, 25 and 26 is connected to an electronic control unit (hereinafter referred to as an ECU) 26 and the ECU 26 compares a measured value inputted from each of the sensors 23, 24, The ignition timing, and the idle air amount so as to optimally control the engine 13 to determine whether or not each component of the vehicle is faulty. That is, the presence or absence of abnormality of the FTPS 25 is determined in order to accurately diagnose the leakage of the fuel tank 15. Here, the process of diagnosing the leakage of the fuel tank 15 is a well-known technique, and a detailed description thereof will be omitted.

2 is a block diagram of the fault diagnosis system of the FTPS shown in FIG.

Referring to FIG. 2, the fault diagnosis system of the FTPS 25 according to the embodiment of the present invention detects the pressure of the fuel tank 15 until a predetermined time elapses at the time when the pressure value of the fuel tank 15 is stabilized (Or a slope value) with respect to the value, and diagnoses the failure of the FTPS 25 based on the analysis result obtained by analyzing the calculated time change rate (or slope value).

The time point at which the pressure value of the fuel tank 15 is stabilized may be a pressure value measured in a state in which the vehicle travels stably. Here, the state in which the vehicle stably travels means that the driving state of the engine 13 maintains the optimum state so that the vehicle does not start and the vehicle stably travels.

An accurate reference value is required for accurately determining the rate of change with respect to the pressure value of the fuel tank 15, (The first pressure value in claim 1).

The driving state of the engine 13 is closely related to various factors such as the fuel level, the current vehicle speed of the vehicle, the measured value measured by the lambda sensor 26 measuring the oxygen saturation contained in the exhaust gas, and the like.

The fault diagnosis system of the FTPS 25 according to an embodiment of the present invention analyzes various factors as described above and judges whether or not the driving state of the engine 13 satisfies the stabilization condition for driving in the optimum driving state do. Here, the stabilization condition may be interpreted as a condition for diagnosing the failure of the FTPS 25.

When the driving condition of the engine satisfies the stabilization condition, the canister closing valve (CCV) 20 is closed, the pressure value of the fuel tank 15 measured at the closing time is set as a reference, And the rate of change (slope value) of the value with respect to time is measured.

To diagnose the failure of the FTPS 25, the failure diagnosis system of the fuel FTPS 25 according to the embodiment of the present invention includes a fuel level sensor 23, a lambda sensor 26 A vehicle speed sensor 27, an I / G switch 28, and an electronic control unit (ECU) 30. Here, the electronic control unit (ECU) may be referred to as an engine control unit. 1, the vehicle speed sensor 27 and the I / G switch 28 are not shown.

The ECU 30 includes an arithmetic logic 31 and a diagnostic logic 33.

The arithmetic logic 31 starts the arithmetic operation in accordance with the operation instruction of the diagnosis logic 33. [

The arithmetic logic 31 determines whether or not the purge valve 18 is in a first duty state when the CCV 20 is closed when the duty of the purge valve 18 is adjusted to a specific duty, And receives a pressure value and a second pressure value measured by the FTPS 25 when a predetermined time has elapsed from the closed time point. The purge valve 18 forms an evaporation path for moving the evaporated gas in the fuel tank 15 into the cylinder in order to remove the evaporated gas in the fuel tank 15. In an embodiment of the present invention, For the purpose of diagnosing the failure of the fuel tank 15, a vapor path for intentionally forming a pressure change in the fuel tank 15 is formed.

The arithmetic logic 31 calculates a difference value between the first pressure value and the second pressure value and calculates a slope value indicating a rate of change of time with respect to the calculated difference value.

The diagnosis logic 33 has two operation modes consisting of a leak diagnosis mode of the fuel tank 15 and a failure diagnosis mode of the FTPS 25. [

In the failure diagnosis mode of the FTPS 25, the diagnosis logic 33 detects the fuel level sensor 23, the lambda sensor 26, the vehicle speed sensor 27 ) And I / G switching (28).

The diagnostic logic 33 uses the collected information to determine whether the driving condition of the engine satisfies the stabilization condition.

In detail, the diagnosis logic 33 analyzes the current fuel level of the fuel tank 15 transmitted from the fuel level sensor 23 and analyzes whether the current fuel level of the fuel tank 15 falls within a predetermined range . Here, the predetermined range is MIN-20 liters <fuel level <MAX-10 liters (L), MIN is the minimum fuel level required for driving the vehicle, and MAX is the maximum fuel level required for driving the vehicle .

If the current fuel level is less than MIN-20 liters (l), that is, if the fuel level in the fuel tank 15 is too small, it may happen that the pressure in the fuel tank 15 does not fall, It is difficult to measure the pressure change rate of the fuel tank 15 accurately. On the other hand, when the present fuel level is higher than MAX-10 liters (l), that is, when the fuel level in the fuel tank 15 is excessively large, since the fuel can contact the FTPS, It is difficult to measure accurately.

Further, the diagnosis logic 33 analyzes whether the current vehicle speed value of the vehicle transmitted from the vehicle speed sensor 27 is equal to or greater than a predetermined vehicle speed value. Here, the predetermined vehicle speed value may be 80 km / h.

The diagnosis logic 33 may also be configured to detect prior art oscillation and stuck error checking prior to diagnosing faults associated with changes in the characteristics of the FTPS 25 and slow transition errors due to such characteristics changes. . The oscillation error check is a process for determining whether the value measured by the FTPS 25 vibrates for a preset time (for example, 1 second) , It is determined that there is an error. In this case, since it is confirmed that there is an error in the conventional fault diagnosis, the fault diagnosis related to the characteristic change of the FTPS 25 and the slow transition error due to such characteristic change is not performed. Also, if an error is confirmed in the stuck error check, similarly, the failure diagnosis related to the characteristic change of the FTPS 25 and the slow transition error due to such characteristic change is not performed.

The diagnosis logic 33 judges whether or not a Close Loop Control (CLC) is possible in order to confirm the stabilization state of the engine. The diagnostic logic 33 determines whether the fuel injection quantity is properly adjusted based on the measured value of the lambda sensor 26 and whether the throttle valve 14 (or the manifold pressure sensor) ) Is determined to be constant. Although the MAP sensor is not shown in FIGS. 1 and 2, the diagnostic logic 33 may be configured to receive the measured value from the MAP sensor.

If the diagnosis logic 33 determines that the fuel level, the vehicle speed, the oscillation and the stuck error check, and the CLC availability are all satisfied, 15 to control the purge valve 18 to open the duty of the purge valve 18 to a specific duty. Here, the specific duty may be 50% to 100%.

The diagnostic logic 33 analyzes the measured value measured by the lambda sensor with the purge valve 18 adjusted to a specific duty to determine whether the measured value is stabilized.

Specifically, the diagnostic logic 33 analyzes whether the measured value of the lambda sensor 26 is maintained at a value within a predetermined range for a particular time, the specific time is 5 seconds, the predetermined range is 0.9 ≤ measurement value ≤1.1.

When the measured value of the lambda sensor 26 is analyzed, if the measured value is determined to be stable, the diagnostic logic 33 closes the CCV 20.

Simultaneously with the closing of the CCV 20 the diagnostic logic 33 directs the operation of the FTPS 25 and the FTPS 25 responds to the instructions of the diagnostic logic 33 at the time the CCV 20 is closed (First pressure value) of the fuel tank 15 measured and a pressure value (second pressure value) of the fuel tank 15 measured at a point of time when a predetermined time elapses from the closing point of time is calculated by the calculation logic 31 ).

Then, the arithmetic logic 31 calculates a difference value between the first pressure value and the second pressure value, calculates a slope value indicating a rate of change of time with respect to the calculated difference value, and outputs the result to the diagnosis logic 33).

The diagnosis logic 33 diagnoses the failure of the FTPS 25 based on a result of comparison between a slope value received from the arithmetic logic 31 and a predetermined threshold value. For example, if the slope value is greater than or equal to the threshold value, the FTPS 25 is determined to be normal, the mode is changed to the fuel tank leak diagnosis mode in the FTPS failure diagnosis mode, and the fuel tank leak diagnosis is started. On the other hand, if the slope value is smaller than the threshold value, it is possible to check the property change due to the aging of the FTPS 25 and the slow transition error, Proceed with action.

3 is a flowchart illustrating a method for diagnosing failure of an FTPS according to an embodiment of the present invention. To facilitate understanding of the description, reference is made to Figures 1 and 2 together. The contents overlapping with the description of FIG. 1 and FIG. 2 will be briefly described.

Referring to FIG. 3, first, in the diagnosis logic 33, a step of receiving an ON signal from the I / G switch 28 is advanced (S311). The diagnosis logic 33 determines that the vehicle is in the on-state when the on-signal is received.

Next, in the diagnosis logic 33, a step of checking the current fuel level in the fuel tank 15 is performed (S313). Specifically, it is determined whether or not the current fuel level in the fuel tank 15 belongs to the predetermined range. If the current fuel level is out of the preset range, the process returns to the previous step without proceeding to the next step. Herein, the predetermined range is MIN - 20 (liter (l) <fuel level <MAX - 10 liters (L), MIN is the minimum fuel level required for driving the vehicle, MAX is the maximum fuel Respectively.

Then, in the diagnosis logic 33, a step of determining whether the current diagnostic mode is the fuel tank leak diagnostic mode is advanced (S315). If the current diagnostic mode is the fuel tank leakage diagnostic mode, the process returns to the step S313 and remains in the standby state until the fuel tank leakage diagnostic mode is terminated.

Next, in the diagnosis logic 33, a step of checking the oscillation and the stuck error of the FTPS 25 proceeds (S317). If it is determined that the oscillation and the stuck error are normal, the fault diagnosis of the FTPS 25 is started. In a narrow sense, the fault diagnosis of the FTPS can be interpreted as starting from the step S317 onward, but interpreted in a broad sense, it can be interpreted as starting from the step S311.

Next, the diagnosis logic 33 proceeds to step S319 to determine whether the present vehicle speed value of the vehicle is equal to or greater than a predetermined vehicle speed value. If the current vehicle speed value of the vehicle is less than the preset vehicle speed value, the process returns to step S313 and executes the series of steps again. Here, the predetermined vehicle speed value may be 80 km / h.

If it is determined that the current vehicle speed value of the vehicle is equal to or greater than the preset vehicle speed value, a step of determining whether close loop control (CLC) is possible is performed (S321). The diagnostic logic 33 determines whether the fuel injection quantity is properly adjusted based on the measured value of the lambda sensor 26 and whether the throttle valve 14 (or the manifold pressure sensor) ) Is determined to be constant.

Then, in the diagnosis logic 33, if it is confirmed that the CLC is possible, a step of adjusting the duty of the purge valve 18 to a specific duty proceeds (S323). Here, the specific duty may be 50% to 100%.

Subsequently, in the diagnosis logic 33, when the duty of the purge valve 18 is adjusted to a specific duty, the step S325 of determining whether the lambda value of the lambda sensor 26 is in the stabilized state is advanced (S325 ). If the measured value of the lambda sensor 26 is maintained at a value within a predetermined range for a specific time, it is determined that the lambda value is in the stabilized state. Here, the specific time is 5 seconds, and the predetermined range may be 0.9? Measured value? 1.1. If the lambda value is less than 0.9, a situation may occur in which the vehicle may be turned off.

If the lambda value is out of the predetermined range, it is determined that the lambda value is in an unstable state, and the process returns to step S313 and the sequence step is executed again.

Then, in the diagnosis logic 33, if it is determined that the lambda value is stabilized, it is recognized that the driving state of the engine is in a stabilized state, and the step of closing the CCV 20 proceeds (S327).

Next, in the calculation logic 31, the first pressure value of the fuel tank measured by the FTPS 25 at the time when the CCV 20 is closed and the second pressure value of the fuel tank measured by the second The step of receiving a pressure value and calculating a slope value indicating a rate of change of time with respect to a difference value between the first pressure value and the second pressure value is performed (S329).

Next, in the arithmetic logic 31, a step of determining whether the slope value is smaller than a threshold value is performed (S331).

If the slope value is smaller than the threshold value, it is checked whether there is a characteristic change due to the aging of the FTPS 25 and a slow transition error therefrom, and the fuel tank leakage diagnosis is not performed (S333) 25 are replaced and repaired (S335).

On the other hand, if it is determined in step S331 that the slope value is equal to or larger than the threshold value, it is determined that the FTPS 25 is normal and fuel tank leakage diagnosis is started (S337).

As described above, by detecting the change in the characteristics of the FTPS 25 and the subsequent slow transition errors before starting the fuel tank leakage diagnosis, it is possible to accurately diagnose the failure due to the aging of the FTPS 25 and foreign matter adherence can do.

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, And various alternatives, modifications, and alterations can be made within the scope.

Therefore, the embodiments described in the present invention and the accompanying drawings are intended to illustrate rather than limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and accompanying drawings . The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

Claims

During the running of the vehicle, at the time when the duty of the purge valve is adjusted to a specific duty according to the duty adjustment command and the canister closing valve is closed, the first pressure value measured by the fuel tank pressure sensor, Computing logic for calculating a difference value between the second pressure values measured by the fuel tank pressure sensor at a point of time when a predetermined time elapses from the time point and calculating a slope value indicating a rate of change of time with respect to the difference value; And
A diagnosis logic for diagnosing whether or not the fuel tank pressure sensor is faulty based on a comparison result obtained by comparing the slope value with a preset threshold value
The fuel tank pressure sensor comprising:

2. The apparatus of claim 1,
Comprising: analyzing factors including a fuel level in a fuel tank, a current vehicle speed value of the vehicle, and a measured value of a lambda sensor that measures oxygen saturation of the exhaust gas, and based on the analyzed result of the factor, Wherein the fuel tank pressure sensor generates a command.

3. The method of claim 2,
It is analyzed whether the fuel level in the fuel tank belongs to a predetermined range,
The predetermined range may be,
MIN - 20 liters (l) <fuel level <MAX - 10 liters (l)
Here, the MIN is a minimum fuel level required for driving the vehicle, and the MAX is a maximum fuel level required for driving the vehicle.

3. The method of claim 2,
The controller determines whether the current vehicle speed value of the vehicle is greater than or equal to a preset vehicle speed value,
Wherein the predetermined vehicle speed value is 80 km / h.

3. The method of claim 2,
Analyzing whether the measured value of the lambda sensor is maintained at a value within a predetermined range for a specific time,
The predetermined time is 5 seconds, and the predetermined range is 0.9? Measured value? 1.1.

Closing the canister close valve when the diagnostic logic adjusts the duty of the purge valve to a specific duty while driving the vehicle;
The fuel tank pressure sensor measures the first pressure value of the fuel tank at the time when the canister closing valve is closed and the second pressure value is measured at a point of time after the closing time ;
Wherein the arithmetic logic, under control of the diagnostic logic, comprises: calculating a slope value representing a rate of change of time with respect to a difference value between the first pressure value and the second pressure value; And
Diagnosing whether the fuel tank pressure sensor is faulty based on a comparison result obtained by comparing the slope value with a predetermined threshold value;
And a fuel tank pressure sensor for detecting a failure of the fuel tank pressure sensor.

7. The method of claim 6, wherein closing the canister closing valve comprises:
Analyzing a factor including a fuel level in the fuel tank, a current vehicle speed value of the vehicle, and a measured value of the lambda sensor measuring the oxygen saturation of the exhaust gas; And
Closing the canister closing valve based on the analysis result of analyzing the factor
Wherein the fuel tank pressure sensor includes a plurality of fuel pressure sensors.

8. The method of claim 7, wherein analyzing the factor comprises:
And analyzing whether the fuel level in the fuel tank belongs to a predetermined range,
The predetermined range is MIN - 20 (liter: l) <fuel level <MAX - 10 (liter: l), MIN is the minimum fuel level required for driving the vehicle, and MAX is the maximum fuel level required for driving the vehicle Wherein said fuel tank pressure sensor is a fuel tank pressure sensor.

8. The method of claim 7, wherein analyzing the factor comprises:
And analyzing whether the current vehicle speed value of the vehicle is greater than or equal to a predetermined vehicle speed value, wherein the predetermined vehicle speed value is 80 km / h.

8. The method of claim 7, wherein analyzing the factor comprises:
Analyzing whether the measured value of the lambda sensor is maintained at a value within a predetermined range for a specific time period, wherein the specific time is 5 seconds, and the predetermined range is 0.9? Measured value? A method of diagnosing a failure of a fuel tank pressure sensor.