Title of Invention

A SYSTEM AND A METHOD FOR DETECTING FAILURES IN A FUEL SYSTEM OF A VEHICLE

Abstract

A diagnostic system and method for detecting failures in a fuel system of a vehicle includes a fuel level monitoring module that determines a first change in a first fuel level of a first fuel tank based on data received from a first fuel level sensor and determines a second change in a second fuel level of a second fuel tank based on data received From a second fuel level sensor. A sensor diagnosing module evaluates operation of the second fuel level sensor based on the first change in the first fuel level.

Full Text

QM Botounco Ha. GP-MS3S5-PTE-C0 ABOmsy Pocket No. 854DP-0W509 SYSTEM FOR DETECTING FAILURES IN FUEL SYSTEMS FIELD DF THE INVENTION [000*1] The present disclosure relates to fuel level monitoring in a vehicle, and more particularly to monitoring a fuel level in a vehicle having primary and a secondary fu&i tanks. BACKGROUND Or THE INVENTION (0002] The statements in this section merely provide background information related to She present dls&osure and may not constitute one- art [QQ03J Internal combustions engines combust ars air and fuel (A/F) mixture within cylinders to produce drive torque, Mare specifically, the combustion events reciprocally drive ptet&ns that drwe a crankshaft to provide torques output from the engine. The fuel is delivered to the engine by a fuel system. The fuel systems of sorae vehicles include a plurality of fuel tanks. For example, some fuel systems include 3 primary fuel tank and a secondary fuai tank, that share a common filling neck, [0004] The fuel levels within the fuel tanks are monitored and the vehicle operator is informed as to the amount of fuel remaining m each tank. More specifically, a fuel level sensor is provided in each tank. Each fuel level sensor is re&poresiva to the fuel level in a respective lank and generates a signal based the fuel level. The amount of remaining fuel Is determined based on the signals. Conventional fuel level monitoring systems include rationality diagnostics to determine whether the fuel level sensors are functioning property. 1 Attorney Owkel No, 354OP-00&5DB SUMMARY [0005] A diagnostic system and method for detecting failures in 3 fual system of a vehicle includes a fuel level monitoring module shat determines a first change in a first fuel level of a first fuel tank basad on data received from a first fuel level sensor and determines a second change in a second fuel I eve! of a second tuts* tenfc based on data received from a second fuel level sensor, A sensor diagnosing module evaluates operasion of the second fuel tewjl sensor based on the first change in tie first fuel level [0006] In other features, the sensor rjiarjnas!n,g modules deterraioss a fault state of the second fuel ievai: sensor 'when the first change exceeds a variation threshold and the second fuel level is one of less than and equal to an empty threshold- The fuel tovsi monitoring module change in too secorsd fii&l leva! when at least one of the first change fails; to exceed a variation threshold and the second fuel level exceeds an enpty threshold. fOQOTJ In other features, tie sensor diagnosing module signals one of a pa$s state and a failure state of the second fuel level sensor based on the second change and a cfiange threshold. The sensor diagnosing module signals the pass state when the second change ©xweds She change threshold and signals the failure slate wnen the second change is one of less than or equal to tha change tsiresbosd. The system further oomprisas th« first and second fuel level sensors. The fuel system includes a fueling rseck common to trie first fuel 2 GM Ratarenoe No. 6P-30S3t5-PTE.CP Attorney Dcckat No. 8540P-X50509 lank and the secor. turn tevsi monitoring module determining the first change in the firs", fuel level of she first fuel tank. [0008] In Other features, the system further comprises a control module that activates an electric transfer pump when tfie first fuel level of the first fuel tank falls Iwskwv a control threshold, wherein the electric transfer pump transfers fuel from file second fuel tank to the first fuel tank, The control module. deactivates the etectric transfer purap when or» of the first fuel tank reaches a Hull state and tr» second fuel tank fails to an empty slate. The diagnostic system is activated wlisn an ertgsne of the vehicle is turned en. (000&3 FurlJier areas of applicability will become apparent from the description provided herein. It should be understood thai the descriptor! and specific examples are intended for purposes of iHpsfrafion only and are not intended to limit the scops of the present disclosure. DRAWINGS J0010| The drawings described herein are for ffluslrsfion purposes only arid are not Intended to limit tha scope of the present disclosure in any way. [0011] FIG. 1 is a functional block diagram illustrating an exemplary vehicle including a diagnosis system according to tha- present invention!: [0012] FIG. 2 is a functional Dfoek dta-gram iNustralmg primary and secondary fuel tanks Recording to Bis present Invention; 3 OM ReteatiM No. QP-309395-PTE GO Attorney Docket !■», 854OP-QO05Q9 (0043) FIG. 3 is a functional block diagram illustrating m exemplary module that executes the diagnostic system of the present invention, and [0914] FIG. 4 is a flowchart illustrating exemplary steps executed trie fjiagftostic system of tie present invention. DETAILED DESCRIPTION (0015] The following description of the preferred embodiment is r-wrely exemplary in nature antj is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the sam« reference numbers wiil be used in the drawings to identify sirriila? elements. As used herein, the term rnodute refers to an application specific integrated eireurf (ASIC}, an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one « more software or firmware programs, a combinational togic Circuit, or other suitable component* that provide the described funclkmality. [001SJ A fuel tevel sensor may improperly report fiat a corresponding fuel tank is at an empty state (i.e. stjck-ln-empty failure). If a siuck-in-eropty failure occurs, a transfer pump that transfers fuel from tre secondary fuel tank to the primary fuel tank may net operate, Therefore, the fuel in the secondary fuel tank will not be accessible to the engine, [0017| A stuck-in-smpty failure of in© secondary fuel sensor may falsely ersaote and/or disable diagnostics such as an evaporative emission control (EVAP) monitor based on incorrect sensing of the fuel level in the secondary fuel Sank, QM Reference Nc SP-3fJS39S-PTE-C0 ASlcrney i&ocfcet No l5*flP-00DSOB (00181 Referring now to Figure 1, an eaempiary vehicle system 10 include* an engine 12 having an intake manifold 14 and an exiiausf manifold 16. Air is drawn into the intake manifold 14 through a tiirotde 18 The air is mixed with fuel, and the fuel and air mixture Is compressed and ignited within a cylinder 2Q to reciprocally drive a piston (r»t shown) within Sie cylinder 20. Although a single cylinder 20 is shown, it is anticipated that the engmfl 12 can include a plurality of cylinders 20. The piston rotataMy drives a crankshaft (not shown) :o provide a drive torque output. Fuel « delivered to the engine 12 by a fuel system 22, which includes e fueling regulator 24, a primary fuel tank 26, end a secondary fuel tank 28. In She present Mnplemertsfcn, tfie primary and secondary fuel tanks 28, 28 share a single fueling neck 30 During a refueling event, fuel is fed to the primary am secondary fuel tanks 26, 26 simultaneously via the fueling neck 30. [0019] Primary and secondary fuel level sensors 34, 38 sens© primary and secondary fuel levels within tha primary and secondary fuel tanks 26, 28, respecSveiy, and generate primary and secondary fuel signals indicating the respective fuel levels In various embodiments, the primary and secondary fuel level sensor* 34, 36 may include a component such as a "float* that is buoyant and floats at a surface of trie fuel of each of the respective fu&l tanfcs 26, 28 The primary and secondary fuel level sensors 34, 36 may generate primary and secondary fusl signals based on the position of the floats within the primary and secondary turn tanks 26. 28, respaclivdy. A fuel transfer mechanism such as an 5 CM Reference tic. GP-&S93S&-FTE-CD Attorney Docket No, BW0P-003S0& electric transfer pump 38 transfers fuel between ths primary and s&condary fuel tanks 26, 28. |0028] A control module 40 includes a processor, memory sue* as random access memory (RAM), read-only memory (ROM), anrttar other suitable electronic storage*. The control module 40 communicates with the fueling regulator 2-1, tine primary fuel level sensor 34, and the secondary fuel level sensor 35, Addition al ly. the control module 40 fray receive input from ettier sensors 42 of the exemplary vehicle *0 including, but not limited to, oxygen sensors, engine cocsarH temperature sensors, mass airflow sensors, and'or engine speed sensors, [0021] The "ccitsros module 40 executes a sensor diagnostic system of the present invention The sensor diagnostic system detects awl reports a 'sUjck-in-nafjge" {e.g. stuck-irv&mply) failure slate of the secondary fuel »vel sensor 36 based on the primary and secondary fuel signals. In other wards, the sensor diagnostic system determines whether the secondary f«el fevsi sensor 36 is improperly sensing that tie secondary fuel tank 2S is at an empty state. Although tlio present irnplenierrtafet describes a sensor diagnosis;; system operating an the secondary fuel level sensor 36, those sMIIed in ths art can appreciate that a sensor diagnostic system of the primary fuel level sense* 34 may function similarly to the sensor diagnostic system described herein {00.22] Referring to FIG. 2, the primary and the secondary fuel tanks 28, 28 are shown. The primary fuel tank 26 supplies fuel to the engine 12 during operation erf the vehicle 10, Preferably, the ©ontol module 40 activates the 8 CM R(?ter Attorns? Docks' Ho SMQP-0iXK05> electric transfer pump 38 to supply fuel from the secondary fuel tank 28 to tne primary fuel tenK 26 v/hen the primary fuel level fails below g contKil threshold. The primary fuel tank 26 also includes a first Ml threshold thai indicates whether ttia primary fuei tank 26 has reached a full state. The secondary luel tank 26 includes a sacorid full threshold and an empty thresh:*! indicaiive of a full state and empty state, respectively, 40 deactivates the electric transfer pump 38 when either the primary fuel tank 20 fetiches the full state or the secondary fuel tank 28 falls to the empty stale. [0023J Referring now to FIG. 3, the control module 40 is shown in more detail. The control module 46 includes an exemplary sensor diagnostic system 100 o? the present invenltari. The sensor diagnostic system 100 includes a fuel level monitoring module 102 and a sensor diagnosing module 104, The sensor diagnostic system 100 stores a value of the primary fuei level (i.e. the previous primary fuei level) in memory during a previous key eyeie of the vehicle ID. In ins present implementation, the senses diagnostic system 100 stows the previous primary fuel level when the engine 12 id turned off. [0024] The fuei: ievei monitoring module 102 communicates with the sensor diagnosing module 104 and detects changes in the primary fuel level of the primary fuel tank 36 based on input received from primary fuel level sensor 34. The fuei level monitoring module 102 retrieves the previous primary fuel fevei from memory and determines a current primary fuel level upon activation of the engine 12. Hie fuul teyal monitoring module 102 then calculates a change batwssn the previous and current primary fuel levels and determine E. whether tne 7 6*1 Reference No. AKsmoy Docket Ma 8540P 00050B change exceeds a variation threshold. If the fuel level monitoring module 10? determines that current primary Su&i level has increased relative to the previous primary fuel level, the sensor diagnostic system 100 assumes that a refueling event gf the fueling system 22 has occurred [0025] As noted previously wish reference to FIG. 2, fuel ss fed to the primary and secondary fu&l tanks 26, 28 sirnuNarsaausly via the fuoiing neck 30 during a refueling event Therefore, the fuel level monitoring module 102 further assumes that the secondary fuel tank 28 received fuel during the refusing event based on tie increase of tbe current primary fuel level, [0026] The fuel level mentoring module 102 then determines whether the secondary fuel level of the secondary fuel tank 28 exceeds the empty threshold based on input received from the secondary fuel sensor 36, The sensor diagnosing modal© ItM signals a failure state or a pass state of the secondary fuel level sensor 36 based on *ha determinations of the fuel level monitoring module 102. Specifically, the diagnosing module 104 signals a failure state if the fuel level monitoring module 102 determines that tie secondary fuel level did riot exceed the empty threshold. |09271 However, if the fuel level monitoring module 102 fa*s to detect an increase in current primary fuel level (i.e. no refueling event occurred prior to the current key eyd*), the fuel lave? monitoring module 102 dstermirms a change in secondary fuel seval arfter the vehicle 10 travels a caiibrated distance Tne sensor diagnosing module 104 signals one of a failure state or a pass state based on the change in the secondary fuel level. If the change in the secondary 8 6M R«*i»si'i« tie. GP-3083»S-HTE-C» Mtomev Poeka » B54OP-0OM0S fuel: level exceeds a change threshold, the sensor diagnosing module 104 signals the pass state. However, f the change in the secondary fuel level falls b&law (he change threshold, this sensor diagnosing module 104 signals a failure stale indicating a stuc* failure state of the secondary foes level sensor 36. [0028] Referring now to FIG. 4 an exemplary method 400 tor controlling the diagnostic system will be- described in mote detail. Control begins the method 400 at step 402, In Step 404, control determines whether the engine 12 is on. If control determines ttiat tr» engine 12 «s off, control returns to step 404. If control determines that the engine 12 is on, control proceeds to step 406 Preferably, $ usetfop&rator of th§ vehicle 10 fuels ihe fuel system 22 prior to sumsng on the engine 12. [0029] In step 406, control retrieves a previous primary fut*l levol In step 408, control datoranines the current primary fuel level In step 410, control determines a change between the current primary fuel leva! and the pravous primary fuel level retrieved from memory. Irs step 412, determines whether the change exceeds a variation threshold. If control determines that the change doss not sxceed the varfartion threshold, control proceeds to step 416. If control determines that the change does exceed the variation threshold, control proceeds to step 414. In step 414, control detamines whether the secondary fuel level exceeds the empty threshold. If control determines that the secondary fuel level does not exceed She empty threshold, control proceeds *o step 420. Hov/ever, if control determines that secondary fu« level does exceed the empty threshold, control proceeds lo step 418, a GM Reference No. GP 309395-PTE.CO Attorney OocKet Ho. 8540?-000505 [0030] ln: 6t*p 416- control determines a change in the secondary fuel level after the vehicle 10 travel! a calibrated distance Irs siep 418, control determines if the change in ihe secondary fuel level exceeds a Changs threshold. If control determines that the change in the secondary fuel level does exceed the change threshold control proceeds to step 420 It control determines that the change its the secondary ftiel level rioe* not exceed ttre change threshold, control proceeds to step 42.2. In step 42D, oentrol signals a pass state indicating that the secondary iuel tevei sensor 36 is operating properly, in step 422, control signals a failure state indicating that the secondary fuel level sensor 38 is Improperly reporting a sfcudk-in-empty state The method 400 ends in step 424. [0031] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forma Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so Im'sted since oiher modifications will become apparent to the skied practitioner upon a study of the drawings, the specification and the follows r*g claims 10 6M Reference to. SP-S0333S-PTF-OP Ationwy Pocks! Ma. a54OP-0DDSQ9 » CLAIMS What is claimed is; 1. A diagnostic system for defecting failures in a fuel system of a v&tiscle, comprising: a fuel level monitoring module thai: determines a first change in a first fuel level of a first fuel tank bas&d on data received from a first fuel level sensor; and d-etemiines a second change in a second fuel level a! a second fuel tank based on data received' from a second fuel level sensor; arid a sensor diagnosing macule that evaluates operation of said seorwvd fuss level sensor Dasetf on said first change in said fsrai fuel level. 2, The system of claim 1 wherein said sensor diagnosing module determines a fa*si* state of said second fuel level sensor when sasd first chsnge exceeds a variation threshold and said second fuel level is one of less than and equal to an empty threshold, 3 The "system of claim * wherein said fuel level monitoring module determines said second change in said second fuel level when al least one of said first change fails to exceed a variation threshold ana said second fuel level exceeds art empty threshold. 11 AMnt!»y Deckel No. 854W-CO05O9 4. The system of claim 3 wherein said sensor diagnosing module signals one of a pass state ami a failure stale of said second sua level mmoi based on sale ssoond change and a change threshold. 5. The system of claim 4 wharein said sensor diagnosing module signals said pass state when said second change exceeds said change thfeshoW and signals said faium sate when said second change is one of iess tnan or equal to said change threshold. 6. The system of claim I lurcher comprising sa*d iifst and second fuel level sensors. 7. The system oS claim 6 wherein said fuel system includes a fueling neck common to said first fuel tank and said second fuel teak, whemm said fueling neck receives fuel prbr to said fuel level monitoring module determining said first change in said first fuel level of said first fuel tank, 6. The system of claim 1 further comprising e control module feat activates BR electric transfer pgmp when sasd first fuai level of sak) First fuel lank falls below a control threshold, wherein said olctiric transfer pump transfers lues from said second fuel tank to said first fuel tank. 12 GM fiefwwice No, GP-309J9S-PTE-CD MMrmy Ccc*Bi No. 3S4OP- 9. The system of claim 6 wherein said control module deactivates ssid electric transfer pump whan one of said first fuel tank reaches a full state and said second fuel tank falls to an empty slate. 10. The system of claim 1 wherein sad diagnostic system is activated wh«« ars engine of said vehicle is turned oa 11. A diagnostic method fa? detecting failures HI a fuel system of a vehicle, comprising: determining a first changes in a first fuel level of a first fuel Tan* aased on data received from a first fuel fav#t sensor; determining a second change m a second fuel level of" a second fuel lank based on data received from a second fuel tevef sBn∨ and evaluating DfxraiJon of said second fuel level sensor based on said first change in said first fuel level. 12. The method of claim t \ further comprising determining a fault state- □f said second fuel level s«nsor when, said first change exceeds a variation threshold and sad second fuel level is one Q( less than arid equal to an empty threshold. 13 GM ftoteenos No. GP-SOSiJi-PTE-CD AMwrxiy Deckel No. a5«iP-»3U05fi'J 13. The method change in said second fuel level when at feast one of said first change fails to exceed a variation threshold and salts sseorid fuel level exceeds an empty threshold. 14. The metiod of claim 13 further comprising signaling one of a pasn state and a failure slate of said second fyel level sensor basse on said second change and a change threshold. 15. The method of claim 14 furtner comprising signaling said pass state when said second change exceeds said change threshold and signaling sa4 failure state whan said second change Is on* of less than or equal la said change thmslwid. 16. The method of claim 11 further comprising sensing ssid first fuel lei's! and said second fuel level. 17. The method of claim 16 further comprising including a fueling neck common So safe) first fuel tank and said second fuel tank, wherein said fueling neck recwas Suei prior So determining said first change In said first fuel level cf said first fuel tank. 14 GM Rclc«3i« MB. GP-3iS39S-PTE-C0 Attorney Octroi N.si. 85i«lr-OD0M8 18 Tfie method of claim 11 further comprising activating an electric Sransfer pump when said lirai fuel level at said first fuel sank falls below a control threshold, wherein gaicl etedfic transfer pump transfers fuel from sad sscond fust tank to saW first fuei tesnk . 19. The method of claim 18 further comprising deactivating saic electric Transfer pump wheo one of said first fuel sank reaches a full state and sski second fuel lank falls to an empty state. 15 20, Tha method of claim 19 further comprising activating said method when an engine of said vehicle is turned an. A diagnostic system and method for detecting failures in a fuel system of a vehicle includes a fuel level monitoring module that determines a first change in a first fuel level of a first fuel tank based on data received from a first fuel level sensor and determines a second change in a second fuel level of a second fuel tank based on data received From a second fuel level sensor. A sensor diagnosing module evaluates operation of the second fuel level sensor based on the first change in the first fuel level.

Documents:

00407-kol-2008-abstract.pdf

00407-kol-2008-claims.pdf

00407-kol-2008-correspondence others.pdf

00407-kol-2008-description complete.pdf

00407-kol-2008-drawings.pdf

00407-kol-2008-form 1.pdf

00407-kol-2008-form 2.pdf

00407-kol-2008-form 3.pdf

407-KOL-2008-(18-12-2013)-ABSTRACT.pdf

407-KOL-2008-(18-12-2013)-CLAIMS.pdf

407-KOL-2008-(18-12-2013)-CORRESPONDENCE.pdf

407-KOL-2008-(18-12-2013)-DESCRIPTION (COMPLETE).pdf

407-KOL-2008-(18-12-2013)-DRAWINGS.pdf

407-KOL-2008-(18-12-2013)-FORM-1.pdf

407-KOL-2008-(18-12-2013)-FORM-2.pdf

407-KOL-2008-(18-12-2013)-FORM-3.pdf

407-KOL-2008-(18-12-2013)-OTHERS.pdf

407-KOL-2008-(18-12-2013)-PA.pdf

407-KOL-2008-ASSIGNMENT.pdf

407-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

407-kol-2008-form 18.pdf

407-KOL-2008-PRIORITY DOCUMENT.pdf