A fault diagnosis method, a thermal management device, a medium, a thermostat and a controller

Abstract

The present application belongs to the technical field of thermal management, and particularly relates to a fault diagnosis method, a thermal management device, a medium, a thermostat and a controller; by actively intervening in the thermal management process, a controllable observation window is provided for fault diagnosis, which is conducive to avoiding interference caused by related heat exchange units, and ensures the effectiveness and reliability of diagnosis; based on the existing heat exchange topology structure and the engine management system (EMS) hardware, without increasing additional components and integrating the diagnosis process (333), the risk of misdiagnosis is eliminated; the initial conditions and disturbance factors of the working conditions in the comprehensive diagnosis are calibrated through the threshold, and adaptive switching of the diagnosis or detection process is realized; by configuring the system priority, the coexistence of the existing system and the present application is ensured, and the safety and applicability of system modification are improved; on the basis of ensuring the existing functions of the engine (010) system, the fault diagnosis capability of the thermostat (906), the controller (901) and the like is improved.

Description

Technical Field

[0001] This invention belongs to the field of thermal management technology, and particularly relates to a fault diagnosis method, thermal management device, medium, thermostat and controller. Background Technology

[0002] The thermostat is one of the core components of a vehicle's thermal management system. Its reliable operation is crucial for vehicle emission control and fuel consumption. Relevant standards and regulations have also added corresponding diagnostic requirements to standardize and improve the overall technical level in this field.

[0003] However, with the upgrading of engines and the iterative development of engine thermal management systems, electronic thermostats need to cope with more potential changes in operating conditions in order to ensure that they achieve the same excellent user experience in more application scenarios and at the same time ensure that the thermal management system operates at a good operating point.

[0004] like Figure 1 , Figure 2 , Figure 3 , Figure 3 The image shows a typical thermal management system structure and related fault diagnosis data in the relevant technology. Among them, the fault diagnosis of the thermostat often faces the problem of misdiagnosis, which seriously affects the stable operation of the engine. Therefore, it is urgent to improve the relevant fault diagnosis methods. Summary of the Invention

[0005] This invention discloses a fault diagnosis method, including a third active intervention step. This third active intervention step responds to a duty cycle limitation request and executes a preset diagnostic process. When responding to the duty cycle limitation request, the output power of the drive unit is limited to a range less than or equal to a ninth duty cycle threshold C9. The drive unit provides power for the heat exchange medium to circulate in a preset heat exchange channel. The heat exchange channel further includes at least one of a first heating heat exchange unit, a second valve unit, a third cooling heat exchange unit, a fourth medium buffer unit, a sixth cooling heat exchange unit, a seventh heating heat exchange unit, and an eighth cooling heat exchange unit. Furthermore, under the excitation of the drive unit, the heat exchange channel intervenes in the heat exchange process using the fluid medium inside the heat exchange channel, thereby enabling the aforementioned diagnostic process to be achieved.

[0006] The diagnostic process includes diagnosing leakage faults in the second valve unit; specifically, the diagnostic process may employ a dual-temperature diagnostic method; its first heating heat exchange unit obtains heat from the vehicle engine.

[0007] Furthermore, its second valve unit can be a valve unit in a thermostat; its third cooling heat exchange unit can be a radiator of an engine; its fourth medium buffer unit is used to provide space for thermal expansion and contraction, medium replenishment and monitoring of the fluid medium inside the heat exchange channel; its heat exchange channel includes a large circulation passage with the aforementioned radiator, a small circulation passage shortly connected to its radiator and a third passage of the sixth cooling heat exchange unit, the seventh heating heat exchange unit and / or the eighth cooling heat exchange unit.

[0008] Furthermore, the fault diagnosis method may also include a first-level judgment step to embed the method and product into an existing system. On the one hand, if there is an interruption request with a higher priority than the diagnosis process, the diagnosis process can be suspended, paused, terminated, and / or ended through the stability judgment process. On the other hand, if the above-mentioned diagnosis process has been completed, the permission flag of the diagnosis process is turned off to prohibit or prevent the re-execution of the diagnosis process within a preset time to save resources and improve system diagnosis efficiency.

[0009] Among them, the stability enhancement judgment process can quantitatively detect the relevant change process by obtaining the over-limit integral K1, which is the cumulative amount of the difference between the actual power output of the drive unit and the ninth duty cycle threshold C9.

[0010] Specifically, the over-limit integral K1 can be used to characterize the degree of interference of at least one of the factors, such as fluid medium flow rate, engine water temperature, speed, load and / or ambient temperature, on its diagnostic process; if the over-limit integral K1 is less than the over-limit threshold C1, the third active intervention step is resumed; otherwise, the diagnostic process can be terminated and the diagnosis can be prohibited from being performed again in the current driving cycle.

[0011] In addition, the fault diagnosis method may also include a fifth threshold calibration step; this fifth threshold calibration step can refine the diagnosis process by obtaining the heating calibration value K2.

[0012] Specifically, the heating calibration value K2 can be used to characterize the heat to be heated in the eighth cooling heat exchange unit or the auxiliary heating unit, or to characterize the integral of the difference between the duty cycle of the execution unit and the ninth duty cycle threshold C9, or to characterize the heating time T1 and / or the heating power of the auxiliary heating unit.

[0013] When the seventh heating heat exchange unit and / or auxiliary heating unit supplement heat, if the heating calibration value K2 is greater than the heating threshold C2 and / or the heating time T1 is greater than the time threshold C3, the diagnostic process can be terminated, and the output power of the drive unit will not be constrained by its ninth duty cycle threshold C9; otherwise, the diagnostic process can continue.

[0014] Specifically, if the diagnostic process is not completed, the third active intervention step can be performed; if the diagnostic process has been completed, the diagnostic process can be terminated and / or the necessary parameter configuration can be restored; the parameter configuration includes limiting the output power of the drive unit; the diagnostic process can perform leak diagnosis on the thermostat; the leak diagnosis method can be the dual water temperature method; the ninth duty cycle threshold C9 is used to characterize the limiting value of the pump speed, speed demand and / or drive capability.

[0015] Accordingly, this invention also discloses a thermal management device, the core of which includes a third active intervention unit; the third active intervention unit can respond to duty cycle limit requests and execute preset diagnostic procedures.

[0016] When responding to a duty cycle limitation request, the output power of the relevant drive unit is limited to a range less than or equal to the ninth duty cycle threshold C9; the drive unit is used to provide power for the heat exchange medium to circulate in a preset heat exchange channel.

[0017] Specifically, the heat exchange channel may further include at least one of a first heating heat exchange unit, a second valve unit, a third cooling heat exchange unit, a fourth medium buffer unit, a sixth cooling heat exchange unit, a seventh heating heat exchange unit, and an eighth cooling heat exchange unit; the heat exchange channel can intervene in the heat exchange process by means of the fluid medium inside the heat exchange channel under the excitation of the driving unit.

[0018] Similarly, its diagnostic process includes diagnosing leakage faults in the second valve unit; this diagnostic process can also employ a dual-temperature diagnostic method; and its first heating heat exchange unit can also obtain heat from the vehicle's engine.

[0019] Specifically, its second valve unit can be the valve unit in the thermostat; its third cooling heat exchange unit can be the radiator of the engine; its fourth medium buffer unit is used to provide space for thermal expansion and contraction, medium replenishment and monitoring of the fluid medium inside the heat exchange channel; its heat exchange channel includes a large circulation passage with a radiator, a small circulation passage short-circuited to the radiator and a third passage including a sixth cooling heat exchange unit, a seventh heating heat exchange unit and / or an eighth cooling heat exchange unit.

[0020] Furthermore, the thermal management device may also be equipped with a first-level judgment unit; if there is an interruption request with a higher priority than its diagnostic process, the device may determine whether the diagnostic process is stopped, suspended, terminated, or ended through stabilization; if the diagnostic process has been completed, the device may disable the permission flag of its diagnostic process to prevent it from being executed again within a preset time.

[0021] The system may also include a stability enhancement judgment process to obtain the over-limit integral K1. The over-limit integral K1 is the cumulative difference between the actual power output of the drive unit and the ninth duty cycle threshold C9. The over-limit integral K1 is used to characterize the degree of interference of at least one of the factors, such as fluid medium flow rate, engine water temperature, speed, load and / or ambient temperature, on the diagnostic process. If the over-limit integral K1 is less than the over-limit threshold C1, the execution of the third active intervention unit is restored; otherwise, the diagnostic process is terminated and the diagnostic process is prohibited from being performed again in the current driving cycle.

[0022] Furthermore, the thermal management device may also be provided with a fifth threshold calibration unit; the fifth threshold calibration unit obtains a heating calibration value K2, which is used to characterize the heat to be heated in the eighth cooling heat exchange unit or the auxiliary heating unit, or to characterize the integral of the difference between the duty cycle of the execution unit and the ninth duty cycle threshold C9, or to characterize the heating time T1 and / or the heating power of the auxiliary heating unit.

[0023] When the seventh heating heat exchange unit and / or auxiliary heating unit supplement heat, if the heating calibration value K2 is greater than the heating threshold C2 and / or the heating time T1 is greater than the time threshold C3, the diagnostic process is terminated, and the output power of the drive unit is not constrained by the ninth duty cycle threshold C9; otherwise, the diagnostic process continues.

[0024] Furthermore, if the diagnostic process is not completed, the execution of the third active intervention unit continues; if the diagnostic process is completed, the diagnostic process is terminated and / or the necessary parameter configuration is restored, including the limitation of the output power of the drive unit; the diagnostic process performs leakage diagnosis on the thermostat; the leakage diagnosis method includes the dual water temperature method; and the ninth duty cycle threshold C9 is used to characterize the limitation value on the pump speed, speed requirement and / or drive capability.

[0025] Similarly, embodiments of the present invention also disclose a computer storage medium, a thermostat, and a controller; wherein the computer storage medium includes a storage medium body for storing a computer program; when the computer program is executed by a microprocessor, it can implement the above-mentioned fault diagnosis method; the thermostat may include any of the above-mentioned thermal management devices and / or the computer storage medium; furthermore, the controller may be a hardware product including the above-mentioned thermal management devices, computer storage medium, and / or thermostat.

[0026] In summary, this invention provides a controllable observation window for fault diagnosis by actively intervening in the thermal management process, which helps to avoid interference from related heat exchange units and ensures the effectiveness and reliability of diagnosis. Based on the existing heat exchange topology and the engine management system (EMS) hardware, it eliminates the risk of misdiagnosis without adding extra components or integrating the diagnostic process.

[0027] Furthermore, by comprehensively considering the initial operating conditions and disturbance factors in the diagnosis and calibrating the threshold, adaptive switching of the diagnosis or detection process is achieved; the coexistence of the existing system and the present invention can also be ensured through the configuration of system priorities, thereby improving the safety and applicability of system modification; and the fault diagnosis capabilities of products such as thermostats and controllers are improved while ensuring the existing functions of the engine system.

[0028] It should be noted that the terms "first," "second," and similar terms used in this article are merely for describing the constituent elements of the technical solution and do not constitute a limitation on the technical solution, nor should they be interpreted as an indication or implication of the importance of the corresponding elements; elements with terms such as "first," "second," or similar terms indicate that at least one of the elements is included in the corresponding technical solution. Attached Figure Description

[0029] To more clearly illustrate the technical solution of the present invention and facilitate a further understanding of its technical effects, features, and objectives, the present invention will be described in detail below with reference to the accompanying drawings. The drawings constitute an essential part of the specification and are used together with Embodiment 1 of the present invention to illustrate the technical solution of the present invention, but do not constitute a limitation on the present invention.

[0030] The same reference numerals in the attached diagrams represent the same parts, specifically: Figure 1 This is a schematic diagram of the engine thermal management system in related technologies.

[0031] Figure 2 This is a schematic diagram of the fault diagnosis process in related technologies.

[0032] Figure 3 This is a schematic diagram of diagnostic data in related technologies.

[0033] Figure 4 This is a schematic diagram of a failure scenario in fault diagnosis in related technologies.

[0034] Figure 5 This is a schematic diagram of the failure diagnosis process data in related technologies.

[0035] Figure 6 This is a schematic flowchart of an embodiment of the diagnostic method of the present invention. Figure 1 .

[0036] Figure 7 This is a schematic flowchart of an embodiment of the diagnostic method of the present invention. Figure 2 .

[0037] Figure 8 This is a schematic diagram of the structural composition of an embodiment of the thermal management device of the present invention.

[0038] Figure 9 This is a schematic diagram of the composition structure of an embodiment of the product of the present invention. Figure 1 .

[0039] Figure 10 This is a schematic diagram of the composition structure of an embodiment of the product of the present invention. Figure 2 .

[0040] Figure 11 This is a schematic diagram of the composition structure of an embodiment of the product of the present invention. Figure 3 .

[0041] Figure 12 This is a schematic diagram of the composition structure of an embodiment of the product of the present invention. Figure 4 .

[0042] in: 010 - First heating heat exchange unit; 011 - Engine water pump operation indicator; 020 - Second valve unit; 022 - Electronic thermostat open indicator; 023 - Large circulation pathway; 025 - Small circulation pathway; 030 - Third cooling heat exchange unit; 031-Fan; 039 - Diagnostic temperature sensor; 040 - Fourth Media Buffer Unit; 050 - Circulation drive unit (water pump); 055 - Electronic water pump duty cycle; 060 - Oil cooler; 070 - Electric heater; 080 - Warm air heat exchanger; 088 - Diagnostic criteria met (marker); 089 - Engine coolant temperature sensor; 100 - First-level judgment steps; 110 - First precondition judgment; 120 - Second Priority Request; 300 - The third active intervention step; 310 - Target Diagnostic Process; 320 - Threshold calibration process two; 330 - Threshold calibration process three; 333 - Diagnostic Procedure; 340-threshold 1 decision; 500 - Fifth threshold calibration step; 510 - Interrupt Handling 1; 520 - Threshold 2 and Threshold 3 decision; 530 - Process Suspended; 599 - Terminate the discrimination step; 600 - Thermal Management Device; 610 - First-level decision unit; 630 - Third Active Intervention Unit; 650 - Fifth threshold calibration unit; 666 - Example Diagnostic Process; 900 - Vehicles; 901 - Controller; 903 - Computer storage media; 906 - Thermostat. Implementation

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described below are merely illustrative of the technical solutions of the present invention, and not intended to limit the invention. Furthermore, the parts described in the embodiments or drawings are merely illustrative examples of relevant parts of the present invention, and not the entirety of the invention.

[0044] like Figure 6 The fault diagnosis method shown includes a third active intervention step 300 for diagnosing faults in the vehicle engine thermal management system; such as Figure 7 As shown, its third active intervention step 300 responds to the duty cycle limit request 310 and executes as follows: Figure 2 The diagnostic procedure shown is 333.

[0045] Among them, such as Figure 1 , Figure 2 As shown, when responding to the duty cycle limiting request 310, the output power of the drive unit 050 is limited to a range less than or equal to the ninth duty cycle threshold C9; the drive unit 050 is used to provide power for the heat exchange medium to circulate in the preset heat exchange channel 001; the heat exchange channel 001 also includes a first heating heat exchange unit 010, a second valve unit 020, a third cooling heat exchange unit 030, a fourth medium buffer unit 040, a sixth cooling heat exchange unit 060, a seventh heating heat exchange unit 070, and an eighth cooling heat exchange unit 080; its heat exchange channel 001, under the excitation of the drive unit 050, intervenes in the heat exchange process with the help of the fluid medium inside the heat exchange channel 001.

[0046] Specifically, such as Figure 1 , Figure 2 The diagnostic process 333 shown includes the diagnosis of leakage faults in the second valve unit 020; the diagnostic process 333 employs a dual water temperature diagnostic method; its first heating heat exchange unit 010 obtains heat from the engine of the vehicle 900.

[0047] Among them, such as Figure 1 , Figure 4 , Figure 12 As shown, the second valve unit 020 includes the valve unit in the thermostat 906; the third cooling heat exchange unit 030 is the engine radiator; its fourth medium buffer unit 040 is the expansion tank, which provides space for thermal expansion and contraction, medium replenishment and monitoring of the fluid medium inside the heat exchange channel 001; its heat exchange channel 001 includes a large circulation passage 023 with a radiator, a small circulation passage 025 short-circuited to the radiator and a third passage 058 including a sixth cooling heat exchange unit 060, a seventh heating heat exchange unit 070 and an eighth cooling heat exchange unit 080.

[0048] Specifically, such as Figure 2 , Figure 6 As shown, the fault diagnosis method also includes a first-level judgment step 100; if there is an interruption request with a higher priority than the diagnosis process 333, the diagnosis process 333 is suspended, paused, terminated and / or ended through the stability judgment process 110; if the diagnosis process 333 has been completed, the permission flag of the diagnosis process 333 is turned off to prohibit or prohibit the re-execution of the diagnosis process 333 within a preset time.

[0049] The stability enhancement judgment process 330 obtains the over-limit integral K1, which is the cumulative difference between the actual power output of the drive unit 050 and the ninth duty cycle threshold C9. The over-limit integral K1 is used to characterize the degree of interference of at least one of the factors of fluid medium flow rate, engine water temperature, speed, load and / or ambient temperature on the diagnostic process 333. If the over-limit integral K1 is less than the over-limit threshold C1, the third active intervention step 300 is resumed; otherwise, the diagnostic process 333 is terminated and the diagnosis is prohibited from being performed again in the current driving cycle 130.

[0050] Furthermore, such as Figure 6 The fault diagnosis method shown also includes a fifth threshold calibration step 500; the fifth threshold calibration step 500 obtains a heating calibration value K2, which is used to characterize the heat to be heated in the eighth cooling heat exchange unit 080 or the auxiliary heating unit, or can characterize the integral of the difference between the duty cycle of the execution unit and the ninth duty cycle threshold C9, or can characterize the heating time T1 and / or the heating power of the auxiliary heating unit.

[0051] When the seventh heating heat exchange unit 070 and / or the auxiliary heating unit supplement heat, if the heating calibration value K2 is greater than the heating threshold C2 and / or the heating time T1 is greater than the time threshold C3, the diagnostic process is terminated, and the output power of its drive unit 050 is no longer constrained by the ninth duty cycle threshold C9; otherwise, the process can continue. Figure 2 The diagnostic procedure shown is 333.

[0052] Specifically, if the diagnostic process 333 is not completed, the third active intervention step 300 can continue to be executed; if the diagnostic process 333 is completed, the diagnostic process can be terminated and / or the necessary parameter configuration can be restored; the parameter configuration includes limiting the output power of the drive unit 050.

[0053] Among them, diagnostic process 333 performs leak diagnosis on the thermostat; the leak diagnosis method is the dual water temperature method; its ninth duty cycle threshold C9 is used to characterize the limitation value on water pump speed, speed requirement and / or drive capability.

[0054] In addition, such as Figure 8 The diagram also discloses a thermal management device 600, including a third active intervention unit 630; the third active intervention unit 630 responds to a duty cycle limit request 310 and executes a preset diagnostic process 333.

[0055] When responding to the duty cycle limitation request 310, the output power of the drive unit 050 is limited to a range less than or equal to the ninth duty cycle threshold C9; the drive unit 050 is used to provide power for the heat exchange medium to circulate in the preset heat exchange channel 001; the heat exchange channel 001 also includes a first heating heat exchange unit 010, a second valve unit 020, a third cooling heat exchange unit 030, a fourth medium buffer unit 040, a sixth cooling heat exchange unit 060, a seventh heating heat exchange unit 070, and an eighth cooling heat exchange unit 080; the heat exchange channel 001, under the excitation of the drive unit 050, intervenes in the heat exchange process with the help of the fluid medium inside the heat exchange channel 001.

[0056] Specifically, its diagnostic process 333 includes the diagnosis of leakage faults in the second valve unit 020; its diagnostic process 333 includes a process using a dual water temperature diagnostic method; and its first heating heat exchange unit 010 obtains heat from the vehicle 900 engine.

[0057] Among them, such as Figure 2 , Figure 4 The second valve unit 020 shown includes, as follows: Figure 12 The valve unit in the thermostat 906 shown; its third cooling heat exchange unit 030 includes the engine radiator; its fourth medium buffer unit 040 provides space for thermal expansion and contraction, medium replenishment and monitoring of the fluid medium inside the heat exchange channel 001; its heat exchange channel 001 includes a large circulation passage 023 with a radiator, a small circulation passage 025 short-circuited to the radiator and a third passage 058 including a sixth cooling heat exchange unit 060, a seventh heating heat exchange unit 070 and / or an eighth cooling heat exchange unit 080.

[0058] Furthermore, such as Figure 2 , Figure 8As shown, the thermal management device 600 may also be provided with a first-level determination unit 610; if there is an interruption request with a priority higher than the diagnostic process 333, the diagnostic process 333 is suspended, paused, terminated and / or ended by the stability determination process 110; if the diagnostic process 333 has been completed, the permission flag of the diagnostic process 333 is turned off to prohibit or prohibit the re-execution of the diagnostic process 333 within a preset time.

[0059] Specifically, the over-limit integral K1 can be obtained through the stability enhancement judgment process 330. The over-limit integral K1 is the cumulative amount of the difference between the actual power output of the drive unit 050 and the ninth duty cycle threshold C9. The over-limit integral K1 is used to characterize the degree of interference of at least one of the factors of fluid medium flow rate, engine water temperature, speed, load and / or ambient temperature on the diagnostic process 333. If the over-limit integral K1 is less than the over-limit threshold C1, the execution of its third active intervention unit 630 is restored; otherwise, the diagnostic process 333 is terminated and the diagnosis is prohibited from being performed again in the current driving cycle 130.

[0060] Furthermore, its thermal management device 600 may also be provided with a fifth threshold calibration unit 650; the fifth threshold calibration unit 650 obtains a heating calibration value K2, and the heating calibration value K2 is used to characterize the heat to be heated in the eighth cooling heat exchange unit 080 or the auxiliary heating unit, or to characterize the integral of the difference between the duty cycle of the execution unit and the ninth duty cycle threshold C9, or to characterize the heating time T1 and / or the heating power of the auxiliary heating unit.

[0061] When the seventh heating heat exchange unit 070 and / or the auxiliary heating unit supplement heat, if the heating calibration value K2 is greater than the heating threshold C2 and / or the heating time T1 is greater than the time threshold C3, the diagnostic process is terminated, and the output power of the drive unit 050 is not constrained by the ninth duty cycle threshold C9; otherwise, the diagnostic process 333 continues to be executed.

[0062] Furthermore, if the diagnostic process 333 is not completed, the execution of the third active intervention unit 630 continues; if the diagnostic process 333 is completed, the diagnostic process is terminated and / or the necessary parameter configuration is restored, including the limitation of the output power of the drive unit 050; wherein, the diagnostic process 333 performs a leak diagnosis on the thermostat; the leak diagnosis method is the dual water temperature method; wherein, the ninth duty cycle threshold C9 is used to characterize the limitation value on the pump speed, speed requirement and / or drive capability.

[0063] Furthermore, such as Figures 9 to 12As shown, a computer storage medium 903, a thermostat 906, and a controller 901 are also disclosed; the computer storage medium 903 includes a storage medium body for storing a computer program; when the computer program is executed by a microprocessor, it can implement the above-mentioned fault diagnosis method; the thermostat 906 includes the above-mentioned thermal management device 600 and / or any of the computer storage medium 903; the controller 901 includes any of the above-mentioned thermal management device 600, computer storage medium 903, and / or thermostat 906.

[0064] In practical applications, such as Figure 1 , Figure 4 The diagram shows a typical thermal management system scheme for the engine, i.e., the first heating heat exchange unit 010. When the engine is running, the high-temperature coolant flows out from the engine outlet, passes through the engine coolant temperature sensor 089, and then flows into the electronic thermostat A, i.e., the inlet A1 of the second valve unit 020. Then, it enters the engine small circulation water circuit, i.e., the small circulation passage 025, and the large circulation water circuit, i.e., the large circulation passage 023, through the outlet A2 and outlet A3, respectively.

[0065] Among them, the electronic thermostat A controls the ratio of coolant entering the small circulation and the large circulation based on thermal management needs. The water entering the small circulation flows directly into the engine electronic water pump, and the water entering the large circulation enters the radiator, i.e., the third cooling heat exchange unit 30, and after being cooled, flows through the diagnostic water temperature sensor 039 at the radiator outlet; then, it flows into the engine electronic water pump, i.e., the drive unit 050.

[0066] Specifically, the coolant from the large and small circulations merges before the engine's electronic water pump, and after being pressurized by the electronic water pump, it is divided into two paths. One path flows into the engine inlet and enters the engine's internal cooling water jacket, while the other path flows into the oil cooler 060, passes through the electric heater 070 and the cabin heater heat exchanger 080, and then flows to the engine outlet. The two coolant paths merge at the engine outlet and then flow to the engine coolant temperature sensor 089.

[0067] The electronic thermostat is a core component of the engine's thermal management system. Its proper functioning directly affects the engine's cooling efficiency, fuel economy, and emissions. If the thermostat is stuck in the fully open position, the engine will continuously circulate heat after a cold start, resulting in a slow temperature rise, worsened fuel consumption and emissions, and accelerated engine wear.

[0068] Therefore, the following can be adopted: Figure 8 The thermal management device shown is used to diagnose a fault where the electronic thermostat is stuck in the maximum open position.

[0069] To address the evolving diagnostic requirements of electronic thermostats and the increasingly complex engine cooling systems, the Engine Management System (EMS) can typically employ methods such as... Figure 2 The "dual water temperature method" shown is used to monitor whether the thermostat is stuck in the fully open position.

[0070] Specifically, the "dual water temperature method" uses a diagnostic temperature sensor 039 added to the radiator outlet and compares the trend deviation between the main water temperature and the diagnostic temperature sensor signal to identify whether the electronic thermostat is stuck in the fully open position, i.e., a leakage fault.

[0071] Its diagnostic strategy, i.e., the diagnostic process, is as follows: Figure 2 As shown.

[0072] If the EMS determines that the thermostat is closed in the main circulation and the diagnostic conditions are met, and the temperature rise of the diagnostic temperature sensor is greater than the threshold, and the temperature rise of the engine outlet coolant temperature sensor is also greater than the threshold, then the thermostat is determined to be stuck in the fully open position, confirming a thermostat leakage fault; otherwise, the EMS determines that the thermostat is normal.

[0073] Specifically, after a cold start to the engine, the EMS instructs the thermostat to close the large circulation loop and open the small circulation loop. At this time, the engine coolant temperature sensor 089 measures the hot coolant temperature as the engine warms up gradually, while the diagnostic temperature sensor 039 measures the cold coolant temperature near the radiator outlet. Their temperature signal changes are as follows: Figure 3 As shown.

[0074] If the thermostat is functioning normally, after a period of time, the engine coolant temperature sensor 089 will show a significant temperature rise △T1, while the temperature rise △T3 of the diagnostic temperature sensor 039 will not be significant. If the thermostat has a leakage fault (stuck in the fully open position), the higher temperature engine coolant will flow to the radiator outlet, and the diagnostic temperature sensor at the radiator outlet will show a significant temperature rise △T2.

[0075] Therefore, it can be seen that when the thermostat is normal, the smaller the temperature rise ΔT3 of the diagnostic temperature sensor is, and the larger the temperature rise ΔT2 of the diagnostic temperature sensor is when the thermostat is leaking. It is easier to distinguish whether the thermostat has a leakage fault (stuck in the fully open position) by the difference between the two temperature rises.

[0076] Typically, placing the diagnostic water temperature sensor at the radiator outlet (on the water pipe adjacent to the radiator outlet) increases the distance between the sensor and the thermostat, reducing the conduction of coolant temperature in the small circulation loop and decreasing ΔT3. However, a diagnostic water temperature sensor at the radiator outlet is closer to the electric water pump inlet. When the electric water pump operates at a high speed, a larger flow of coolant flows through the junction of the large and small circulation loops and into the electric water pump inlet. The high-temperature coolant at the junction will transfer heat to the diagnostic water temperature sensor at the radiator outlet through thermal conduction. Even if the thermostat normally closes the large circulation loop, this thermal conduction problem will increase the temperature rise ΔT3 of the diagnostic water temperature sensor, leading to the following thermal conduction issues: Figure 4 .

[0077] Specifically, its operating scenarios are as follows: After a cold start and at idle, the electric water pump (drive unit) typically maintains a low speed (approximately 10% duty cycle; the electric water pump duty cycle refers to the electrical duty cycle of the motor driving the electric water pump; a higher duty cycle results in a higher pump speed). When the driver turns the heater knob to its maximum, to meet the heating demand (the heat source for the air conditioning mainly comes from the engine coolant; generally, the greater the heat exchange demand, the higher the corresponding electric water pump speed and duty cycle), the electric water pump is pulled up to a higher level (e.g., 70% duty cycle). At this time, the thermostat is normally closed, but the large flow of high-temperature coolant at the electric water pump inlet causes a temperature rise ΔT4 on the diagnostic water temperature sensor due to heat conduction. If this heat conduction continues for a period of time, and the diagnostic prerequisites are met, and the temperature rise ΔT4 on the diagnostic temperature sensor exceeds the threshold when the thermostat is functioning normally, the EMS will falsely report a thermostat malfunction. Figure 5 The leakage fault is shown.

[0078] Among them, when the engine is cold-started and idling, the greater the demand for warm air, the higher the speed of the electronic water pump, the closer the diagnostic water temperature sensor is to the electronic water pump, and the more obvious the temperature of the diagnostic water temperature sensor caused by heat conduction, the greater the diagnostic water temperature rise △T4 when the thermostat is normal, and the more likely the EMS is to falsely report a thermostat leakage fault.

[0079] Compared to the solution of this invention: Related technology 1 avoids misdiagnosis by changing the diagnostic water temperature sensor from the radiator outlet to the radiator inlet; although it can effectively avoid the temperature rise of the diagnostic water temperature sensor caused by the heat conduction of the coolant at the inlet of the electronic water pump, it may aggravate the temperature rise of the diagnostic water temperature sensor caused by the heat conduction of the coolant at the thermostat, and the influence of heat radiation from the motor in the driver's cabin of the hybrid vehicle also needs to be considered; in addition, this method involves changes to the overall vehicle structure design, which is costly and time-consuming.

[0080] Related technology 2 achieves this by modifying the heating thermal management scheme. A common approach is to reduce the duty cycle of the electronic water pump corresponding to the heating demand at engine idle speed, keeping the water pump duty cycle at a low level to reduce the coolant flow at the electronic water pump inlet and avoid excessive temperature rise of the diagnostic water temperature sensor caused by heat conduction of the coolant at the electronic water pump inlet. Specifically, at low ambient temperatures, this method will result in the electronic water pump duty cycle corresponding to the heating demand being limited, leading to insufficient heating in the passenger compartment and affecting passenger comfort. At the same time, due to the lack of reasonable control interaction between thermostat diagnosis and thermal management control, the problem often occurs where the electronic water pump corresponding to the heating demand is still limited even after the thermostat diagnosis ends.

[0081] like Figure 1 As shown, this embodiment is based on existing components of the typical thermal management system of the engine in the hybrid vehicle 900, and upgrades the function by improving the control scheme.

[0082] First, the engine control system (EMS) confirms that the prerequisites for thermostat leak diagnosis are met and the diagnosis is not yet complete. Then, it sends an electronic water pump duty cycle diagnosis limit request (corresponding to the thermostat diagnosis duty cycle limit) to the thermal management system. After receiving the request, the thermal management system first determines whether there is a higher priority electronic water pump request, and then determines whether to respond.

[0083] Specifically, if there is no higher-priority electric water pump request, the thermal management system instructs the electric water pump duty cycle not to exceed the diagnostic duty cycle limit, and the EMS initiates thermostat leak diagnosis; the thermostat leak diagnosis strategy is as follows: Figure 2 As shown, this solution employs a dual-water-temperature thermostat leakage diagnosis strategy.

[0084] Simultaneously, EMS integrates the difference between the demand duty cycle and the diagnostic duty cycle limit of the electric water pump for heating. The integral result can be interpreted as the degree to which heating demand is not met due to the water pump duty cycle being limited; at the same time, it can trigger events such as... Figure 1 The electric heater shown is a positive temperature coefficient thermistor (PTC). The electric heating power, converted from the integral result, supplements the coolant in the heating air branch. This electric heating power is equal to the integral result multiplied by the electric water pump coolant flow correction and heat transfer characteristic correction. Furthermore, if the integral result is greater than a threshold and the duration exceeds the threshold, it is considered that the supplementary heating by the electric heater is still insufficient to meet the cabin heating demand. In this case, the EMS (Electronic Stability Management) withdraws its duty cycle limiting intervention on the electric water pump, and the electric water pump responds to the heating air duty cycle. Conversely, if the integral result is less than the threshold, the electric water pump responds to the thermostat's diagnostic duty cycle limiting intervention.

[0085] Meanwhile, if a higher priority request is received, the thermal management system will not respond to the electronic water pump duty cycle diagnostic limit request, but will respond to the higher priority request. The EMS integrates the difference between the actual electronic water pump duty cycle and the diagnostic duty cycle limit. The integration result can be understood as the degree to which the heat conduction of the electronic water pump inlet coolant affects the diagnostic water temperature rise due to the actual water pump duty cycle exceeding the diagnostic duty cycle limit. If the integration result is greater than the threshold, it can be considered that the electronic water pump operating duty cycle has been too high for a long time, and the heat conduction of the electronic water pump inlet coolant has too great an impact on the diagnostic water temperature rise. The diagnostic water temperature rise is severely interfered with and is not suitable for judging whether the thermostat is leaking. At this time, the thermostat leak diagnosis is interrupted, and the diagnosis will no longer be performed in this driving cycle 130.

[0086] Among them, the duty cycle limit of thermostat diagnosis can be calibrated based on ambient temperature. The lower the ambient temperature, the more urgent the heating demand of the passenger compartment. The influence of heat conduction of small circulation coolant on the diagnostic water temperature sensor is reduced due to low temperature heat dissipation. Therefore, as the ambient temperature decreases, the duty cycle limit of thermostat diagnosis on water pump increases.

[0087] Specifically, higher priority water pump requests typically occur when the engine coolant temperature exceeds the limit, the diagnostic tool triggers a water pump test, or there is a malfunction in thermal management-related actuators or sensors (fan, water temperature, etc.).

[0088] Furthermore, during the period when the thermal management system instructs the electronic water pump to respond to the diagnostic duty cycle limit, if a higher priority water pump request occurs, the electronic water pump will exit the thermostat diagnostic duty cycle limit intervention and respond to the higher priority water pump request duty cycle.

[0089] Meanwhile, the EMS integrates the difference between the actual electronic water pump duty cycle and the diagnostic duty cycle limit. If the integration result is greater than the threshold, it can be considered that the electronic water pump's operating duty cycle has been too high for a long time, and the heat conduction of the electronic water pump inlet coolant has too great an impact on the diagnostic water temperature rise. The diagnostic water temperature rise is severely interfered with and is not suitable for judging whether the thermostat is leaking. Accordingly, the thermostat leak diagnosis will not be performed in this driving cycle 130. Correspondingly, if the integration result is less than the threshold, once the higher priority water pump duty cycle request is withdrawn, the electronic water pump will respond to the diagnostic duty cycle limit again.

[0090] Specifically, such as Figure 7The over-limit integral K1 is the integral result of the difference between the actual electronic water pump duty cycle and the diagnostic duty cycle limit. The over-limit threshold C1 is the corresponding judgment threshold. This threshold needs to take into account the heat transfer characteristics such as coolant flow rate and ambient temperature. Based on the data calibration of the C1 threshold, when K1 is greater than C1, the EMS determines that the coolant at the inlet of the corresponding electronic water pump has too great an impact on the heat conduction of the diagnostic water temperature sensor, which is prone to false alarms, and then interrupts the thermostat leak diagnosis. When K1 is less than C1, the EMS will issue an electronic water pump duty cycle diagnostic limit request and continue the thermostat leak diagnosis.

[0091] Furthermore, as above Figure 7 As shown, the heating calibration value K2 is the integral result of the difference between the demand duty cycle of the electric water pump and the diagnostic duty cycle limit. The heating threshold C2 is the corresponding judgment threshold. This threshold needs to be corrected for heat transfer characteristics such as coolant flow rate and ambient temperature. Based on the data calibration of the C2 threshold, when K2 is greater than C2, the EMS determines that the heating demand is insufficient due to the water pump duty cycle being limited, resulting in insufficient heating in the passenger compartment. At the same time, the duration T1 of the electric heater's supplementary heating is timed. When T1 is greater than the time length threshold C3, the vehicle thermal management system believes that even if the electric heater provides supplementary heating for a certain period of time, the passenger compartment is still insufficiently heated and significantly affects passenger comfort. At this time, the EMS withdraws its intervention on the duty cycle diagnostic limitation of the electric water pump.

[0092] As mentioned above, the embodiments provide a scheme for the cooperation between the engine control system (EMS) and the vehicle thermal management control system; wherein, the engine thermostat leakage diagnosis can actively intervene in the thermal management control and exit in a timely manner; it solves the common problem of temperature rise interference caused by the heat conduction of the electronic water pump inlet coolant to the diagnostic water temperature sensor, i.e., the inability to perform thermostat diagnosis; its technical effects include: On the one hand, it can be implemented based on existing hybrid vehicle engine components without adding components, changing the vehicle engine sensor layout, or altering the relevant structural design.

[0093] On the other hand, it can also take into account the cooling needs of higher priority electronic water pumps. If the system recognizes a higher priority electronic water pump duty cycle command, the electronic water pump can exit the thermostat diagnostic duty cycle limit intervention, ensuring the safety of vehicle thermal management.

[0094] Furthermore, when the electric water pump does not respond to the diagnostic duty cycle limit, the EMS integrates the difference between the actual electric water pump duty cycle and the diagnostic duty cycle limit. This integration result corresponds to the entire heat transfer physical process and can effectively characterize the degree of influence of the electric water pump inlet coolant on the thermal conduction of the diagnostic water temperature sensor due to the excessively high actual operating duty cycle of the electric water pump. Specifically, if it is identified that the influence of the electric water pump inlet coolant on the thermal conduction of the diagnostic water temperature sensor is too large, that is, when false alarms are likely to occur, the thermostat leakage diagnosis is interrupted.

[0095] When the electronic water pump responds to the diagnostic duty cycle limit, the EMS integrates the difference between the required duty cycle of the heating electronic water pump and the diagnostic duty cycle limit. This integration result can not only be converted into electric heating power to supplement the heating coolant in the heating branch, but also, combined with time detection, identify insufficient heating in the passenger cabin. This allows the electronic water pump to promptly release the diagnostic duty cycle limit and respond to the heating duty cycle demand, avoiding the problem of insufficient heating for a long time due to the water pump being interfered with during the diagnostic process, which affects passenger comfort.

[0096] Specifically, the parameter K1 mentioned above is the integral result of the difference between the actual electronic water pump duty cycle and the diagnostic duty cycle limit. It can be corrected based on signals such as coolant flow rate, ambient temperature, engine water temperature, speed, and load. Through calibration, a reasonably accurate thermal conduction process of the electronic water pump inlet coolant to the diagnostic water temperature sensor can be obtained.

[0097] Secondly, parameter K2 is the integral result of the difference between the required duty cycle and the diagnostic duty cycle limit of the electric heater water pump. It can be corrected based on signals such as coolant flow rate, ambient temperature, engine water temperature, passenger compartment temperature, and electric heater power characteristics. Through calibration, the electric heater supplementary power requirement can be obtained to meet reasonable accuracy.

[0098] Furthermore, the duty cycle of the electronic water pump refers to the electrical duty cycle that drives the electric water pump motor to rotate. The larger the duty cycle, the higher the speed of the electronic water pump. Therefore, the "electronic water pump duty cycle" can be equivalently replaced by "electronic water pump speed" and "electronic water pump duty cycle requirement", etc., which can be equivalently replaced by "electronic water pump speed requirement".

[0099] It should be noted that the above embodiments are only for more clearly illustrating the technical solution of the present invention. Those skilled in the art will understand that the implementation of the present invention is not limited to the above content. Any obvious changes, substitutions or replacements made based on the above content do not exceed the scope of the technical solution of the present invention. Other implementations will also fall within the scope of the present invention without departing from the concept of the present invention.

Claims

1. A fault diagnosis method, characterized in that... The system includes a third active intervention step (300); the third active intervention step (300) responds to a duty cycle limitation request (310) from the drive unit (050) and executes a preset diagnostic process (333); wherein, when responding to the duty cycle limitation request (310), the output power of the drive unit (050) is limited to a range less than or equal to a ninth duty cycle threshold C9; the drive unit (050) is used to provide power for the heat exchange medium to circulate in a preset heat exchange channel (001); the heat exchange channel (001) further includes at least one of a first heating heat exchange unit (010), a second valve unit (020), a third cooling heat exchange unit (030), a fourth medium buffer unit (040), a sixth cooling heat exchange unit (060), a seventh heating heat exchange unit (070), and an eighth cooling heat exchange unit (080); the heat exchange channel (001) intervenes in the heat exchange process by means of the fluid medium inside the heat exchange channel (001) under the excitation of the drive unit (050); The diagnostic process (333) includes the diagnosis of leakage faults in the second valve unit (020); the diagnostic process (333) includes a process using a dual water temperature diagnostic method; wherein, the dual water temperature diagnostic method includes: after determining that the thermostat closes the large circulation and the diagnostic conditions are met, if the temperature rise of the radiator outlet diagnostic temperature sensor is greater than the threshold, and the temperature rise of the engine outlet coolant temperature sensor is greater than the threshold, then it is determined that the thermostat is stuck in the fully open position, and it is confirmed that the thermostat is leaking; otherwise, it is determined that the thermostat is normal. The drive unit (050) includes an electronic water pump, the first heating heat exchange unit (010) includes an engine, the second valve unit (020) includes a valve unit in an electronic thermostat, the third cooling heat exchange unit (030) includes a radiator, the fourth medium buffer unit (040) includes an expansion tank, the sixth cooling heat exchange unit (060) includes an oil cooler, the seventh heating heat exchange unit (070) includes an electric heater, and the eighth cooling heat exchange unit (080) includes a hot air exchanger for the cabin.

2. The fault diagnosis method as described in claim 1, wherein: The first heating heat exchange unit (010) obtains heat from the vehicle (900) engine.

3. The fault diagnosis method of claim 2, wherein: The fourth medium buffer unit (040) provides space for thermal expansion and contraction, medium replenishment and monitoring of the fluid medium inside the heat exchange channel (001); the heat exchange channel (001) includes a large circulation path (023) with the radiator, a small circulation path (025) short-circuited to the radiator and a third path (058) including the sixth cooling heat exchange unit (060), the seventh heating heat exchange unit (070) and / or the eighth cooling heat exchange unit (080).

4. The fault diagnosis method according to any one of claims 1 to 3 further includes a first-level determination step (100); if there is an interruption request with a higher priority than the diagnosis process (333), the diagnosis process (333) is suspended, paused, terminated and / or ended through the stability discrimination process (110); if the diagnosis process (333) has been completed, the permission flag of the diagnosis process (333) is turned off to prohibit or prohibit the re-execution of the diagnosis process (333) within a preset time.

5. The fault diagnosis method as described in claim 4, wherein: The stability enhancement discrimination process (330) obtains the over-limit integral K1, which is the cumulative difference between the actual power output of the drive unit (050) and the ninth duty cycle threshold C9. The over-limit integral K1 is used to characterize the degree of interference of at least one of the fluid medium flow rate, engine water temperature, speed, load and / or ambient temperature on the diagnostic process (333). If the over-limit integral K1 is less than the over-limit threshold C1, the third active intervention step (300) is resumed; otherwise, the diagnostic process (333) is terminated and the diagnosis is prohibited from being performed again in the current driving cycle (130).

6. The fault diagnosis method according to any one of claims 1 to 3 further includes a fifth threshold calibration step (500); the fifth threshold calibration step (500) obtains a heating calibration value K2, the heating calibration value K2 being used to characterize the heat to be heated in the eighth cooling heat exchange unit (080) or the auxiliary heating unit, or to characterize the integral of the difference between the duty cycle of the driving unit and the ninth duty cycle threshold C9, or to characterize the heating time T1 and / or the heating power of the auxiliary heating unit.

7. The fault diagnosis method as described in claim 6, wherein: When the seventh heating heat exchange unit (070) and / or the auxiliary heating unit supplement heat, if the heating calibration value K2 is greater than the heating threshold C2 and / or the heating time T1 is greater than the time threshold C3, the diagnostic process is terminated, and the output power of the drive unit (050) is not constrained by the ninth duty cycle threshold C9; otherwise, the diagnostic process (333) continues to be executed.

8. The fault diagnosis method as described in claim 7, wherein: If the diagnostic process (333) is not completed, the third active intervention step (300) continues; if the diagnostic process (333) is completed, the diagnostic process is terminated and / or the necessary parameter configuration is restored, the parameter configuration including the limitation of the output power of the drive unit (050); the diagnostic process (333) performs a leak diagnosis on the thermostat; the leak diagnosis method includes a dual water temperature diagnosis method; The ninth duty cycle threshold C9 is used to characterize the limits on pump speed, speed demand, and / or drive capability.

9. A thermal management device (600) includes a third active intervention unit (630); the third active intervention unit (630) responds to a duty cycle limitation request (310) from a drive unit (050) and executes a preset diagnostic process (333); wherein, When responding to the duty cycle limiting request (310), the output power of the drive unit (050) is limited to a range less than or equal to the ninth duty cycle threshold C9; the drive unit (050) is used to provide power for the heat exchange medium to circulate in the preset heat exchange channel (001); the heat exchange channel (001) further includes at least one of the following: a first heating heat exchange unit (010), a second valve unit (020), a third cooling heat exchange unit (030), a fourth medium buffer unit (040), a sixth cooling heat exchange unit (060), a seventh heating heat exchange unit (070), and an eighth cooling heat exchange unit (080); the heat exchange channel (001) intervenes in the heat exchange process by means of the fluid medium inside the heat exchange channel (001) under the excitation of the drive unit (050); The diagnostic process (333) includes diagnosing leakage faults in the second valve unit (020); The diagnostic process (333) includes a process using a dual water temperature diagnostic method; wherein, the dual water temperature diagnostic method includes: after determining that the thermostat closes the large circulation and the diagnostic conditions are met, if the temperature rise of the radiator outlet diagnostic temperature sensor is greater than the threshold and the temperature rise of the engine outlet coolant temperature sensor is greater than the threshold, then it is determined that the thermostat is stuck in the fully open position and confirmed as a thermostat leakage fault; otherwise, it is determined that the thermostat is normal. The drive unit (050) includes an electronic water pump, the first heating heat exchange unit (010) includes an engine, the second valve unit (020) includes a valve unit in an electronic thermostat, the third cooling heat exchange unit (030) includes a radiator, the fourth medium buffer unit (040) includes an expansion tank, the sixth cooling heat exchange unit (060) includes an oil cooler, the seventh heating heat exchange unit (070) includes an electric heater, and the eighth cooling heat exchange unit (080) includes a hot air exchanger for the cabin.

10. The thermal management device (600) as claimed in claim 9, wherein: The first heating heat exchange unit (010) obtains heat from the vehicle (900) engine.

11. The thermal management device (600) of claim 10, wherein: The fourth medium buffer unit (040) provides space for thermal expansion and contraction, medium replenishment and monitoring of the fluid medium inside the heat exchange channel (001); the heat exchange channel (001) includes a large circulation path (023) with the radiator, a small circulation path (025) short-circuited to the radiator and a third path (058) including the sixth cooling heat exchange unit (060), the seventh heating heat exchange unit (070) and / or the eighth cooling heat exchange unit (080).

12. The thermal management device (600) according to any one of claims 9 to 11 further includes a first-level determination unit (610); if there is an interruption request with a higher priority than the diagnostic process (333), the diagnostic process (333) is suspended, paused, terminated and / or ended by the stability determination process (110); if the diagnostic process (333) has been completed, the permission flag of the diagnostic process (333) is turned off to prohibit or prohibit the re-execution of the diagnostic process (333) within a preset time.

13. The thermal management device (600) as claimed in claim 12, wherein: The stability enhancement discrimination process (330) obtains the over-limit integral K1, which is the cumulative difference between the actual power output of the drive unit (050) and the ninth duty cycle threshold C9. The over-limit integral K1 is used to characterize the degree of interference of at least one of the fluid medium flow rate, engine water temperature, speed, load and / or ambient temperature on the diagnostic process (333). If the over-limit integral K1 is less than the over-limit threshold C1, the execution of the third active intervention unit (630) is restored; otherwise, the diagnostic process (333) is terminated and the diagnosis is prohibited from being performed again in the current driving cycle (130).

14. The thermal management device (600) according to any one of claims 9 to 11, further comprising a fifth threshold calibration unit (650); the fifth threshold calibration unit (650) acquires a heating calibration value K2, the heating calibration value K2 being used to characterize the heat to be heated in the eighth cooling heat exchange unit (080) or the auxiliary heating unit, or to characterize the integral of the difference between the duty cycle of the drive unit and the ninth duty cycle threshold C9, or to characterize the heating time T1 and / or the heating power of the auxiliary heating unit.

15. The thermal management device (600) as claimed in claim 14, wherein: When the seventh heating heat exchange unit (070) and / or the auxiliary heating unit supplement heat, if the heating calibration value K2 is greater than the heating threshold C2 and / or the heating time T1 is greater than the time threshold C3, the diagnostic process is terminated, and the output power of the drive unit (050) is not constrained by the ninth duty cycle threshold C9; otherwise, the diagnostic process (333) continues to be executed.

16. The thermal management device (600) as claimed in claim 15, wherein: If the diagnostic process (333) is not completed, the execution of the third active intervention unit (630) continues; if the diagnostic process (333) is completed, the diagnostic process is terminated and / or the necessary parameter configuration is restored, the parameter configuration including the limitation of the output power of the drive unit (050); the diagnostic process (333) performs a leak diagnosis on the thermostat; the leak diagnosis method includes a dual water temperature diagnosis method; The ninth duty cycle threshold C9 is used to characterize the limits on pump speed, speed demand, and / or drive capability.

17. A computer storage medium (903) comprising a storage medium body for storing a computer program; wherein the computer program, when executed by a microprocessor, implements the fault diagnosis method as described in any one of claims 1 to 8.

18. A thermostat (906) comprising the thermal management device (600) of any one of claims 9 to 16 and / or the computer storage medium (903) of claim 17.

19. A controller (901) comprising the thermal management device (600) of any one of claims 9 to 16 and / or the computer storage medium (903) of claim 17 and / or the thermostat (906) of claim 18.

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