Embodiments disclosed herein relate to transmission systems in vehicles and more particularly to the Transmission Control Unit (TCU) in the Automatic transmission system in vehicles.
BACKGROUND
[002] A transfer case is available in vehicles for enabling 4WD (4 Wheel Drive) Low & High Operation of the vehicle. Consider a scenario where one of the axles of the vehicle is on a slippery surface or stuck in mud, whereas the other axle has better traction. In such a scenario, the transfer case can help by transferring torque to the axle(s), which has traction and enabling the vehicle to move.
[003] In a vehicle equipped with an automatic transmission (hereinafter referred to as automatic vehicles), following inputs are required to shift from 4WD high to 4WD low or vice versa (as Shift On-The-Fly is not possible considering the driveline components damage):
- Park/Neutral input from the gearshift lever.
- Vehicle Speed threshold (< 5 Kph) information from 4WD Transfer case
controller Unit (4WD ECU).
[004] This input of Park/Neutral is provided to the Transmission Control Unit (TCU) and the TCU provides this input to the transfer case controller through a hard-wired electrical connection. As the communication is through an electrical wire, there is a possibility of an electrical failure occurring (for example, Ground (GND) Short).
[005] The transfer case controller requires GND to understand that the shift lever is in park/neutral, which enables the 4WD ECU engage the required transfer mode. When the gearshift lever is kept in park/neutral, the TCU receives this information from an inhibitor switch mounted on the transmission and provides the GND signal to the 4WD ECU based on this information. Now, the selector position switch can be moved from 4WD High to 4WD Low or vice-

versa. Subsequently, if the vehicle speed is less than a pre-defined speed, the 4WD ECU allows the engagement of 4WD High to 4WD Low Mode or vice versa. After the engagement is complete, the 4WD ECU also sends the transfer mode engaged information to the vehicle ECU, which in turn communicates to the TCU. The TCU will select the 4WD Low Mode shift map if the changed transfer mode is 4WD Low else no shift map change is done by TCU
[006] Consider a case where the electrical failure (GND Short) occurs in the wiring interface between the TCU and the 4WD ECU. Hence irrespective of the Shift Lever Position, the TCU will always give GND Signal to the 4WD ECU and if the speed condition is also met, then the 4WD ECU engages the transfer modes in all positions even in reverse/drive position.
[007] Feature coding can be used to enable the TCU to switch between 2WD and 4WD to reduce the complexity in maintaining different variants. It is generally written in TCU in Binary language and maximum 3 bytes information can be stored. This maximum size is provided to enable to integrate multiple features/functions. Based on the feature code, the TCU can differentiate whether it is a 2WD or a 4WD vehicle. As this is written at the stand-alone TCU level, there is a possibility that 2WD feature coding is done on a 4WD Vehicle or vice-versa and currently there is no contextual solution available for the TCU to detect this failure and register a Diagnostic Trouble Code (DTC).
OBJECTS
[008] The principal object of embodiments herein is to disclose methods and systems for enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic transmission to detect errors and/or failures.
[009] Another object of embodiments herein is to disclose methods and systems for enabling the TCU in a vehicle equipped with an automatic transmission to detect a GND failure.
[0010] Another object of embodiments herein is to disclose methods and systems for enabling the TCU to detect a GND failure using a feedback system

from a 4WD ECU (Electronic Control Unit) to the TCU and an internal signal from the gear shifter.
[0011] Another object of embodiments herein is to disclose methods and systems for enabling the TCU to register a Diagnostic Trouble Code (DTC), on detecting a GND failure.
[0012] Another object of embodiments herein is to disclose methods and systems for enabling the TCU to identify a wrongly written feature code on the TCU using a feedback system from a vehicle ECU.
[0013] Another object of embodiments herein is to disclose methods and system for enabling the TCU to register a Diagnostic Trouble Code (DTC), on detecting a wrongly written feature code on the TCU.
[0014] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[0015] Embodiments herein are illustrated in the accompanying drawings, through out which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0016] FIG. 1 depicts a system comprising a Transmission Control Unit (TCU) in a vehicle for detecting failures/errors, according to embodiments as disclosed herein;
[0017] FIG. 2 is a flowchart depicting the process of enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic

transmission to detect a GND failure, according to embodiments as disclosed herein; and
[0018] FIG. 3 is a flowchart depicting the process of enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic transmission to detect a wrongly written feature code on the TCU, according to embodiments as disclosed herein

DETAILED DESCRIPTION
[0019] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0020] The embodiments herein achieve methods and systems for enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic transmission to detect failures/errors. Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0021] The vehicle as disclosed herein can be a vehicle equipped with an automatic transmission and four wheel drive (4WD). The 4WD can be selected by a user or can be selected automatically by a control unit present in the vehicle. Examples of the vehicles can be, but not limited to, cars, trucks, Sports Utility Vehicles (SUVs), crossover vehicles, off-roading vehicles, utility vehicles, and so on.
[0022] FIG. 1 depicts a system for enabling the Transmission Control Unit (TCU) in a vehicle to detect failures/errors. The system 100 in a vehicle, as depicted, comprises a TCU 101, a 4WD Electronic Control Unit (ECU) 102, a vehicle ECU 103, an inhibitor switch 104, a gear shifter 105, and a mode selector 106. Examples of the failures/errors can be a GND failure, a wrongly written feature code on the TCU, and so on.

[0023] The TCU 101 and the 4WD ECU 102 can be connected using a hardwired connection. The mode selector 106 and the 4WD ECU 102 can be connected using a hardwired connection. The gear shifter 105 and the inhibitor switch 104 can be connected using a hardwired connection. The inhibitor switch
104 can be connected to the TCU 104 through a hardwired connection. The 4WD
ECU 102 and the Instrument Cluster ECU 103 are connected using a hardwired
connection. The Instrument Cluster 103 can be connected to the TCU 101 using a
Controller Area Network (CAN) bus.
[0024] In an embodiment herein, the gear shifter 105 enables selection of a drive mode (such as drive, park, neutral, reverse, and so on). In an embodiment herein, the gear shifter 105 can be an automatic gear shifter. In an embodiment herein, the gear shifter 105 can be a manual gear shifter, wherein the gear shifter
105 enables selection of gears (such as first, second, and so on) and/or drive
modes (such as reverse, neutral, and so on).
[0025] The inhibitor switch 104 can monitor the current status of the gear shifter 105, as to which drive mode is currently selected. The inhibitor switch 104 can communicate the current status of the gear shifter 105 to the TCU 101 through the hardwired connection.
[0026] The mode selector 106 enables selection of a transfer mode (such as 2WD high, 4WD high, 4WD low, and so on). In an embodiment herein, the mode selector 106 can enable a user to select one or more transfer modes. In an embodiment herein, the mode selector 106 can enable selection of one or more transfer modes automatically, based on one or more pre-defined conditions. The selection of the mode selector 106 can be communicated to the 4WD ECU 102 through the hardwired connection. The 4WD ECU 102 can communicate the current transfer mode status of the mode selector 106 to the Instrument Cluster ECU 103 through the hardwired connection.
[0027] The hardwired connection between the TCU 101 and the 4WD ECU 102 can enable the TCU 101 to provide GND corresponding to park/neutral

position of the gear shifter 105 (received by the TCU 101 from the gear shifter 105, through the inhibitor switch 104) to the 4WD ECU 102.
[0028] The TCU 101 can receive the current status of the transfer mode from the Instrument Cluster ECU 103 through the CAN connection. In an embodiment herein, the Instrument Cluster ECU 103 can communicate the current status of the transfer mode using a CAN signal „TRANSFERMODE‟.
[0029] On the TCU 101 receiving that information from the Instrument Cluster ECU 103, the TCU 101 checks the current position of the gear shifter 105, using inputs from the inhibitor switch 104. If the gear shifter 105 is in reverse or drive position, the TCU 101 determines it as a failure condition (wherein an electrical failure (GND short) has occurred in the hardwired communication link between the TCU 101 and the 4WD ECU 102), transfer mode should not be engaged in reverse and/ drive position. On determining the failure condition, the TCU 101 can provide an indication to a user of the vehicle and/or an authorized service person. The indication can be provided to the user in the form of at least one of an audio means (such as an audible signal), a visual means (such as a failure light in the instrument console and/or infotainment system (for example, gear shift malfunction lamp on the instrument console) and/or a connected device (such as a mobile phone, a tablet, an On-Board Diagnostics (OBD) scanner, and so on), and an audiovisual means. The indication can be provided to the authorized service person in the form of at least one of an email, a SMS (Short Messaging Service), a voice recording, and so on, along with information related to the vehicle. The TCU 101 can further register a Diagnostic Trouble Code (DTC), wherein the DTC can comprise information about the failure, information related to the failure (time stamps, vehicle operating conditions, and so on).
[0030] Feature code information can be stored for a maximum of 3 bytes. The TCU 101 requires only 1 byte to differentiate between 2WD and 4WD drive modes. As shown in the table depicted in Table 1, in byte 1 bit 0 is assigned for the TCU 101 to understand whether the feature code is set or not and bit 1 is assigned for 2WD or 4WD drive modes.


[0031] For a 4WD Vehicle, Feature coding would be written on TCU as follows (Byte 1: Bit 0 as 1 and Bit 1 as 1).
[0032] When the gear shifter 105 is kept in park/neutral, the TCU 101 receives this information from the inhibitor switch 104 and provides the GND signal to the 4WD ECU 102 based on this information.
[0033] The mode selector 106 enables a change in the transfer mode (such as 4WD high to 4WD low, 4WD low to 4WD high, and so on). In an embodiment herein, the mode selector 106 can enable a user to select one or more transfer modes. In an embodiment herein, the mode selector 106 can enable selection of one or more transfer modes automatically, based on one or more pre-defined conditions. The selection of the mode selector 106 can be communicated to the 4WD ECU 102 through the hardwired connection.
[0034] On receiving the communication from the mode selector 106, the 4WD ECU 102 checks the vehicle speed threshold condition and if the vehicle speed is less than a pre-defined sped limit, then the 4WD ECU 102 allows the change in the transfer mode.
[0035] After the change in the transfer mode is complete, the 4WD ECU 102 sends information that the transfer mode has been changed to the Instrument Cluster ECU 103, which in turn communicates to the TCU 101 using a CAN signal „TRANSFERMODE‟. On receiving the communication from the Instrument Cluster ECU 103, the TCU 101 compares this information against the

feature code written on the TCU 101 and if 4WD Feature coding is written on the TCU 101, the TCU 101 will not take any action.
[0036] On receiving the communication from the Instrument Cluster ECU 103, the TCU 101 compares this information against the feature code written on the TCU 101 and if 4WD Feature coding is not written on the TCU 101, the TCU
101 determines it as a failure condition. In an example failure condition, feature
coding for a 4WD vehicle is done as follows for a 2WD vehicle, byte 1: Bit 0 as 1
and Bit 1 as 0. As the change in the transfer mode is not possible for a 2WD
vehicle, the TCU 101 concludes the vehicle is a 4WD vehicle and not a 2WD
vehicle, as indicated in the feature code of the TCU 101.
[0037] On determining the failure condition, the TCU 101 can provide an indication to a user of the vehicle and/or an authorized service person. The indication can be provided to the user in the form of at least one of an audio means (such as an audible signal), a visual means (such as a failure light in the instrument console and/or infotainment system (for example, gear shift malfunction lamp on the instrument console) and/or a connected device (such as a mobile phone, a tablet, an On-Board Diagnostics (OBD) scanner, and so on), and an audiovisual means. The indication can be provided to the authorized service person in the form of at least one of an email, a SMS (Short Messaging Service), a voice recording, and so on, along with information related to the vehicle. The TCU 101 can further register the DTC, wherein the DTC can comprise information about the feature code, information related to the feature code (time stamps, current feature code, the required feature code, and so on).
[0038] In an embodiment herein, the CUs (the TCU 101, the 4WD ECU
102 and the Instrument Cluster ECU 103) can be independent modules, which are
connected to each other and performing specific functions (as disclosed in
embodiments herein). In an embodiment herein, two or more of the CUs can be
integrated with each other. In an example, the TCU 101 and the Instrument
Cluster ECU 103 can be integrated together wherein the integrated CUs perform
the functions as performed by the TCU 101 and the Instrument Cluster ECU 103,

as disclosed herein. In an example, the TCU 101 and the 4WD ECU 102 can be integrated together wherein the integrated CUs perform the functions as performed by the Instrument Cluster ECU 103 and the 4WD ECU 102, as disclosed herein. In an example, the Instrument Cluster ECU 103 and the 4WD ECU 102 can be integrated together wherein the integrated CUs perform the functions as performed by the Instrument Cluster ECU 103 and the 4WD ECU 102, as disclosed herein. In an example, the TCU 101, the Instrument Cluster 103 and the 4WD ECU 102 can be integrated together wherein the integrated CUs perform the functions as performed by the TCU 101, the Instrument Cluster ECU 103 and the 4WD ECU 102, as disclosed herein.
[0039] FIG. 2 is a flowchart depicting the process of enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic transmission to detect a GND failure. On detecting (201) a change in the mode selector 106 (which can be done either manually or automatically) (wherein the change can be a change in transfer mode), the 4WD ECU 102 sends (202) a signal to the vehicle ECU 103 through the hardwired connection, wherein the signal indicates the change in the mode selector 106. The Instrument Cluster ECU 103 communicates (203) the signal to the TCU 101 over the CAN bus. On the TCU 101 receiving that information from the Instrument Cluster ECU 103, the TCU 101 checks (204) the current position of the gear shifter 105, using inputs from the inhibitor switch 104. If the gear shifter 105 is not in park or neutral position, the TCU 101 determines (205) it as a first failure condition (wherein an electrical failure (GND short) has occurred in the hardwired communication link between the TCU 101 and the 4WD ECU 102), transfer mode should not be engaged in park and/or neutral position. On determining the failure condition, the TCU 101 provides (206) an indication to a user of the vehicle and/or an authorized service person. The TCU 101 further registers (207) the Diagnostic Trouble Code (DTC). If the gear shifter 105 is in park or neutral position, the TCU 101 does (208) not take any corresponding action. The various actions in method 200 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 2 may be omitted.

[0040] FIG. 3 is a flowchart depicting the process of enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic transmission to detect a wrongly written feature code on the TCU. On detecting (301) a change in the mode selector 106 (which can be done either manually or automatically) (wherein the change can be a change in transfer mode from 4WD to 2WD or vice versa), the 4WD ECU 102 sends (302) a signal to the vehicle ECU 103 through the hardwired connection, wherein the signal indicates the change in the mode selector 106. The Instrument Cluster ECU 103 communicates (303) the signal to the TCU 101 over the CAN bus. On the TCU 101 receiving that information from the vehicle ECU 103, the TCU 101 compares (304) this information against the feature code written on the TCU 101. If the feature coding does not match (i.e., the feature code written on the TCU 101 indicates that the vehicle is a 2WD), the TCU 101 determines (305) it as a second failure condition (wherein the wrong feature code is written in the TCU 101). On determining the failure condition, the TCU 101 provides (306) an indication to a user of the vehicle and/or an authorized service person. The TCU 101 further registers (307) the Diagnostic Trouble Code (DTC). If the feature code matches, the TCU 101 does (308) not take any corresponding action. The various actions in method 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 3 may be omitted.
[0041] Embodiments herein provide an improvement in safety. Embodiments herein enable avoidance of failure scenarios, by enabling the customer to become aware of the failure and avoid running of the vehicle for a prolonged time leading to the driveline components damage and hereby avoiding the breakdown of the vehicle.
[0042] Embodiments herein enable the user and the service personal to identify the cause of the failure and take appropriate corrective actions (such as replacing the wiring harness/correcting the wiring harness, and so on).
[0043] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and

performing network management functions to control the network elements. The elements shown in FIG. 1 include blocks, which can be at least one of a hardware device, or a combination of hardware device and software module.
[0044] The embodiment disclosed herein describes methods and systems for enabling the Transmission Control Unit (TCU) in a vehicle equipped with an automatic transmission to detect a GND failure. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in at least one embodiment through or together with a software program written in e.g. Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device may also include means which could be e.g. hardware means like e.g. an ASIC, or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g. using a plurality of CPUs.
[0045] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments

herein have been described in terms of embodiments and examples, those skilled in the art will recognize that the embodiments and examples disclosed herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

STATEMENT OF CLAIMS
We claim:
1. A system (100) in a vehicle equipped with an automatic transmission
comprising
a Transmission Control Unit (TCU) (101) configured for checking if a gear shifter (105) is in at least one of park mode or neutral mode, on receiving communication about change in the mode selector (106) from a Four Wheel Drive (4WD) Electronic Control Unit (ECU) (102) via a vehicle ECU (103);
determining a first failure condition if the gear shifter (105) is not in at least one of park mode or neutral mode, wherein the first failure condition is an electrical failure (GND short) in the hardwired communication link between the TCU (101) and the 4WD ECU (102); and
registering a Diagnostic Trouble Code (DTC).
2. The system, as claimed in claim 1, wherein the system further comprises
the 4WD ECU (102) configured for communicating a change in a mode selector (106) to the vehicle ECU (103) through a hardwired connection; and
the vehicle ECU (103) configured for communicating the change in the mode selector (106) to the TCU (101) using a Controller Area Network (CAN).
3. The system, as claimed in claim 2, wherein the Instrument Cluster ECU (103) is configured for communicating the change in the mode selector (106) to the TCU (101) using a „TRANSFER_MODE‟ CAN signal.
4. The system, as claimed in claim 1, wherein the system further comprises an inhibitor switch (104) configured for communicating current status of the gear shifter (105) to the TCU (101) through a hardwired connection.
5. The system, as claimed in claim 1, wherein the TCU (101) is configured for providing an indication to at least one of a user of the vehicle; and an authorized service person.

6. A method for detecting a failure condition in a vehicle equipped with an
automatic transmission comprising
checking if a gear shifter (105) is in at least one of park mode or neutral mode by a Transmission Control Unit (TCU) (101), on receiving communication about change in the mode selector (106) from a Four Wheel Drive (4WD) Electronic Control Unit (ECU) (102) via a Instrument Cluster ECU (103);
determining a failure condition by the TCU (101), if a gear shifter (105) is not in at least one of park mode or neutral mode, wherein the failure condition is an electrical failure (GND short) in the hardwired communication link between the TCU (101) and the 4WD ECU (102); and
registering a Diagnostic Trouble Code (DTC) by the TCU (101).
7. The method, as claimed in claim 6, wherein the method further comprises
communicating a change in a mode selector (106) to the vehicle ECU (103) by the 4WD ECU (102) through a hardwired connection; and
Communicating the change in the mode selector (106) to the TCU (101) by the vehicle ECU (103) using a Controller Area Network (CAN).
8. The method, as claimed in claim 7, wherein the Instrument Cluster ECU (103) communicates the change in the mode selector (106) to the TCU (101) using a „TRANSFERMODE‟ CAN signal.
9. The method, as claimed in claim 6, wherein an inhibitor switch (104) communicates current status of the gear shifter (105) to the TCU (101) through a hardwired connection.

10. The method, as claimed in claim 6, wherein the TCU (101) provides an indication to at least one of a user of the vehicle; and an authorized service person.
11. A system (100) in a vehicle comprising
a Transmission Control Unit (TCU) (101) configured for

checking if a feature code written on the TCU (101) matches a feature code for a 4WD vehicle, on receiving communication about change in the mode selector (106) from a Four Wheel Drive (4WD) Electronic Control Unit (ECU) (102) via a Instrument Cluster ECU (103);
determining a second failure condition, if the feature code written on the TCU (101) does not matches a feature code for a 4WD vehicle; and
registering a Diagnostic Trouble Code (DTC).
12. The system, as claimed in claim 11, wherein the system further comprises
the 4WD ECU (102) configured for communicating a change in a mode selector (106) to the vehicle ECU (103) through a hardwired connection; and
the vehicle ECU (103) configured for communicating the change in the mode selector (106) to the TCU (101) using a Controller Area Network (CAN).
13. The system, as claimed in claim 12, wherein the Instrument Cluster ECU (103) is configured for communicating the change in the mode selector (106) to the TCU (101) using a „TRANSFER_MODE‟ CAN signal.
14. The system, as claimed in claim 11, wherein the TCU (101) is configured for providing an indication to at least one of a user of the vehicle; and an authorized service person.
15. A method for detecting a failure condition in a vehicle comprising
checking if a feature code written on a Transmission Control Unit (TCU) (101) matches a feature code for a 4WD vehicle by the TCU (101), on receiving communication about change in the mode selector (106) from a Four Wheel Drive (4WD) Electronic Control Unit (ECU) (102) via a vehicle ECU (103);
determining a second failure condition by the TCU (101), if the feature code written on the TCU (101) does not matches a feature code for a 4WD vehicle; and
registering a Diagnostic Trouble Code (DTC) by the TCU (101).

16. The method, as claimed in claim 15, wherein the method further comprises
communicating a change in a mode selector (106) to the Instrument Cluster ECU (103) by the 4WD ECU (102) through a hardwired connection; and
communicating the change in the mode selector (106) to the TCU (101) by the vehicle ECU (103) using a Controller Area Network (CAN).
17. The method, as claimed in claim 16, wherein the Instrument Cluster ECU (103) communicates the change in the mode selector (106) to the TCU (101) using a „TRANSFERMODE‟ CAN signal.
18. The method, as claimed in claim 15, wherein the method further comprises providing an indication by the TCU (101) to at least one of a user of the vehicle; and an authorized service person.