KR20140051571A - Method for diagnosing stuck of evaporated fuelprocessing system using nature negative pressure - Google Patents

Method for diagnosing stuck of evaporated fuelprocessing system using nature negative pressure Download PDF

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Publication number
KR20140051571A
KR20140051571A KR1020120117757A KR20120117757A KR20140051571A KR 20140051571 A KR20140051571 A KR 20140051571A KR 1020120117757 A KR1020120117757 A KR 1020120117757A KR 20120117757 A KR20120117757 A KR 20120117757A KR 20140051571 A KR20140051571 A KR 20140051571A
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South Korea
Prior art keywords
negative pressure
natural negative
purge valve
pressure switch
diagnosing
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KR1020120117757A
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Korean (ko)
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KR101955634B1 (en
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김한신
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콘티넨탈 오토모티브 시스템 주식회사
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    • 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
    • F02M25/0827—Judging failure of purge control system by monitoring engine running conditions
    • 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 is a method for diagnosing a malfunction of an evaporated fuel processing device by using natural negative pressure. The method for diagnosing a malfunction of an evaporated fuel processing device by using natural negative pressure includes a step (a) of confirming whether conditions for generating the natural negative pressure in a fuel tank is satisfied; a step (b) of measuring operation time of a natural negative pressure switch while an engine is stopped and storing an external temperature; a step (d) of determining whether the operation time of the natural negative pressure switch exceeds a preset time while the engine is stopped; a step (e) of confirming whether the natural negative pressure switch is on or off; a step (f) of confirming whether maximum opening control of a purge valve starts; and a step (i) of determining whether a limit elapsed time according to a fuel level passes.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for diagnosing an evaporative fuel treatment apparatus using natural negative pressure,

The present invention relates to a method for diagnosing a failure of an evaporative fuel processing apparatus using a natural negative pressure, and more particularly, to a method of diagnosing a failure of an evaporative fuel processing apparatus using a natural negative pressure, And more particularly, to a fault diagnosis method for an evaporative fuel processing apparatus using a natural negative pressure capable of diagnosing a failure of a purge valve.

Background Art [0002] Generally, an internal combustion engine is a device that generates power by burning fuel and air in an engine, and an automobile utilizing the power of the internal combustion engine has a fuel tank for storing fuel for supplying the engine.

The fuel stored in the fuel tank may vary depending on the degree of volatility. However, as time elapses, the fuel evaporates to discharge the evaporated gas. When the evaporated gas is discharged to the outside air, Pollution due to discharge of unheated gas occurs.

Therefore, a recent automobile has an evaporative gas control system, that is, an evaporative fuel treatment device, which supplies evaporative gas generated in the fuel tank to the engine. This evaporative fuel treatment device is provided with a vapor passage (2), and the vaporized fuel adsorbed in the canister (3) is introduced into the canister (3) through the purge passage (4) under predetermined conditions, (Purged) the exhaust gas 6 to the outside. In the purge passage 4, a purge valve 7 is inserted and mounted as an opening and closing device for opening and closing the passage. A vent valve 8 for opening and closing the atmosphere introducing portion 12 is attached to the canister 3. The purge valve (7) and the vent valve (8) are used for diagnosing faults. The purge valve 7 and the vent solenoid valve 8 are connected to an engine control unit (hereinafter, referred to as "ECU") 11 as a control device. The purge valve 7 and the vent solenoid valve 8 are connected to the engine control unit 11 And the opening / closing control is performed in accordance with the control signal.

When the purge valve 7 is turned on, the purge passage 4 is opened, and when the purge valve 7 is turned off, the purge valve 7 is closed and the purge passage 4 is closed. The vent valve 8 opens the standby section 12 when the vent valve 8 is turned off and closes the standby section 12 when the vent valve 8 is turned on. In this evaporative fuel treatment apparatus, the purge valve 7 is normally turned on and the vent valve 8 is turned off. When the determination condition for determining the failure is established, the purge valve 7 is turned off to close the purge passage 4, and the vent valve 8 is turned on to close the standby inlet portion 12 And the inside of the fuel tank 1 is pressurized to about atmospheric pressure. In this state, the purge valve 7 is turned on, the purge passage 4 is opened, and the fuel tank 1 and the intake passage 6 are communicated with each other through the vapor passage 2 and the purge passage 4 And the internal pressure of the tank is reduced to the predetermined negative pressure P1 by the negative pressure action in the intake passage 6. [

The fuel tank 1 is provided with a fuel level sensor 9 as a fuel remaining amount detecting device, so that the remaining amount of fuel in the tank can be detected. The fuel tank 1 is provided with a pressure sensor 10 serving as a pressure detecting device and is capable of detecting a pressure detection value Pn which is a pressure in the tank. A fuel temperature sensor 20 as a fuel temperature detecting device is attached to the fuel tank 1 so that the fuel temperature in the tank can be detected. Detection information from the fuel level sensor 9, the pressure sensor 10 and the fuel temperature sensor 20 is sent to the engine control unit 11. [ A filler cap 16, which is freely attachable and detachable, is mounted on the filler port 17 of the fuel tank 1. The filler cap 16 is structured such that the filler cap 17 is hermetically closed when the filler cap 16 is normally mounted on the filler port 17 and is not introduced into the fuel tank 1 from the filler cap 17 have.

The evaporation fuel processing apparatus thus configured is provided with a failure diagnosis device 13 for detecting a leakage failure of the evaporation fuel processing apparatus in order to prevent the evaporation fuel from being discharged to the atmosphere due to a failure. 2, the failure diagnosis apparatus 13 controls the purge valve 7 and the vent valve 8 to reduce the pressure in the fuel tank 1 to a predetermined negative pressure P1, The state of pressure rise (DELTA P) in the fuel tank 1 in the closed closed state is monitored to determine the failure. The failure diagnosis device controls the purge valve 7 and the vent valve 8 to reduce the pressure in the fuel tank 1 to a predetermined negative pressure P1 and then to increase the pressure rise state? P (The pressure increase amount from the predetermined negative pressure P1), and also compares the pressure detection value Pn in the fuel tank 1 with the reference value M that increases at a predetermined increase rate, And a failure diagnosis device 13 for suspending or restarting the update of the value and performing a failure diagnosis.

However, the evaporative fuel processing apparatus according to the above-described prior art is configured to diagnose a failure without considering an external temperature change, which is an inexact result, that is, a possibility of false diagnosis.

It is an object of the present invention to provide a means for performing leakage diagnosis of the evaporative fuel processing apparatus and failure diagnosis of the purge valve by using a negative pressure naturally generated in the fuel tank according to the change of the outside air temperature.

This object is achieved according to the present invention by a method comprising the steps of: a) confirming that the condition that the engine is stopped and the natural negative pressure in the fuel tank is generated is satisfied; b) measuring the operating time of the natural negative pressure switch during engine shutdown and storing the outdoor air temperature if the condition under which the natural negative pressure is to be generated is satisfied; c) when the engine is started, checking the operation time of the natural negative pressure switch, confirming whether the natural negative pressure switch is ON or OFF, checking the outside air temperature, and calculating a variation amount of the outside air temperature during the engine stopped time; d) determining whether the operating time of the natural negative pressure switch has elapsed after the predetermined time has elapsed during engine stoppage; e) if the operation time of the natural negative pressure switch has passed a predetermined time, confirming whether the natural negative pressure switch is on or off; f) determining whether the purge valve has started its maximum opening control if on or off of the natural negative pressure switch is confirmed; g) setting and calculating a limit elapsed time according to the fuel level after the maximum opening control of the purge valve is started when the maximum opening control of the purge valve is started; i) determining whether a limit elapsed time corresponding to the fuel level has passed; And h) diagnosing a clogging fixation error of the purge valve when the time limit has passed over the fuel level, diagnosing the failure of the evaporative fuel processing apparatus using the natural negative pressure.

The step d) further includes the step of diagnosing a small leakage error, a purge valve open fixing error diagnosis, or no leakage when the operation time of the natural negative pressure switch has not elapsed during a period of d-1) stopping the engine .

Wherein the step (f) comprises the steps of: (f-1) partially opening the purge valve to diagnose a large leakage error if the maximum opening control of the purge valve is not started; And f-2) determining whether the natural negative pressure switch has been operated when the purge valve is partially open, proceeding to step e) if not, and proceeding to step d-1) can do.

The step i) includes: i-1) determining whether the natural negative pressure switch has been operated if the limit elapsed time according to the fuel level has not passed, and if not, proceeding to step i); i-2) if the natural negative pressure switch has been operated, it is determined whether the possibility of occurrence of a leakage error during engine stop should be considered; i-3) diagnosing that there is no leakage of the fuel tank system and diagnosing that there is no fixing of the purge valve when the possibility of leakage error during engine stop is not taken into consideration; And (i-4) diagnosis of a large leakage error and diagnosing that there is no fixing of the purge valve when considering the possibility of leakage error during engine stop.

According to the present invention, the leakage diagnosis of the evaporative fuel processing device and the failure diagnosis of the purge valve can be performed by using the negative pressure naturally generated in the fuel tank according to the change of the outside air temperature, And the reliability of the fault diagnosis of the purge valve can be improved.

1 is a graph for explaining the operation of an evaporative fuel treatment apparatus according to the prior art.
2 is a graph for explaining the operation of the evaporative fuel treatment apparatus according to the prior art.
3 is a flow chart for explaining a method for diagnosing a failure of an evaporative fuel processing apparatus using a natural negative pressure.
4 is a block diagram for explaining a method for diagnosing a failure of an evaporative fuel processing apparatus using a natural negative pressure.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, the well-known functions or constructions are not described in order to simplify the gist of the present invention.

FIG. 3 is a flowchart for explaining a method for diagnosing a failure of an evaporative fuel processing apparatus using a natural negative pressure, and FIG. 4 is a block diagram for explaining a method for diagnosing a failure of an evaporative fuel processing apparatus using a natural negative pressure.

In order to facilitate understanding of the evaporative fuel treatment apparatus, FIG. 1 can be referred to.

Hereinafter, a process for fault diagnosis of the evaporative fuel processing apparatus using the fault diagnosis method of the evaporative fuel processing apparatus using the natural negative pressure according to the present invention will be described with reference to FIG. 3 and FIG.

First, the natural negative pressure switch 50 may be installed in a vapor passage or a fuel tank. The natural negative pressure switch 50 is made of a switch that is brought into contact when the pressure inside the fuel tank or the pressure of the vapor passage falls below a preset pressure due to the fall of the outside air.

In order to diagnose the failure of the evaporative fuel processing device using the natural negative pressure switch 50, it is checked if the engine is stopped and the conditions under which natural negative pressure in the fuel tank is generated are satisfied (S1, S2)

That is, when the engine is stopped, stopped, and parked, a condition that a natural negative pressure is generated when the outside temperature is approximately 6-8 DEG C is satisfied. Therefore, the engine control unit ECU receives information on the communication from each device and the sensor, the natural negative pressure switch 50, the outside air temperature, the engine stop timer 40, and the like, And whether the fuel level is maintained at an appropriate level (approximately 80%).

Subsequently, when the conditions under which the natural negative pressure is to be generated and the above conditions are satisfied, the operation time of the natural negative pressure switch 50 is measured during the engine stop, and the external air temperature is stored (S3)

When the engine is started in this state (S4), the operation time of the natural negative pressure switch 50 is checked, and it is confirmed whether the engine is on or off, and the external air temperature is checked. (S5)

Then, it is determined whether the operation time of the natural negative pressure switch 50 has elapsed for a predetermined time, for example, 5 minutes during stopping the engine. (S6)

At this time, if the operation time of the natural negative pressure switch 50 does not exceed the preset time during engine stoppage, it is diagnosed as a small leakage error, a purge valve open fixing error diagnosis, or no leakage.

However, if the operation time of the natural negative pressure switch 50 has passed the predetermined time, it is confirmed whether the natural negative pressure switch 50 is on or off. (S7)

When the natural negative pressure switch 50 is turned on or off, it is determined whether the maximum opening control of the purge valve 7 has started. (S8)

When the maximum opening control of the purge valve 7 is started, a limit elapsed time corresponding to the fuel level after the maximum opening control of the purge valve 7 is set and calculated (S9)

Then, it is judged whether the time limit of the fuel level has passed. (S10)

If the limit elapsed time corresponding to the fuel level has passed, it is diagnosed that the purge valve 7 is closed and fixed. (S11)

On the other hand, if the maximum opening control of the purge valve 7 has not been started, a part (7-10%) of the purge valve 7 is opened to diagnose a large leakage error (S12)

When the purge valve 7 is partially opened, it is determined whether the natural negative pressure switch 50 has been operated. If the purge valve 7 has not been operated, the operation time of the natural negative pressure switch 50 during the above- (S6). If the operation has been performed, the flow advances to step S14 for diagnosing the above-mentioned small leakage error, purge valve open fixing error diagnosis, or no leakage.

On the other hand, if the limit elapsed time according to the fuel level has not passed, it is determined whether the natural negative pressure switch has been operated. If not, the limit elapsed time according to the fuel level after the maximum opening control of the purge valve 7 is set and calculated The process proceeds to step S9. (S15)

Then, if the natural negative pressure switch 50 has been operated, it is determined whether or not the possibility of occurrence of a leakage error during engine stoppage should be considered (S16)

When the possibility of occurrence of a leakage error during engine stop is not taken into consideration, it is diagnosed that there is no leakage of the fuel tank system, and diagnosis is made that there is no fixing of the purge valve (S18)

However, in consideration of the possibility of occurrence of a leakage error during engine stop, it is diagnosed that there is a large leakage error and it is diagnosed that there is no fixing of the purge valve. (S17)

Each of the above-described processes will be described in more detail.

If the purge valve 7 is closed and fixed in the natural negative pressure mode, when the vehicle is stopped and parked after the engine is stopped, the condition that the external temperature is lowered so that a natural negative pressure can be generated in the fuel tank is satisfied. Is closed, the natural negative pressure switch 50 operates as long as there is no other leakage error, so that the engine control unit 11 determines that there is no leakage error. Even when the engine operation is started and the purge valve 7 requests the open control for diagnosis, the actual purge valve 7 is closed and thus the natural negative pressure switch 50 is not operated, It is determined that there is a large leakage error. However, when the normal negative pressure switch 50 does not operate even after the normal purge control is started and the purge valve 70 is opened to the maximum and the specified time has elapsed, the engine controller 11 diagnoses the purge valve fixing error not the large leakage error do.

When the driver turns on the ignition key when the external temperature is sufficiently lowered (6-8 deg. C) and the natural negative pressure switch 50 can be operated, the engine control section 11 switches the natural negative pressure switch 50, Confirms the operation time of the natural negative pressure switch 50 communicating with the module or storing it, and confirms the position of the natural negative pressure switch 50 at present. Here, the position of the natural negative pressure switch 50 maintains the open position unless a negative pressure is formed in the fuel tank. Therefore, even when the engine is started, it is checked whether the natural negative pressure switch 50 is in the open position. If the natural negative pressure switch 50 is in the open (off or on) position, the purge valve 7 can start to diagnose the closure fixing error.

Even when the purge valve 7 is closed and closed, the natural negative pressure switch 50 is operated when the natural negative pressure condition due to the change in the external temperature is sufficiently satisfied. Because the purge valve 7 is closed, the purge passage of the evaporative fuel processor, the evaporation passage, and the like are closed to cause the natural negative pressure switch 50 to operate when the negative pressure is generated. However, If the natural negative pressure switch 50 does not operate even if the control is started and the phenomenon continues even after a predetermined time has elapsed, it can be determined that the purge valve 7 is a close fixing error. This is because even if large leakage exists, the natural negative pressure switch 50 can operate if the purge valve 7 is fully opened by the purge valve 7 control.

As described above, the energization control unit 11 controls the operation time of the natural negative pressure switch 50 when the engine is stopped, the initial position of the natural negative pressure switch 50 before starting the engine, The position of the natural negative pressure switch 50 is judged when the predetermined time has elapsed and the purge valve 7 is closed.

When the natural negative pressure switch 50 is appropriately operated by the natural negative pressure during engine stoppage and parking or stop of the vehicle and it is judged that there is no leakage error, it is determined that there is no leakage error during engine stoppage and engine start- If the large leakage error does not occur, the natural negative pressure switch 50 does not operate even if the purge valve 7 is opened for the leak diagnosis. However, in this case, there is a possibility of a large leakage error or a closure fixing error of the purge valve 7. In the case of a large leakage error, when the control of the purge valve 7 is started and the purge valve 7 is fully opened For example, 30-100%), the natural negative pressure switch 50 is closed. On the other hand, since the control of the purge valve 7 is started and the purge valve 7 is closed and fixed even when the maximum opening request is received, the natural negative pressure switch 50 is not operated. Therefore, the engine control unit 11 recognizes the difference and calculates the elapsed time during the control of the purge valve 7 with the maximum opening to check whether the natural negative pressure switch 50 is on or off, do.

On the other hand, another embodiment will be described.

Prior to the description, the operation of the natural negative pressure switch 50 by the natural negative pressure generating condition and the peripheral negative pressure during the stoppage of the engine is the same as that described above.

When the engine starts, check the operation time of the natural load switch during stop of the engine (or check the amount of change in pressure generated by the natural load). If the natural negative pressure switch 50 has been operated, at least the opening of the purge valve 7 It can be determined that the fixing error has not occurred. This is because the purge valve 7 is located in the purge passage connecting the fuel tank system, the evaporative fuel treatment device and the intake manifold of the engine.

However, if the natural negative pressure switch 50 does not operate during engine stoppage, this means that the engine stoppage time was too short or there was no change in the outside air temperature enough to generate a natural negative pressure, or there was a large leakage in the evaporative fuel processor It can be judged that the canister funnel valve 7 has been opened and fixed. The engine control unit 11 judges such a condition and performs opening of the purge valve 7 for large-scale leak diagnosis before the opening control of the purge valve 7 starts. (The opening degree is approximately 7-10 %) If the purge valve 7 is opened and the natural negative pressure switch 50 is operated, it is judged that there is no leakage error or the condition under which the natural negative pressure is formed is not satisfied, and it is diagnosed that there is no error. Alternatively, a small leakage error may be advanced by referring to the natural negative pressure generating temperature condition.

However, when the purge valve 7 is open (approximately 7-10%) for large-scale leak diagnosis, even though the natural negative pressure switch 50 has operated properly during engine stop and vehicle parking or stopping (approximately 5 minutes) If the natural negative pressure switch 50 does not operate, the engine control unit 11 determines that there is an error, and waits until control of the normal canister purge valve 7 is started. When the control of the canister purge valve 7 is started, the maximum opening control step is performed after the opening start control, and the purge valve 7 is opened by about 30-100% in the maximum opening control step. And receives the information from the fuel level sensor 20 from the start of the opening control, and sets a time limit until the natural negative pressure switch 50 is activated according to the fuel level.

(Or the pressure value sensed by the fuel tank pressure sensor 10) before the time limit, if the engine control section 11 considers that a leakage error such as the opening of the fuel tank cap may occur during the engine stop, When activated, it can be diagnosed that a large leakage error exists. This is because, even if there is a large leakage error, the natural negative pressure switch 50 can operate when the purge valve 7 is opened to the maximum. However, if the natural negative pressure switch 50 does not operate even after the time limit has elapsed since the maximum opening control of the purge valve 7 is started, it can be determined that there is a closure fixing error of the purge valve 7.

However, if the engine control unit 11 does not take into account the possibility of a leakage error such as the opening of the fuel tank cap during engine stop, the natural negative pressure switch 50 (or the fuel tank pressure sensor 10 Pressure value) is operated, it can be determined that there is no closure fixing error in the purge valve 7 in the fuel tank system, that is, the evaporative fuel processing apparatus. However, if the natural negative pressure switch 50 (or the fuel tank pressure sensor 10) does not operate even after the time limit has passed, the canister purge valve 7 is determined to have a closure fixing error and the error is diagnosed.

On the other hand, in order to set the time limit for the fuel level, the fuel level value sensed from the fuel tank fuel level sensor 20 may be considered, and the amount of gas trapped in the canister may be considered. When the trapped gas amount is large, the time limit is set to be high, and when the trapped gas amount is small, the time limit can be set to be small. Alternatively, the time limit may be set in consideration of the fuel temperature value read in the fuel tank or the modeled fuel temperature, or the time limit may be set according to the outside temperature. This is because a relatively high time is required when the ambient temperature is high.

As described above, it is possible to diagnose the leakage of the evaporative fuel processing device by using the negative pressure naturally occurring in the fuel tank according to the change of the outside air temperature, and to diagnose the result diagnosed based on the natural negative pressure, By confirming the final error determination, the reliability of the leakage diagnosis of the evaporation fuel processing apparatus and the diagnosis of the failure of the purge valve can be enhanced.

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 embodiments, but, on the contrary, It is obvious to those who have. Accordingly, it should be understood that such modifications or alterations should not be understood individually from the technical spirit and viewpoint of the present invention, and that modified embodiments fall within the scope of the claims of the present invention.

3: Canister 7: Purge valve
10: pressure sensor 11: engine control unit
20: fuel level sensor 40: timer
50: Natural negative pressure switch

Claims (4)

a) confirming that the condition that the engine is stopped and the natural negative pressure in the fuel tank is generated is satisfied;
b) measuring the operating time of the natural negative pressure switch during engine shutdown and storing the outdoor air temperature if the condition under which the natural negative pressure is to be generated is satisfied;
c) when the engine is started, checking the operation time of the natural negative pressure switch, confirming whether the natural negative pressure switch is ON or OFF, checking the outside air temperature, and calculating a variation amount of the outside air temperature during the engine stopped time;
d) determining whether the operating time of the natural negative pressure switch has elapsed after the predetermined time has elapsed during engine stoppage;
e) if the operation time of the natural negative pressure switch has passed a predetermined time, confirming whether the natural negative pressure switch is on or off;
f) determining whether the purge valve has started its maximum opening control if on or off of the natural negative pressure switch is confirmed;
g) setting and calculating a limit elapsed time according to the fuel level after the maximum opening control of the purge valve is started when the maximum opening control of the purge valve is started;
i) determining whether a limit elapsed time corresponding to the fuel level has passed; And
and h) diagnosing the closure fixation error of the purge valve if the time limit of the fuel level has passed.
Fault Diagnosis Method of Evaporative Fuel Treatment System Using Natural Negative Pressure. The method of claim 1, wherein
The step d)
d-1) diagnosing a small leakage error, purge valve open fixing error diagnosis, or no leakage when the operating time of the natural negative pressure switch has not elapsed during the engine stoppage,
Fault Diagnosis Method of Evaporative Fuel Treatment System Using Natural Negative Pressure. 3. The method of claim 2,
The step (f)
f-1) opening the purge valve partially to diagnose a large leakage error if the maximum opening control of the purge valve has not been started; And
f-2) judging whether the natural negative pressure switch has been operated in a state in which the purge valve is partially opened, proceeding to step e), if not, proceeding to step d-1) ≪ / RTI >
Fault Diagnosis Method of Evaporative Fuel Treatment System Using Natural Negative Pressure. The method according to claim 1,
The step i)
i-1) judging whether the natural negative pressure switch has been operated if the limit elapsed time according to the fuel level has not passed, and if not, proceeding to step i);
i-2) if the natural negative pressure switch has been operated, it is determined whether the possibility of occurrence of a leakage error during engine stop should be considered;
i-3) diagnosing that there is no leakage of the fuel tank system and diagnosing that there is no fixing of the purge valve when the possibility of leakage error during engine stop is not taken into consideration; And
i-4) diagnosing a large leakage error when considering the possibility of a leakage error during engine stop, and diagnosing that there is no fixing of the purge valve.
Fault Diagnosis Method of Evaporative Fuel Treatment System Using Natural Negative Pressure.


KR1020120117757A 2012-10-23 2012-10-23 Method for diagnosing stuck of evaporated fuelprocessing system using nature negative pressure KR101955634B1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07189831A (en) * 1993-12-27 1995-07-28 Nissan Motor Co Ltd Diagnosing device for fuel evaporative gas suppressing device
JPH08270480A (en) * 1995-03-29 1996-10-15 Toyota Motor Corp Failure diagnostic device for evaporation purge system
KR20020061029A (en) * 2001-01-12 2002-07-22 씨멘스 오토모티브 주식회사 Evaperative system leak check by underpressure after engine stop
KR20050068022A (en) * 2003-12-29 2005-07-05 씨멘스 오토모티브 주식회사 Method for detecting leak of fuel system
KR100756861B1 (en) * 2006-10-31 2007-09-07 지멘스 오토모티브 주식회사 Method for diagonsing full open stuck of canister purge valve
KR100858620B1 (en) * 2007-04-09 2008-09-17 콘티넨탈 오토모티브 시스템 주식회사 Method for diagnosing leakage on evaporative gas system
KR20100004773A (en) * 2008-07-04 2010-01-13 콘티넨탈 오토모티브 시스템 주식회사 Method for diagnosing stuck of canister purge solenoid valve of car

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07189831A (en) * 1993-12-27 1995-07-28 Nissan Motor Co Ltd Diagnosing device for fuel evaporative gas suppressing device
JPH08270480A (en) * 1995-03-29 1996-10-15 Toyota Motor Corp Failure diagnostic device for evaporation purge system
KR20020061029A (en) * 2001-01-12 2002-07-22 씨멘스 오토모티브 주식회사 Evaperative system leak check by underpressure after engine stop
KR20050068022A (en) * 2003-12-29 2005-07-05 씨멘스 오토모티브 주식회사 Method for detecting leak of fuel system
KR100756861B1 (en) * 2006-10-31 2007-09-07 지멘스 오토모티브 주식회사 Method for diagonsing full open stuck of canister purge valve
KR100858620B1 (en) * 2007-04-09 2008-09-17 콘티넨탈 오토모티브 시스템 주식회사 Method for diagnosing leakage on evaporative gas system
KR20100004773A (en) * 2008-07-04 2010-01-13 콘티넨탈 오토모티브 시스템 주식회사 Method for diagnosing stuck of canister purge solenoid valve of car

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