Title of Invention	A DIAGONOSTIC SYSTEM AND METHOD FOR DETECTING FAILURES IN FUEL SYSTEM
Abstract	A diagnostic system and method includes a fuel level sensor that senses a fuel level in a fuel lank and a sensor diagnostic module that monitors a fuel transfer mechanism for a lime period, that calculates a change in the fuel level, and that evaluates operation of the first fuel level sensor baaed on the change and the predetermined period.

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iMKcte n-'Hi -> t i3«4 ! It / Irmr Du. SYSTEM FOR DETECTING FAILURES IN FUEL SYSTEMS FIELD OF THE INVENTION [0001 j The present disclosure relates to fuel level monitoring in a vehicle, and more particularly So montofing a fuel level in a vehicle having primary arid a secondary fuel tanks. BACKGROUND Of TH£ INVENTION [0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art, (0003] internal; oombusfens engines cornbtjst an asf and fuel INF) mixture within cylinders to produce drive torque. Mara specifically, the combustion events reciprocally drive pistons that drive a crankshaft to provide torque output from the engine. The fuel is detverea to the engine by a fuel system. The fuel systems of some vehicles include a plurality of fuel tanks. For example, some fuel systems include a primary fuel lank and a secondary fuel tank, wherein each fuel tank indyttes its own filer neck. [Q004] The fuel levels within She fuel tanks are monitored and line vehicle operator is Informed as to ihe amount of fuel remaining in each tank, More specifically, 9 fuel level sensor is provided in each tank. Each fuel level sensor is responsive 1o the fuel level in a respective tank and generates a signal based thereon, The amount of remaining fuel ss determined based on the signals. Conventional fuel level monitoring systems include ratanality diagnostics to determine whether the fuel level sensors are functioning properly, 1 ,*tlorr«y Dewol Wo. a$4i>pJli00K* SUMMARY [0005] A diagnostic system and method includes a fuel level sensor that senses a fuel level in a fuel tarsk and a sensor diagnostic module shai activates a fuel transfer mechanism for a isms period, that caleutates a change in the fits* level, and: that evaluates operation of the first lues lava! sensor based on the change and the predetermined period. [00Q81 irs other features, the system further comprises an enablement module that enables the system when the enablement module determine* an a&sence of active faults. The active faults include at least one of component diagnostic trouble cades, fuel level sensor out of range codes, and vehicle speed fault ©rjdes, {OCM37J In o'har features, the system further corapcises g fuel level detection module that detects input from the fuel level sensor and B second fuel level sensor wherein the second fuel sensor senses a fuel level of a second fuel tank. The fuel level detection module verifies thai She fuel level of the fuel tank exceeds wi empty threshold and the fuel level of tho second fuel tank is below 3 control threshold, The fuel level detection module determines a first fuel level of the fuel tank before activating the fuel transfer mschanssm and [email protected] a socond fuel level of the fuel lank after the time period. |000S] In other features, the sensor diagnostic modulo deactivates the fuel transfer mechanism when the time period exceeds a time threshold The sensor diagnostic module determines a fail state of the fuel level sensor wtien the change falls below a fuel change threshold arid determines a pass state of 2 CsM: Rol'or^ce No. GPP : E-CD the fuel level sensor when the charHja exceeds the fuel change threshold. The fail operation includes a stucMrvrange operation. [O0MJ Further areas of applicability v«il become appareni from the description provided herein, it should be understood that she description and specific examples are intended for purposes of illustration or% and are not intended to- limit the scope of the present disclosure. DRAWINGS (00101 ~he drawings described: herein are for illustration purposes or% and are not intended to limit she scope of the present disclosure in arsy way, [0011] FIG. 1 is a functional block diagram of ar> exemplary vehicle inciuding a diagnostic system according to ti» present invention; (0012] FIG. 2 is a functional block diagram illustrating primary and sacofKiat^ fuel tanks according to the present Invention; [0013] FIG. 3isa functional block diagram illustrating an exemplary module that executes the diagnostic system at the present Invention; arsd [0014] FIG. 4 is a flowchart illustrating the diagnostic system of the present irw&rrton. 3 QM Reference No GP-30S3SWTE-CD Attorney Docket No. g^QP-tJOuKa DETAILED DESCRIPTION [0015] The following description of the preferred embodiment is merely exemplary in nature and is irt no way intended to limit the invention, its application, or uses. For purposes ef clarity, the same reference numbers will be msec" in the drawings to identity similar elements. As used heroin, 'he term module refers ED an application specific integrated circuit (ASIC), an electronic circuit, u processor (snared, dedicated, or group} and memory that execute one or more software or firmware programs, a combinational logic circuit, or other suitable components that provide the described functionality [0016] A fusi level sensor may improperly report that a corresponding fuel tank is at a full state (i.e. stucMn-full failure). If a styek-in»fyll failure occurs, a transfer pump that transfers fuel from She secondary fuel tank to the primary fuel tank may unnecessarily remain active. Furthermore, a stuek4n-fu'l faikjre may lead to a inaccurate calculation of fuel volume thai falsuly enables and/or disables major diagnostics. [0017J Referring now to Figure 1, an exemplary vehicle system 10 includes an engine 12 having au intake manifold 14 and an exhaust manifold 16, Air is drawn into the infate manifold 14 through 8 throttle 18. The air is mixed with mat, and the fuel and air mixture is compressed and ignited within a cylinder 20 to reciprocally drive $ piston (not shown) w single cylinder 20 is shown, it is, anticipated that the engine 12 can include a plurality of cylinders 20. The piston rctatabSy drives a crankshaft (not shown) to provide a drive torque- output. Fuel is d&tiverw to the engine 12 by a fuel system 4 GM Rsler«ice No. «?-303SM-PTS-CD Atwnay Doc*el Mo, 34*0P-SO()S€'8 22, which includes a fueling regulator 24, a primary fuel tank 73, and a secondary tuel tank 28. In tiio present irnpiementatai. She primary ana secondary fuel lanks 26, 20 indycie respective fueling necks 30, 32. In various embodiments, Ihe primary and secondary fuel tanks 26, 28 may include a common fueling neck. [80183 Primary arai secondary fuel level sensors 34, 36 sansa fuel levels within first the primary arid secondary fuel tanks 26, 28. respectively, arid generate primary and secondary fuss signals indicating respective fuel levels In various, embodiments, the primary ancJ secondary fuel leva! sensors a*, 36 may include a component sucti as a "float" that is Duoyant awl floats at e surface of the fuel of each of the respective fuel tanks 26, 28. The primary and secondary fuel level servsers 34, 36 may generate primary and secondary fuel signals based on the position of the floats wiffw the primary and secondary fuel tanks 26, 28, respectively. A fuel transfer mechanism sueih as an electric transfer pump 38 transfers fuel between the primary arid secondary fuel tanks 26, 26. J0Q19] A cantac! modulo 40 commursica'.es with She fueling regulate' 24, the primary fuel level sensor 34, and She secondary fuel level sensor 36. Additionally, the control modus* 40 receives input from other sensors 42 of the exemplary vehicle ID including, out not limited to, oxygen sensors, engine coolant temperature sensors, mass airflow sensors, and/or engine speed sensors. The control module 40 executes a fuel sensor diagnostic system of the present invention. The fuel sensor diagnostic system evaluates the operatoisal state of the secondary fuel »v« sensor 36 based on the primary anti secondary fuel signals, For example, the fuel sensor diagnostic system determines whether 6 GM Raferrowe No. GP-3a93W-PTC.cn ABom«)i Docket No. 854DP-OXIS&8 ttie secondary fuel sensor 38 is in e •'gtuck-ifwange" {e.g. stuxk-in-full) failure; state or operating properly. In ottier words, this fijel sensor diagnostic system determines wlwirar the secondary fuel level sensor 36 is improperly, continuously sensing that the secondary fuel tank 28 is at a ful* slate, Although the present implementation illustrates a feel sensor diagnostic system operating on the secondary fuel level sensor 36, those skilled m ttie art can appreciate that a fuel sensor diagnostic system of the primary fuel level sensor 34 may function similarly to the fuel sensor diagnostic system described herein. [00201 Referring to RG 2, the primary and the secondary fuel tanks 26, 28 am shewn. The primary fuel ssrtk 26 supplies fuel to ttie engine 12 during operation of th« vehicle 10. Preferably, the electric transfer pump 38 supplies fuel from ttie secondary fuel tank 28 to ttie primary fuel tank 28 when the fuel level of the primary fuel tsnk. 26 falls below a control threshold. The primary fuel tank 26 also includes a first full threshold indicative of a full state of the primary fuel tank 26. The primary fuel level sensor 34 generates the primary fuel signal based on the actual fuel level of the primary fuel lank 26. (0021] The secondary fuel tank 28 inciudes a second: Mi threshold and m empty threshold, The second full threshold Indicates whether tie fuel level of the secondary fuel tank 2B has reached a full slate, and the empty threshold indicates whether the second fuel tank 28 has fallen to an empty slate. The secondary fuel sensor 38 generates the secondary fuel signal based on the actual fuel level of the secondary fuel tan*; 28, 6 GM Ftsfersnce Nsj. GP-SC93B4 PTE-CD Attorney Docks-, No BW0P-O3C5W [0022] Referring now to FIG. 3, the control module 40 is shown m more detail, The control module 40 includes an exemplary fuel sensor diagnostic system 1GO of she present invention. The fuel sensor diagnostic system 100 includes a fuel level detection module 102 era a sensor diagnostic module 104 [00233 An enablement module 106 communicates with trie other sefisors 42. The enaWwnerri module 106 determines whettar to snabla the fuel s&nsor diagnostic system 1®) by verifying that no active twite that may impact the proper operation of the futri sensor diagnostic system) 100 ewst The active faults include, but are not limited to, component diagnostic trouble codes, fuel leva! sensor out of range codes, snd vehicle speed fault codes, If no active faults exist that may prevent the proper operation of trio fuel sensor diagnostic system 100, tha enablement module 106 enables the fuel sensor diagnostic system 100. [0024] The fuel level detection module 102 communicates with the enablement moduts 106 and detects changes in fuel levels of the primary ana secondary fuel tanks 28, 28 based on input received from the primary and secondary fuel jevol soflso*s 34, 36, For example, the fuel level detection module 102 verifies whether the fuel level of the primary fuel tank 26 is below :hs control threshold and whether the fuel level of the secondary tank 28 exceeds the empty threshold. [0025J The sensor diagnostic module 104 communicates with the fuel level detecSiort module if>2. The sensor diagnostic module 104 activates the electric transfer pump 38 and stores a first time and a first fuel level value of the secondary fuel tank 28 when trio electric transfer pump 33 turns on. In the 7 GM Rsf€fen=e No. GP-XS394 PTE-CO Attorney ttosksi No 854QP-090506 present implementation, the electric transfer pump 36 transfers fuel from the secondary fuel tank 2-3 to the primary fuel tan* 26, The elecfeic transfer pump 3*5 transfer* fuel to the primary fuel tsn>; 26 gsntil m active time (i.e. a time period of active operation) of trie electee transfer pump 3S has axeMsded a time threshold. The sensor diagnostic modute 104 deactivates tie electric transfer pump 38 and determines # second fuel level value of the secondary fuel tank 28 when the active time of the transfer pump exceeds the lima threshold.. The sensor diagnostic module 104 then determines (whether a change in the fygl ieves (e.g. decrease in the fuel level) of Ihs secondary fuel tank 28, resulting from the operation of she eteclric transfer pump. 38, exceeds a fuel change threshold. [CMJ26J In the present Implementation, the time and fuel change thresholds are calibrated and oases on the operational characteristics of the eJecWc tfansfw pymp 38, If the change m fuel level of the secondary fuel tank 2B does not exceed the fuel change threshold, tits tensor diagnostic module 104 generates a failure control signal indicating a skiC*-in-full failure state of she secondary fuc- evol sensor 36, It the dharsge in fuel level of the secondary fuel tank 28 does exceed the fuel change threshold. the sensor diagnostic module 104 generates a pass control signal, [00271 Referring now to FIG. 4 an exemplsrv method 400 for contenfag the diagnostic system will be described in more detail Control begins the rrtrthod 400 at step 402. in step 404, control determines whether $ny applicable active faults have beer, detected, if any applicabte active faults exist, control returns to step 404, If control fails to detect any applicable active faults, 8 GM Rete-wira No, O3-3M304-PTE-C5 Atiomay Docket «o. 8640P-00&50B ssontrol proceeds to step 4Q6. In step 406, determines whether trie fual level of the primary fuel tank 26 is betow the control threshold, if the fuel level of the primary hte>, tank 26 is not below the control threshold, control proceeds to steo 422. It the fuel level of tries primary' fuel ten* 2fi is below the control threshold, control proceeds to step 40fi. In step 408, control determines whether the fusl level of she secondary fuel tarsk 2S Is below the empty threshold. If the fual level of the secondary fuel tank 28 is befe'w the empty threshold, control proceeds to step 422. If the fuel ievet qf the secondary fuel tanic 28 is not below the empty threshold, control proceeds to step 410. [0028] In slap 410 centre! activates the electric sransfer pump 33 In step 412, control determines whether an active sim© of the olactric transfer pump 38 exceeds the lime threshold. It ths active lime does not exceed the time Shra&heki, control returns to step 4t2. If tha active 'line dees ftxeesed the time threshold, control proceeds to step 414, Sn step 414, control deactivates trie electric transfer pump 3-8. In slep 418, control determines whether a change in the fuel level at the secondary fuel tank 28 exceeds a fuet change tnreshoJd. If the tnange m the fuel level does exceed the fuel ehangs threshold, control signals a pass state indicating thai the secondary fual level sensor 36 Is operating property in step 418. If the change in the fuel level doe* not exceed the fuel change threshold, control signals a failure state indicating thai ths secondary' fuel level senser 36 is In a stucMn-fuil state in step 420. The method 400 ends in step 422. S GM R«-teeric* Nti. OP-30939*-Pt£-CD AttoTwy Dceiel Ha. miOP-mOXe [0029] Thavj skilled >n the art can now appreciate from the foregoing description ttiai the broad teachings of the present invention can ba implemented in a variety of forms. Therefore, while this invention has Nwn described in cannectiors with partteutar examples thereof, the true scope of the invention should no! &s so limited since other modifceattons will become apparent to the skiBed practitioner upon a study of tihe drawings, the specification and the followig claims, 10 GMRfVru A. OP Vji'M PTE i-* AI-- nc, "»..'*• NJ h' .Of Li ■ ol>" CUMMS What is claimed is* 1. A diagnoslte system ramprisln-j: a fu«i Sevel sensor that ssarsses a fuel teve! in a fuel, tank; a sefssar diagnostic mrxM« that activates a fuel transfer mechanism tor ® time period, ttiat calculates a change in said fuel level, and that evaluates operation of said first fuel level sensor based on said esharvge and sa*d predetermined period. 2. The system of claim 1 further comprising an enablement module thai enables said system whs«i said enablemerrt module determines an absence of active faults. X The system of claim 2 wherein said active faults include at least one of component diagnostic trouble cedes, fuel level sensor out of range codes, and vehicle speed fault codes, 4. Tha system of claim 1 further comprising a fuel level detection module that detecss input from ssicj fuel level sensor and a ssoand fuet level sensor wfiertiin said second fuel sensor senses a fuel level of a second fual tank. 11 GM Reference No. GP30BM4-PTE-CD ASlornsy Occket No. S54DP-GGDEC8 5. The system of claim 4 where said fuel level detection module veriSes that said fuel level of said fuel tank exceeds and an empty threshold and said fuel level ai said second fuel tank to below a control threshold. 6. The system of claim 5 wherein said fuel level detection module determine* a first fuel level of said fust tank before activating said fuel transfer mechanism and ctetsBrnirnas a second fuei level of said fuel tank after said time period. 7. The sssxin ut claim 6 wherein said sensor diagnostic modulo deactivates said tcs "am-U- m&chanisjn when said lime period exceeds a time threshold. 8- Trim system of claim 1 wherein said sensor diagnostic module determines a fail slate of said fuel ievfil sensor when said change talis hekw a fuel change threshold and determines a pass state of said fuel level sensor vmm said change exceeds said fuel change threshold. 9. Ths system of stem 8 wtierein said fail operation includes a stuck- irs-range operation. Ct n rf rS jf' 10, A diagnostic method, comprising; sensing a fuel level in s fuel tank;; activating a fuel transfer mechanism for a time period; calculating a change in said fuel tevei; and evaluating operation of a fuel level sensor baaed sn said change end said time period. 11. The method of claim 10 further comprising enabling said method based on determining art absence of active faults.. 12. The method of dum 1t wherein said active faults include at least one of component diagnostic trouble codes, fuel level sensor out of range cooes, and vehicle sp«#d fault codes 13, The method of claim 10 further comprising detecting input from said fuel level sensor and a second fuel level sensor, wherein said fuel level sensor sftnsss said fuel level in said fuel tank and said second fuel level *ens« senses said fuel level of said second fuel tank, 14 The method of claim 13. further comprising verifying thai said fuel liwel of said fuel tank exceeds arid en empty threshold and say fuel level of sakl second fuel tank is below a control threshold. 13 Attorney DGC'.fr" \: bWt, 15. The mathod of claim 14 further comprising determining s first fuel level in said fuel tank before activating said fuel transfer mechanssin arid determining a second fuel level after said time period. 1S. The method of claim 15 further comprising deactivating said foci transfer mechanism when said Sine period of said fuel transfer mechanism exceeds a time threshold. 17, The rrwlhod of claim 10 further comprising determining a fail slate of said fuel level sensor when said change fails below &ase fuel change threshold and determining a pass slate of said fuel level sensor when said change exceeds said fi«l change threshokl 18. The method of claim 17 therein said fell state includes a stuck-irr- rarvge operation. 14 GM Reference No. GP-309394-PTE-CO Attorney Docket N3 8540P-000508 ABSTRACT A diagnostic system and method includes a fuel level sensor that senses a fuel level in a fuel lank and a sensor diagnostic module that monitors a fuel transfer mechanism for a lime period, that calculates a change in the fuel level, and that evaluates operation of the first fuel level sensor baaed on the change and the predetermined period. 15 A diagnostic system and method includes a fuel level sensor that senses a fuel level in a fuel lank and a sensor diagnostic module that monitors a fuel transfer mechanism for a lime period, that calculates a change in the fuel level, and that evaluates operation of the first fuel level sensor baaed on the change and the predetermined period.

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00406-kol-2008-abstract.pdf

00406-kol-2008-claims.pdf

00406-kol-2008-correspondence others.pdf

00406-kol-2008-description complete.pdf

00406-kol-2008-drawings.pdf

00406-kol-2008-form 1.pdf

00406-kol-2008-form 2.pdf

00406-kol-2008-form 3.pdf

00406-kol-2008-form 5.pdf

406-KOL-2008-(19-06-2014)-ABSTRACT.pdf

406-KOL-2008-(19-06-2014)-ANNEXURE TO FORM 3.pdf

406-KOL-2008-(19-06-2014)-CLAIMS.pdf

406-KOL-2008-(19-06-2014)-CORRESPONDENCE.pdf

406-KOL-2008-(19-06-2014)-DESCRIPTION (COMPLETE).pdf

406-KOL-2008-(19-06-2014)-DRAWINGS.pdf

406-KOL-2008-(19-06-2014)-FORM-1.pdf

406-KOL-2008-(19-06-2014)-FORM-2.pdf

406-KOL-2008-(19-06-2014)-OTHERS.pdf

406-KOL-2008-(19-06-2014)-PA.pdf

406-KOL-2008-(19-06-2014)-PETITION UNDER RULE 137.pdf

406-KOL-2008-ASSIGNMENT.pdf

406-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

406-KOL-2008-CORRESPONDENCE OTHERS 1.2.pdf

406-kol-2008-form 18.pdf

406-KOL-2008-PRIORITY DOCUMENT.pdf