SE1650116A1 - Fault Codes in a motor vehicle - Google Patents

Abstract

An electronic control system (1) for a motor vehicle, and a method of monitoring a motor vehicle performed by an electronic control system (1) of the motor vehicle is provided. The method includes detecting (101, 107) faults, registering (102, 108) a fault code in a register upon detecting (101) a fault, which registering includes indicating that the fault is active, and inactivating (103, 109) the fault code in connection with a removal, or disappearance, of the fault. Especially, said monitoring includes registering (102, 108) of fault codes both during use of the motor vehicle and during repair of the motor vehicle, wherein the registering (108) of a fault code during repair includes indicating that the fault appeared during repair. In this way, faults appearing as a consequence of a repair action may be identified in the register and distinguished from faults appearing during use.

Description

Fault Codes in a motor vehicle Technical Field The invention relates to an electronic control system for a motorvehicle and a method of monitoring a motor vehicle. Especially,the electronic control system and the method relates to theregistration of fault codes in such an electronic control system.

Background lt has become common to utilize electronic control systems inmodern land motor vehicles in order to control the functioning ofthe motor vehicle and its equipment. The electronic controlsystem controls devices and systems of the motor vehicle, andmay for example control devices and systems such as theelectric system, engine, transmission line, braking system,gearbox, combustion system, navigation system, safetyfeatures, driver utilities etc. The electronic control system oftenincludes a communication bus that communicativelyinterconnect electronic control units (ECUs) of the electroniccontrol system, which ECUs are further connected to sensors,measurement devices and components of the motor vehicle.Such electronic control systems utilize measurements andstatus indications for controlling the functions of the motorvehicle and its components. One function of the electroniccontrol system is to detect faults or malfunctions of the motorvehicle, components and equipment, wherein the electroniccontrol system detects faults and perform safety functions in themotor vehicle.

The present invention relates to the storing of fault codes in anelectronic control system of a land motor vehicle, such as a car,a truck or a bus. Known electronic control systems monitor thefunctioning of components of the vehicle and generate and storefault codes when something is malfunctioning. The fault codesmay be used by a safety system of the electronic control systemfor performing safety functions when the motor vehicle is used.

The fault codes may also be retrieved and used by a mechanicin a workshop for performing a diagnosis of the motor vehicle inorder to repair the motor vehicle.

The US patent document US 2008/0161994 ('994) brieflydescribes some electronic control systems that uses fault codes(see §OOO3-§0OO9 in '994). Such electronic control systems isprovided to generate and store fault codes in a table format, andthe fault codes may be read out by means of external computerdevices upon repairing a faulty vehicle. The document '994especially concerns generating a table of fault codes in ahumanly readable format, see §OO1O of '994, which table ispresented on a service tool. A fault condition status is indicatedas a flag at each fault code, see §OO17, §O019 in '994. Theelectronic control system controls the vehicle on the basis of thefaults when the faults appear. After service, the system may bereset, see §OO21 in '994.

By deleting a flag that indicates that a fault code is active, thetable will indicate that the fault code has been deactivated, i.e. afault of the motor vehicle has been repaired. However, duringrepair or service of the motor vehicle, ECUs, components orother parts of the motor vehicle may be removed, which maylead to the generation of further fault codes. These fault codeswill then indicate that something has been malfunctioning andsubsequently been repaired even though there actually was nofault of the motor vehicle, since the fault codes only appearedas a consequence of a repairing or service action. lndications ofearlier faults, such as fault codes created during service orrepair, may be interpreted during a following service or repair asan indication of an earlier fault of the motor vehicle. Theseindications may lead a mechanic to believe some componenthas been malfunctioning, or may make diagnosis of the motorvehicle more difficult, and may lead to unnecessary replacementof fully operable components of the motor vehicle.

Summary of inventionAn aim of the present invention is to remove or at least alleviatethe shortcomings of the prior art. ln a first aspect, the present invention provides an electroniccontrol system for a motor vehicle. The electronic control systemcomprises a controller, at least one electronic control unit, atleast one sensor, and a communication means connecting saidelectronic control unit and/or said sensor to the controllerwherein the electronic control system is configured to transferinformation indicative of faults of the motor vehicle from saidelectronic control unit and/or said sensor to the controller, andwherein the controller comprises a register for registering faultcodes indicative of faults and is configured to register a faultcode together with a status of the corresponding fault whichstatus indicates that the fault is either active or inactive.Especially, the controller is further configured to indicate in saidregister whether a fault code is registered during repair of themotor vehicle.

Such a registration is valuable since fault codes generatedduring a repair or service of the motor vehicle may not relate toan actual fault, but may be initiated by a normal repair or serviceaction. By performing registration of fault codes also duringrepair, the fault codes can be used for safety purposes duringthe repair. Safety functions that rely on fault codes and that arealready present in the electronic control system may continue tofunction properly. ln an embodiment of the first aspect, the electronic controlsystem comprises means for communicative connection to anexternal computer device, for example a device for displayingthe fault codes to a mechanic, wherein the controller isconfigured to enter a repair mode upon connection to theexternal computer device, which repair mode comprisesregistering fault codes as registered during repair.

Preferably, the controller is configured to exit the repair modeupon disconnection from the external computer device, andsubsequently register fault codes without indicating repair of themotor vehicle. ln an embodiment of the first aspect the electronic controlsystem comprises means for performing safety functions basedon the fault codes, which means for performing safety actionsare kept active during the repair mode. ln an embodiment of the first aspect, the electronic controlsystem is configured for manual deactivation of at least one ofthe fault codes and/or to automatically deactivate at least one ofthe fault codes following a function test.

According to a second aspect, the present invention provides amethod of monitoring a motor vehicle, which method isperformed by an electronic control system of the motor vehicle.The method comprises: - detecting faults, - registering a fault code in a register upon detecting a fault,which registering includes indicating that the fault is active.

The method further comprises inactivating the fault code inconnection with a removal, or disappearance, of the fault.Especially, said method of monitoring comprises performing theregistering of fault codes both during use of the motor vehicleand during repair of the motor vehicle, wherein the registering ofa fault code during repair includes indicating that the faultappeared during repair.

An embodiment of the second aspect, includes: - detecting connection, and disconnection, of the electroniccontrol system to, and from, an external computer device, - entering a repair mode upon detecting connection to theexternal computing device, and - exiting the repair mode upon detecting disconnection from theexternal computing device, in order to determine when repair isperformed and indicate that the fault code appeared duringrepair.

The method may alternatively, or additionally, allow manualtransfer between a first and second mode of operation, i.e. toand from the repair mode, performed for example by a mechanicat a workshop. ln an embodiment of the second aspect, the inactivating of atleast one fault code, of the fault codes, is performed uponperforming a functioning test and/or upon receiving a manualinput from a user.

Brief Description of the Drawings The invention will now be described in exemplary embodimentswith reference to the accompanying drawings, wherein: Figure 1 illustrates an embodiment of parts of an electroniccontrol system 1 of a motor vehicle for the purposes offacilitating implementation the present invention; Figure 2 is a table illustrating a fault code register in accordancewith an embodiment of the present invention; Figure 3 is a flow chart illustrating an embodiment of monitoringand registering actions performed in accordance with thepresent invention.

Figure 4 is a flow chart illustrating a further embodiment of theembodiment of figure 3.

Detailed Description Figure 1 illustrates an embodiment of a part of an electroniccontrol system 1 for a motor vehicle, especially a land motorvehicle (not illustrated). The electronic control system 1comprises a controller 2, a number of electronic control units,ECUs, 3, sensors 4, electronic components 5 and acommunication bus 6. The controller 2 is communicatively connected by means of the communication bus 6 to each ECU 3.Each ECU is connected to one or more sensor 4 and/or acomponent 5. The controller 2 may also be directly connected toa sensor 4. An ECU 3 may for example be provided forcontrolling a specific device or system, such as the gear box orthe braking system, and may be connected to all thecomponents 5 of the specific device or system and the sensors4 arranged at that specific device or system. The controller 2 inthe illustrated embodiment of figure 1 is also connected to acommunication means 7 for communicating with an externalcomputer device 10, such as a PC used at a workshop used fordiagnosis, service and repair of the motor vehicle. Thecommunication means 7 may be a physical contact for cableconnection to the external computer device, but mayalternatively be, or also include, a wireless communication unit.

The controller 2 comprises a register 21 for registering faultsand is configured to receive fault codes from the other devices,especially the ECUs 3 and register the fault codes in the register21. The controller 2 may also be configured to create fault codesby determining, e.g. from information received from the ECUs 3and/or sensors 4, that one or more components 5 of the motorvehicle is malfunctioning. The controller 2 also includes means22 for performing safety actions, which means 22 for performingsafety actions is configured to take action based on faults thatoccur, as indicated by the fault codes in the register 21. Thecontroller 2 may for example be provided as an electroniccontrol unit, and the register 21 and the means 22 forperforming safety actions may be provided as software forcontrolling the electronic control unit, i.e. the controller 2. ln theillustrated embodiment, the means 22 for performing safetyactions is illustrated as a single unit within the controller 2, butthe functions of the means 22 for performing safety actions mayhowever be distributed among several ECUs 3 of the electroniccontrol system 1. For example an ECU controlling the gear boxmay be provided with safety function not allowing gear shift selections in response to a specific fault code, or an ECU 3controlling an internal combustion engine may be provide withsafety functions to not allow start of the engine in response toone or more specific fault codes stored in the register 21.

The controller 2 is configured to detect connection to theexternal computer device 10, and configured to store fault codesin the register 21 in differing ways in view of the electroniccontrol system 1 being connected to the external computerdevice 10 or not. The controller 2 is configured to register faultcodes in the register 21 in accordance with a first mode whenthe electronic control system 1 is not connected to the externalcomputer device 10 and in accordance with a second mode, arepair mode, when the electronic control system 1 is connectedand communicates with the external computer device 10. Uponconnecting an external computer device 10 the controller 2 maybe configured to perform a handshake action, such as includingan indication of identity and/or an indication of repair. Theconnection may be configured for automatic transfer of a repairindication from an external computer device 10 of a workshop tothe controller 2, and/or the controller 2 may be configured forreceiving a repair mode signal that is manually initiated by amechanic.

Figure 2 illustrates an embodiment of the register 21 of thecontroller 2. The register 21 is illustrated in table format,wherein the first column is utilized by the controller 2 forentering a fault code for each occurring fault. The secondcolumn is used by the controller 2 to indicate whether the fault isactive or not, i.e. the status of the fault. Thus, when a faultoccur the controller 2 registers the fault code of the fault in thefirst column and indicates that the fault is active in the secondcolumn, e.g. flagging the fault code by a status indication suchas a When the fault disappears, e.g. a faulty component isrepaired or exchanged, the controller 2 is configured to inactivate the fault code by changing the status in column 2, forexample from a “1 ” to a The table illustrating the register 21 also includes a third columnprovided for registering whether the fault appeared during repairor not, and the controller 2 is configured to indicate whether thefault appeared during repair of not in the register 21 by meansof setting a flag, for example “1” when registering a fault codeduring repair and with a “0” when registering a fault code duringuse of the motor vehicle, i.e. when not connected to an externalcomputer device 10. The controller 2 may be configured to notalter the repair mode indication when the fault disappears,merely deactivate the fault code, and is thus configured topermanently store the repair mode indication in the register 21.The indication of a repair mode gives valuable information toservice and repair personnel, and by keeping the fault coderegistration active during repair also enables the safety actionsperformed by the means 22 for performing safety actions activeduring a repair or service. Thus, the electronic control system 1can be allowed to continue functioning as when the motorvehicle is in use also during repair, and fault codes reflectingrepair rather than faults can be easily identified in the register21. The controller 2 may be configured to delete fault codesupon receiving a command for deleting fault codes, especiallyfault codes indicated during the repair mode.

Figure 3 illustrates an embodiment of the monitoring andregistering functions of the controller 2 of the electronic controlsystem 1 of figure 1 as a flow chart. The controller 2 is providedto detect faults 101, 107, register 102, 108 fault codes in theregister 21, and inactivate fault codes 103, 109 in the register,e.g. changing the status flag from active, to inactive, The controller 2 is also configured to change (104, 110) from thefirst operating mode to the second operating mode, i.e. therepair mode, upon determining 104 that the electronic controlsystem is connected to the external computer device 10 and upon determining 110 that the electronic control system 1 isdisconnected from the external computer device 10,respectively. The functions of detecting 101, 107, registering102, 108 and inactivating 103, 108 is performed continuouslythrough the monitoring process 100, and is only illustrated assteps performed in specific order for illustrative purposes ofunderstanding the invention. The steps of determiningconnection 104 and disconnection 110, wherein the operatingmode is changed between the first mode and the second repairmode affects how the controller 2 performs the steps ofregistration 102, 108.

The illustrated method of monitoring 100 the motor vehicleincludes detecting, or determining, a fault. Registering 102 thefault by means of entering a fault code in the register 21together with a status indication, indicating active, andindicating that the fault did not appear during repair or service.The method further includes inactivating 103 a fault code bychanging status from active to inactive when a fault disappear.The method further includes determining 104 if the motor vehicleis being connected to an external computer device 10, and if soentering 105 the second mode, i.e. the repair mode. The repairmode includes communicating 106 with the external computerdevice 10, especially transferring the register 21 to the externalcomputer device 10, and continuing to detect 107 faults, registerfaults 108 and inactivate 109 fault codes when the faults areremoved during the repair. The step of registering 108 faultcodes performed in the repair mode includes indicating in theregister 21 that the fault appeared during repair, as exemplifiedby indicating a ”1” in the register 21 in accordance with the tableof figure 2. The repair mode of the monitoring method 100 alsoincludes determining 110 when the motor vehicle becomesdisconnected from the external computer device 10 whereuponthe method includes exiting 111 the repair mode and returningto detecting faults 101, registering faults 102 and inactivatingfault codes 103 and monitoring the connection to the external computer device in accordance with the first operating mode.Otherwise, the repair mode continues with communicating 106with the external computer device, detecting/determining faults107, registering 108 fault code including status active andduring repair, and with inactivating 109 faults that disappear orare removed during the repair.

The inactivation 103, 109 of fault codes may be subjected torequirements or restrictions in a variety of ways. The controller 2may be configured for both manual and automatic inactivation103, 109 of fault codes. The controller 2 may be configured toonly allow inactivation of some, and not all, faults followingperformance of a function test. Thus, for some faults, thecontroller 2 may be configured to allow manual inactivation of afault code only after performance of a successful function test ofthe system or component in question. The controller 2 may alsobe configured for automatic inactivation of some fault codesfollowing a successful function test.

Upon exiting 111 the repair mode, the method may include astep of clearing 112 fault codes or fault code status indications.For example, the controller 2 may be configured to clear 112fault codes that appeared during repair and that are inactiveduring exiting 111 of the repair mode. Furthermore, thecontroller 2 may be configured for clearing fault codeindications, so that the step of clearing 112 includes clearingrepair mode indication for faults that are still active after therepair.

Figure 4 illustrate a further embodiment of the method of figure3, wherein upon connection 104 of an external computer device10 the method includes a step of selecting 114 whether or not toenter the repair mode. Such a selection 114 step is valuable,since for example a mechanic or service personnel may connectthe electronic control system 1 of the motor to an externalcomputer device 10 in order to perform one or more function 11 tests of the motor vehicle. Thus, the external computer device10 may be connected in order to co||ect data during a test inorder to perform a diagnosis, or in order to test, such as drive,the motor vehicle after a repair. The embodiment of figure 4illustrates similar steps of the repair mode as in figure 3,including entering 105 repair mode, communicating 106 faultcodes, detecting 107 faults, registering 108 fault codes with arepair indication, inactivating 109 fault codes upon repair,exiting 111 repair mode, and clearing 112 fault codes and/orfault code 112 indications. The repair mode of figure 4 includesan additional step of selectively exiting 115 repair mode andentering a third mode of operation when connected to anexternal computer device 10. The third mode of operation isexemplified as a test mode, during which third mode theelectronic control system 1 of the motor vehicle is connected toan external computer device. Exiting 115 the repair mode maybe performed upon receiving a command initiated from a user,e.g. mechanic.

The third mode includes communicating 116 fault codes, uponentering, and may repeat this step 116 automatically or uponcommand from the external computer device 10, e.g. ascontrolled by the mechanic. The step of communicating 116 faultcodes in the third mode is similar or identical to the step ofcommunicating 106 fault codes in the repair mode/second mode.The third mode also includes detecting faults 117, registeringfaults 118, an inactivating 119 faults, which steps may beperformed in the same way as the detection of faults 101, theregistration of faults 102, and inactivating 103 of faultsperformed during use, i.e. in the first mode. The difference fromnormal use being the communicating 116 of fault codes to theexternal computer device and the step of selective entering 114into the repair mode without disconnecting (step 120) from theexternal computer device 10 and the returning to the first modeupon disconnection, step 120, from the external computerdevice. Thus, the test mode or third mode includes a step of 12 determining 120 disconnection from the external computerdevice. lf not disconnected, the third mode is repeated, but mayselectively enter 114 the repair mode. lf disconnection isdetermined 120, the third mode may include a step of clearing112, e.g. clearing inactive fault codes for faults appearing duringrepair, or clearing repair mode indication for faults still activeafter disconnection 120 from the external computer device. Afterdisconnection, the electronic control system returns to the firstmode of operation, i.e. the method of monitoring continues inthe first mode.

The controller 2 may also be configured to inactivate some faultcodes after manual instructions from a user, such as amechanic, without performance of a function test. Thus, thecontroller 2 may be adapted for a variety of further controlfunctions regarding inactivation of fault codes without deviatingfrom the scope of the present invention. The selection of whichfault codes that should require function tests, or not, should bethe object of manual and/or automatic removal is however not aspecific feature of the present invention.

An electronic control system (1) for a motor vehicle, and amethod of monitoring a motor vehicle performed by an electroniccontrol system (1) of the motor vehicle has been provided inembodiments. The method includes detecting (101, 107) faults,registering (102, 108) a fault code in a register upon detecting(101) a fault, which registering includes indicating that the faultis active, and inactivating (103, 109) the fault code in connectionwith a removal, or disappearance, of the fault. Especially, saidmonitoring includes registering (102, 108) of fault codes bothduring use of the motor vehicle and during repair of the motorvehicle, wherein the registering (108) of a fault code duringrepair includes indicating that the fault appeared during repair.ln this way, faults appearing as a consequence of a repair actionmay be identified in the register and distinguished from faultsappearing during use. The present invention is however not 13 restricted to these embodiments but may be varied within thescope of the claims.

The functions of the electronic control system and themonitoring method described, of figures 1 to 4, may be providedby means of a computer-readable media, such as a computerprogram product installable in an electronic control system 1 ofa motor vehicle. Such a computer program product may beprovided in a non-transitory memory, such as a computer disc, ahard disc or a flash memory. The computer program productmay be transferred from a first non-transitory memory to asecond non-transitory memory, which second non-transitorymemory is provided in an electronic control system of a motorvehicle, and which transfer may include a transitory signal, suchas a signal transferred by means of Internet, a cable and/or awireless connection. The expression “non-transitory” computer-readable media should be interpreted as all computer-readablemedia, with the sole exception being a transitory, orpropagating, signal.

Figure 5 illustrate a first non-transitory memory 51, and asecond non-transitory memory 52 of a motor vehicle wherein acomputer program product 55 stored in the first non-transitorymemory 51 is transferred via Internet 53 to, and stored in, thesecond non-transitory memory 52. Figure 5 also illustrate acomputer program product 55 for providing the presentinvention, which is stored in a computer disc 54. The computerprogram 55 of the computer disc 54 may be transferred directlyto the electronic control system 1 or via an external computerdevice 10.

The present invention primarily concerns land motor vehicles,such as cars, buses, trucks, motor cycles, but may also beimplemented in other motor vehicles, such as boats, ships or forexample airplanes.

Claims (12)

14 Claims

1. Electronic control system (1) for a motor vehiclecomprising a controller (2), at least one electronic control unit(3), at least one sensor (4), and a communication means (6)connecting said electronic control unit (3) and/or said sensor (4)to the controller (2), wherein the electronic control system (1) isconfigured to transfer information indicative of faults of themotor vehicle from said electronic control unit (3) and/or saidsensor (4) to the controller (2), and wherein the controller (2)comprises a register (21) for registering fault codes indicative offaults and is configured to register a fault code together with astatus of a corresponding fault which status indicates that thefault is either active or inactive, c h a r a c t e r i z e d in thatthe controller (2) is further configured to indicate in said register(21) whether a fault code is registered during repair of the motorvehicle.

2. Electronic control system according to claim 1, wherein theelectronic control system (1) comprises means (7) forcommunicative connection to an external computer device (10),wherein the controller (2) is configured to enter a repair modeupon connection to the external computer device (10), whichrepair mode comprises registering fault codes as registeredduring repair.

3. Electronic control system according to claim 2, wherein thecontroller (2) is configured to exit the repair mode upondisconnection from the external computer device (10), andsubsequently register fault codes without indicating repair of themotor vehicle.

4. Electronic control system according to any of claims 1 to 3,wherein the electronic control system (1) comprises means (22)for performing safety functions based on the fault codes, which means for performing safety actions are kept active during therepair mode.

5. Electronic control system according to any of c|aims 1 to 4,wherein the electronic control system (1) is configured formanual deactivation of at least one of the fault codes and/or toautomatically deactivate at least one of the fault codes followinga function test.

6. A method of monitoring a motor vehicle performed by anelectronic control system (1) of the motor vehicle, said methodcomprising: - detecting (101, 107) faults, - registering (102, 108) a fault code in a register upon detecting(101) a fault, which registering includes indicating that the faultis active, and wherein the method further comprises: - inactivating (103, 109) the fault code in connection with aremoval, or disappearance, of the fault, said method ofmonitoring is c h a r a c t e r i z e d in performing theregistering (102, 108) of fault codes both during use of themotor vehicle and during repair of the motor vehicle, wherein theregistering (108) of a fault code during repair includes indicatingthat the fault appeared during repair.

7. A method of monitoring a motor vehicle according to claim6, including: - detecting connection (104), and disconnection (110), of theelectronic control system (1) to, and from, an external computerdevice (10), - entering (105) a repair mode upon detecting connection (104)to the external computing device (10), and - exiting (111) the repair mode upon detecting disconnection(108) from the external computing device (10), in order todetermine when repair is performed and indicate that the faultcode appeared during repair. 16

8. A method of monitoring a motor vehicle according to claim6 or 7, wherein inactivating (103, 109) of at least one of the faultcodes is performed upon performing a functioning test and/orupon receiving a manual input from a user.

9. A motor vehicle comprising an electronic control system(1) in accordance with any of claims 1 to 5, and/or comprisingan electronic control system configured to perform the methodaccording to any of claims 6 to 8.

10. A computer program (55) which when executed by anelectronic control system 1 of a motor vehicle enables theelectronic control system to perform the method of monitoringaccording to any of claims 6 to 9.

11. A computer program product (54) comprising a computerprogram in accordance with claim 10, which computer program(55) is stored in a non-transitory memory (54).

12. Method of installing a computer program (55) inaccordance with claim 10 in an electronic control system 1 of amotor vehicle comprising transferring the computer program (55)from a non-transitory memory (51, 54) located outside the motorvehicle into a non-transitory memory (52) located in theelectronic control system 1.