Diagnostic control method and system for engine cooling system, controller and automobile

Abstract

The invention discloses a diagnostic control method and system for an engine cooling system, a controller and an automobile. The method comprises the steps that when an engine is in a current mode, actually-measured data are obtained, and the actually-measured data comprise at least one of the actually-measured temperature, the outlet water temperature, the inlet water temperature and the engine oil temperature of the engine; acquiring a target temperature threshold value corresponding to the current mode; acquiring a fault detection result according to the actually measured temperature of the engine and a target temperature threshold value corresponding to the current mode; and when the fault detection result shows that the fault exists, the engine fault level is determined, and a target control strategy corresponding to the engine fault level is executed. According to the method, whether the engine has a fault in the current mode or not can be quickly evaluated according to the actually measured temperature of the engine and the target temperature threshold value corresponding to the current mode, the fault level of the engine is determined, and the corresponding target control strategy is executed, so that the purpose of guaranteeing the accuracy of fault diagnosis and control is achieved, and normal work of the engine is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a diagnosis control method, system, controller and automobile of an engine cooling system. Background Art

[0002] The engine cooling system currently on the market generally includes the following two designs: The first is a cylinder block and cylinder head series design, which is mainly used in conventional and traditional models. Its main feature is that the flow pumped out by the electronic water pump flows through the cylinder block and the cylinder head, that is, the total flow of the electronic water pump is equal to the cylinder block flow and the cylinder head flow. The coolant needs to absorb the heat of the cylinder block and the cylinder head at the same time, the temperature rise is large, and the system pressure loss is large. The second is a cylinder block and cylinder head parallel design (i.e., split flow design), which is mainly characterized by the flow pumped out by the electronic water pump partially entering the cylinder block and partially entering the cylinder head. The electronic water pump flow is the sum of the cylinder block flow and the cylinder head flow. The coolant only absorbs the heat of the cylinder block or the cylinder head, the temperature rise is small, the system pressure loss is small, but the total flow of the electronic water pump is large. In the existing engine cooling system, when the engine is in different operating modes, the relevant components in the engine cooling system (for example, the temperature control module for controlling the cylinder block to be connected to the electronic water pump, the bypass valve for controlling the cylinder head to be connected to the electronic water pump, or the electronic water pump for adjusting the flow) are in different states. At this time, there is a lack of fault diagnosis and control processing when the engine is in different operating modes, and accurate diagnosis and control cannot be achieved, which affects the normal operation of the engine. Summary of the invention

[0003] The embodiments of the present invention provide a diagnosis and control method, system, controller and automobile of an engine cooling system to solve the problem that the prior art cannot accurately diagnose and control faults existing in different working modes of the engine.

[0004] A diagnostic control method for an engine cooling system, comprising:

[0005] When the engine is in the current mode, obtaining measured data, the measured data including the measured temperature of the engine, at least one of the outlet water temperature, the inlet water temperature and the oil temperature;

[0006] Obtaining a target temperature threshold corresponding to the current mode;

[0007] acquiring the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode;

[0008] When the fault detection result indicates that a fault exists, an engine fault level is determined, and a target control strategy corresponding to the engine fault level is executed.

[0009] An engine controller comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above-mentioned engine cooling system diagnosis control method is implemented.

[0010] An engine cooling system comprises a cylinder block, a cylinder head, an electronic water pump, a warm air branch, a temperature control branch, a first temperature sensor, a second temperature sensor, a third temperature sensor and the above engine controller;

[0011] The cylinder body and the cylinder head cooperate to form a cylinder circulation branch;

[0012] The warm air branch is arranged between the first outlet of the cylinder head and the inlet of the electronic water pump, and comprises a bypass valve and a warm air core arranged in series;

[0013] The temperature control branch includes a temperature control module and a radiator, the inlet of the temperature control module is connected to the first outlet of the cylinder body, the outlet of the temperature control module is connected to the inlet of the electronic water pump, or the outlet of the temperature control module is connected to the inlet of the electronic water pump through the radiator;

[0014] The outlet of the electronic water pump is connected to the first inlet of the cylinder body;

[0015] The first temperature sensor is arranged at the first outlet of the cylinder body and is used to collect the outlet water temperature of the engine;

[0016] The second temperature sensor is arranged at the first inlet of the cylinder body and is used to collect the inlet water temperature of the engine;

[0017] The third temperature sensor is arranged on the cylinder body and is used to collect the oil temperature of the engine;

[0018] The engine controller is connected to the first temperature sensor, the second temperature sensor, the third temperature sensor, the temperature control module, the bypass valve, the temperature control module and the electronic water pump, and is used to perform diagnostic control according to the outlet water temperature, the inlet water temperature and the engine oil temperature.

[0019] An automobile comprises the above engine cooling system.

[0020] The diagnostic control method, system, controller and automobile of the above-mentioned engine cooling system first quickly evaluate whether there is a fault in the engine in the current mode based on the comparison result of the actual engine temperature and the target temperature threshold corresponding to the current mode to obtain a fault detection result. When the fault detection result is that a fault exists, the engine fault level is determined and the target control strategy corresponding to the engine fault level is executed to achieve the purpose of ensuring the accuracy of fault diagnosis and control, thereby ensuring the normal operation of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0022] Figure 1 is a schematic diagram of an engine cooling system in one embodiment of the present invention;

[0023] Figure 2 is a flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0024] Figure 3 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0025] Figure 4 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0026] Figure 5 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0027] Figure 6 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0028] Figure 7 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0029] Figure 8 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0030] Fig. 9 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0031] Fig.10 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0032] Fig.11 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0033] Fig.12 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention;

[0034] Fig.13 is another flow chart of a diagnostic control method for an engine cooling system in one embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] An engine cooling system according to an embodiment of the present invention is as follows: Figure 1 As shown, the engine cooling system includes a cylinder block, a cylinder head, an electronic water pump, a warm air branch, a temperature control branch and an engine controller; the cylinder block and the cylinder head cooperate to form a cylinder circulation branch; the warm air branch is arranged between the first outlet of the cylinder head and the inlet of the electronic water pump, and includes a bypass valve and a warm air core arranged in series; the temperature control branch includes a temperature control module and a radiator, the inlet of the temperature control module is connected to the first outlet of the cylinder block, the outlet of the temperature control module is connected to the inlet of the electronic water pump, or the outlet of the temperature control module is connected to the inlet of the electronic water pump through the radiator; the outlet of the electronic water pump is connected to the first inlet of the cylinder block; the engine controller is connected to the temperature control module, the bypass valve and the electronic water pump, and is used to control the operation of the temperature control module, the bypass valve and the electronic water pump.

[0037] As an example, an outlet of the cylinder body is connected to an inlet of the cylinder head through a first pipe, and an outlet of the cylinder head is connected to an inlet of the cylinder body through a second pipe, so that a cylinder circulation branch is formed between the cylinder body and the cylinder head, and the coolant flowing into the cylinder body from the electronic water pump first flows into the cylinder body, flows from the cylinder body into the cylinder head through the first pipe, and flows back to the cylinder body from the cylinder head through the second pipe, so that the coolant flows between the cylinder body and the cylinder head, so that the coolant can absorb the heat of the cylinder body and the cylinder head. In this example, when the bypass valve of the warm air branch is closed and the opening of the temperature control module is zero, the coolant only flows in the cylinder circulation branch formed between the cylinder body and the cylinder head, which can absorb the heat of the cylinder body and the cylinder head at the same time, ensuring the series cooling effect of the cylinder body and the cylinder head.

[0038] As an example, the warm air branch is arranged between the first outlet of the cylinder head and the inlet of the electronic water pump, including a bypass valve and a warm air core arranged in series, and the engine controller is connected to the bypass valve, which can control the bypass valve to work based on the target opening, so that the coolant output from the cylinder head can flow back into the cylinder body through the warm air core-electronic water pump, so that the warm air core can achieve a warm air effect. In this example, the warm air branch is independently controlled by the engine controller, which can avoid the heat flow of the warm air branch affecting the refrigeration pipeline through radiation or convection and affecting the maximum refrigeration effect when high-power cooling of the air conditioner is required.

[0039] As an example, the temperature control branch is arranged between the first outlet of the cylinder body and the inlet of the electronic water pump, specifically including a temperature control module and a radiator, the inlet of the temperature control module is connected to the first outlet of the cylinder body, the first outlet of the temperature control module is directly connected to the inlet of the electronic water pump, and the second outlet of the temperature control module is connected to the inlet of the electronic water pump through the radiator. When the first outlet of the temperature control module is directly connected to the inlet of the electronic water pump, it can be determined that the temperature control branch enters a small circulation state, that is, a circulation state of cylinder body-temperature control module-electronic water pump-cylinder body; when the second outlet of the temperature control module is connected to the inlet of the electronic water pump through the radiator, it can be determined that the temperature control branch enters a large circulation state, that is, a circulation state of cylinder body-temperature control module-radiator-electronic water pump-cylinder body. Among them, the temperature control module is connected to the engine controller, and can control the first outlet of the cylinder body to be directly connected to the inlet of the electronic water pump, or to be indirectly connected to the inlet of the electronic water pump through the radiator according to the control instructions sent by the engine controller, so as to achieve the goal of autonomously determining whether it is necessary to return the coolant in the cylinder body to the electronic water pump according to actual conditions, and when it needs to return to the electronic water pump, whether to return directly or indirectly through the radiator.

[0040] As an example, the temperature control module is adaptively adjusted to the small circulation state or the large circulation state, and the engine controller can control the bypass valve to open or close. There are several corresponding switching modes: the first switching mode is that the temperature control module enters the small circulation state, and the bypass valve is closed; the second switching mode is that the temperature control module enters the small circulation state, and the bypass valve is opened; the third switching mode is that the temperature control module enters the large circulation state, and the bypass valve is closed; the fourth switching mode is that the temperature control module enters the large circulation state, and the bypass valve is opened; the fifth switching mode is that the temperature control module does not work (that is, the target opening of the temperature control branch is zero), and the bypass valve is closed; the sixth mode is that the temperature control module does not work, and the bypass valve is opened. Since when the temperature control module enters the large circulation state, it means that the temperature in the cylinder is relatively high. At this time, the radiator needs to be used to quickly dissipate heat. At this time, the bypass valve is generally not controlled to open to divert the warm air core. Therefore, the fourth switching mode rarely occurs. The second switching method is a transition between the first switching method and the third switching method, that is, the radiator is used as the core cooling element, and the heater core is used as an auxiliary transition cooling element, which can achieve two-speed cooling performance and create a difference in the diversion cooling of the cylinder block and the cylinder head. On the premise of ensuring that the cylinder head does not overheat and the combustion chamber does not detonate, the opening time of the temperature control module is delayed to further increase the temperature of the engine oil and reduce friction.

[0041] In this embodiment, a cylinder circulation branch is formed between the cylinder block and the cylinder head, which can absorb the heat of the cylinder block and the cylinder head at the same time, ensuring the cooling effect of the cylinder block and the cylinder head in series; the warm air branch is arranged between the first outlet of the cylinder head and the inlet of the electronic water pump, and the opening of the bypass valve and the speed of the electronic water pump can be adjusted to ensure the cooling effect of the warm air branch on the cylinder head; the temperature control branch is arranged between the first outlet of the cylinder block and the inlet of the electronic water pump, and the opening of the temperature control module and the speed of the electronic water pump can be adjusted to ensure the cooling effect of the temperature control branch on the cylinder block; moreover, the warm air branch and the temperature control branch are connected in parallel to the inlet of the electronic water pump, and then flow back to the cylinder block through the electronic water pump, so that the coolant in the warm air branch and the temperature control branch does not affect each other, which helps to ensure the cooling effect. Moreover, the engine controller is connected to the temperature control module, the bypass valve and the electronic water pump, so as to realize the refined control of the temperature control module, the bypass valve and the electronic water pump, which helps to ensure the cooling effect of the engine. In this example, the radiator serves as the core cooling element, while the heater core serves as an auxiliary transition cooling element, which can achieve two-speed cooling performance and create a difference in the diversion cooling of the cylinder block and the cylinder head. On the premise of ensuring that the cylinder head does not overheat and the combustion chamber does not detonate, the opening time of the temperature control module is delayed to further increase the temperature of the engine oil and reduce friction.

[0042] In one embodiment, the engine cooling system also includes a first temperature sensor, a second temperature sensor and a third temperature sensor; the first temperature sensor is arranged at the first outlet of the cylinder body, and is used to collect the outlet water temperature of the engine; the second temperature sensor is arranged at the first inlet of the cylinder body, and is used to collect the inlet water temperature of the engine; the third temperature sensor is arranged on the cylinder body, and is used to collect the engine oil temperature; the engine controller is connected to the first temperature sensor, the second temperature sensor and the third temperature sensor, and is used to control the operation of the temperature control module, the bypass valve temperature control module and the electronic water pump according to the outlet water temperature, the inlet water temperature and the engine oil temperature.

[0043] As an example, the first temperature sensor is a temperature sensor arranged on the first outlet of the cylinder body, specifically a temperature sensor arranged between the first outlet of the cylinder body and the inlet of the electronic water pump, for collecting the outlet water temperature T1 of the engine and sending the outlet water temperature T1 to the engine controller.

[0044] As an example, the second temperature sensor is a temperature sensor arranged on the first inlet of the cylinder body, specifically a temperature sensor arranged between the outlet of the electronic water pump and the first inlet of the cylinder body, for collecting the inlet water temperature T2 of the engine and sending the inlet water temperature T2 to the engine controller.

[0045] As an example, the third temperature sensor is a temperature sensor arranged on the cylinder block, specifically a temperature sensor arranged on a portion of the cylinder block for assembling the engine oil, for collecting the engine oil temperature T3 and sending the engine oil temperature T3 to the engine controller.

[0046] As an example, the engine controller is connected to the first temperature sensor, the second temperature sensor, and the third temperature sensor, and can determine the target mode that the engine needs to be controlled to enter based on the outlet water temperature T1 of the engine collected by the first temperature sensor, the inlet water temperature T2 of the engine collected by the second temperature sensor, and the engine oil temperature T3 collected by the third temperature sensor, and then control the temperature control to work based on the first target opening corresponding to the target mode, control the bypass valve to work based on the second target opening corresponding to the target mode, and control the electronic water pump to work based on the target speed of the target mode to meet the cooling requirements corresponding to the target mode. In this example, the engine controller can achieve fine control of the temperature control module, bypass valve, and electronic water pump based on the outlet water temperature T1, the inlet water temperature T2, and the engine oil temperature T3, which helps to ensure the cooling effect of the engine.

[0047] In one embodiment, the engine cooling system further comprises a supercharger, wherein an inlet of the supercharger is connected to the second outlet of the cylinder block, and an outlet of the supercharger is connected to an inlet of the cylinder head.

[0048] As an example, the supercharger is disposed between the second outlet of the cylinder block and the inlet of the cylinder head, and coolant can be drawn from the second outlet of the cylinder block and then returned to the cylinder head without the need for an additional overflow pipe, which helps save costs and simplify the structure.

[0049] In one embodiment, an overflow port is provided on the cylinder head; the engine cooling system further comprises an expansion water tank, the inlet of the expansion water tank is connected to the overflow port, and the outlet of the expansion water tank is connected to the inlet of the electronic water pump.

[0050] As an example, an overflow port is designed on the cylinder head, and an expansion water tank is arranged between the overflow port of the cylinder head and the inlet of the electronic water pump. The coolant overflowing from the cylinder head is returned to the cylinder body through the electronic water pump to achieve the purpose of water replenishment.

[0051] In one embodiment, the engine cooling system further comprises an oil cooler, one end of the oil cooler is connected to the third outlet of the cylinder block, and the other end of the oil cooler is connected to the second inlet of the cylinder block.

[0052] As an example, the engine cooling system also includes an oil cooler, one end of the oil cooler is connected to the third outlet of the cylinder body, and the other end of the oil cooler is connected to the second inlet of the cylinder body, which is used to cool the engine oil in the cylinder body to ensure the cooling effect of the engine oil.

[0053] The existing engine cooling system has the problem of incompatibility of different modes when performing mode control. For example, after the engine is shut down, if the cooling system stops flowing, the high temperature of 800-900℃ inside the supercharger will boil the nearby coolant in a short time, so it is generally required to run afterward. However, in the process of cooling the coolant out of the radiator, the coolant in other parts of the engine will also be taken out to the radiator for heat exchange, and the overall heat dissipation is relatively large. However, due to the large number of start-stop conditions of hybrid vehicles, if the temperature drops too fast after each shutdown, the next start needs to be reheated, and the low friction effect cannot be maintained. It is also very unfavorable to avoid oil dilution in cold areas. Therefore, there is a high demand for heat preservation, that is, the two requirements of supercharger post-operation and oil heat preservation are contradictory, and there is no need to achieve both. For another example, during the shutdown of the hybrid vehicle engine, there is still heat inside the body. If there is a need for warm air, the flow can be maintained to a certain extent to utilize the internal waste heat, but the utilization of waste heat from warm air generally conflicts with the need for oil heat preservation and cannot be achieved.

[0054] In one embodiment, an engine controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a diagnostic control method for an engine cooling system in the following embodiments is implemented, for example: Figure 2 S201-S204 as shown, or Figures 3 to 13 To avoid repetition, it will not be described here.

[0055] In one embodiment, an engine cooling system is provided, comprising a cylinder block, a cylinder head, an electronic water pump, a warm air branch, a temperature control branch, a first temperature sensor, a second temperature sensor, a third temperature sensor and the above-mentioned engine controller; the cylinder block and the cylinder head cooperate to form a cylinder circulation branch; the warm air branch is arranged between the first outlet of the cylinder head and the inlet of the electronic water pump, and comprises a bypass valve and a warm air core arranged in series; the temperature control branch comprises a temperature control module and a radiator, the inlet of the temperature control module is connected to the first outlet of the cylinder block, the outlet of the temperature control module is connected to the inlet of the electronic water pump, or the outlet of the temperature control module is connected to the inlet of the electronic water pump through the radiator; The outlet is connected to the first inlet of the cylinder body; the first temperature sensor is arranged on the first outlet of the cylinder body, and is used to collect the outlet water temperature of the engine; the second temperature sensor is arranged on the first inlet of the cylinder body, and is used to collect the inlet water temperature of the engine; the third temperature sensor is arranged on the cylinder body, and is used to collect the engine oil temperature of the engine; the engine controller is connected to the first temperature sensor, the second temperature sensor, the third temperature sensor, the temperature control module, the bypass valve, the temperature control module and the electronic water pump, and is used to perform diagnostic control according to the outlet water temperature, the inlet water temperature and the engine oil temperature, so as to realize the diagnostic control method of the engine cooling system in the following embodiments, for example Figure 2 S201-S204 as shown, or Figures 3 to 13 To avoid repetition, it will not be described here.

[0056] In one embodiment, a vehicle is provided, comprising the engine cooling system in the above embodiment.

[0057] The first temperature sensor is arranged between the second outlet of the cylinder body and the temperature control module, and the outlet water temperature T1 collected by it can be sent to the engine controller. The second temperature sensor is arranged between the outlet of the electronic water pump and the first inlet of the cylinder body, and the inlet water temperature T2 collected by it can be sent to the engine controller. The third temperature sensor is arranged on the cylinder body, and the oil temperature T3 collected by it can be sent to the engine controller. In this example, the engine controller can determine whether the switching condition corresponding to the target mode is met according to the collected outlet water temperature T1, inlet water temperature T2 and oil temperature T3. If the switching condition of the target mode is met, the temperature control module is controlled to work based on the first target opening, the bypass valve is controlled to work based on the second target opening, and the electronic water pump is controlled to work based on the target speed, so that the engine enters different target modes to achieve the effect of being compatible with the requirements of different target modes. In addition, the engine controller can also perform fault diagnosis and control according to the collected outlet water temperature T1, inlet water temperature T2 and oil temperature T3 to ensure the normal operation of the engine.

[0058] In this embodiment, the EMS can control the engine to enter any of the working modes such as pre-treatment mode, first heat engine mode, second heat engine mode, shunt mode, normal working mode, overheating mode, heat preservation and waste heat utilization mode, start-stop operation mode and hybrid overheating operation mode according to actual conditions. Among them, the pre-treatment mode refers to the first mode in which the engine cooling system starts to work. The first heat engine mode is a mode for quickly heating the coolant in the engine. The second heat engine mode is a mode for uniformly heating the coolant in the engine, which is a mode after the first heat engine mode. The shunt mode is a mode in which the cylinder block and the cylinder head are shunted; the normal working mode refers to a working mode in which the cylinder block and the cylinder head both reach the normal working temperature and the temperature distribution is relatively uniform. The overheating mode refers to a working mode in which the cylinder block and the cylinder head are relatively high and there is a risk of overheating. The heat preservation and waste heat utilization mode is a mode for realizing waste heat utilization or heat preservation function. The start-stop operation mode refers to the operation mode after the engine is started and stopped. The hybrid overheating operation mode refers to the operation mode after the engine is hybridized. In this example, when the EMS determines that the engine is in different operating modes, it can use different fault diagnosis control strategies to perform fault diagnosis and control processing.

[0059] In one embodiment, if Figure 2 As shown, a diagnosis control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnosis control method for the engine cooling system includes:

[0060] S201: when the engine is in the current mode, obtaining measured data, the measured data including the measured temperature of the engine, the measured temperature of the engine being at least one of the outlet water temperature, the inlet water temperature and the oil temperature;

[0061] S202: Obtaining a target temperature threshold corresponding to the current mode;

[0062] S203: Obtaining a fault detection result according to the actual engine temperature and a target temperature threshold corresponding to the current mode;

[0063] S204: When the fault detection result is that a fault exists, determine the engine fault level, and execute a target control strategy corresponding to the engine fault level.

[0064] The current mode refers to the working mode that the engine is in at the current moment. As an example, the current mode can be any one of the pre-treatment mode, the first heat engine mode, the second heat engine mode, the shunt mode, the normal working mode, the overheating mode, the heat preservation and waste heat utilization mode, the start-stop operation mode, and the hybrid overheating operation mode.

[0065] Among them, measured data refers to data collected in real time. As an example, the measured data may include engine measured data, and the engine measured temperature refers to the temperature related to the engine collected in real time. The engine measured temperature includes at least one of the outlet water temperature T1, the inlet water temperature T2 and the oil temperature T3. In this example, the measured data may also include engine speed, which refers to the speed of the engine collected in real time during operation, which can be represented by EngSpd. Engine torque refers to the torque of the engine during operation, which can be represented by EngTorq. Ambient temperature refers to the temperature of the environment in which the engine is located collected in real time, which can be represented by Tamb.

[0066] As an example, in step S201, when the engine is in the current mode, that is, when the engine is in any of the pretreatment mode, the first heat engine mode, the second heat engine mode, the diversion mode, the normal operation mode, the overheating mode, the insulation and waste heat utilization mode, the start-stop operation mode and the hybrid overheating operation mode, the EMS can obtain the measured data such as the engine measured temperature through the CAN bus, or obtain the measured data such as the engine speed EngSpd, the engine torque EngTorq, the ambient temperature Tamb and the engine measured temperature, so as to perform fault diagnosis based on the obtained measured data.

[0067] The target temperature threshold corresponding to the current mode refers to the temperature threshold used to evaluate whether a fault condition is met in the current mode.

[0068] As an example, in step S202, when the engine is in the current mode, the EMS can obtain a preset target temperature threshold, or it can determine measured data such as engine speed EngSpd, engine torque EngTorq and ambient temperature Tam_amb as input parameters based on a preconfigured temperature threshold determination logic, and process these input parameters to quickly determine the target temperature threshold corresponding to the current mode, so that the target temperature threshold is related to measured data such as engine speed EngSpd, engine torque EngTorq and ambient temperature Tam_amb, thereby ensuring the dynamics and accuracy of the target temperature threshold and making it related to the engine operating conditions and ambient temperature, which helps to ensure the accuracy of subsequent fault diagnosis.

[0069] Among them, the engine fault level is a pre-set level reflecting the severity of the fault. As an example, the engine fault level can be set to five levels, which are set to the first fault level, the second fault level, the third fault level, the fourth fault level and the fifth fault level in order from small to large according to the severity of the fault. The target control strategy refers to a pre-set processing strategy that matches the engine fault level. Among them, the first fault level is the fault level with the smallest fault severity, and its corresponding target control strategy is to record the engine fault level without other processing. The second fault level is the fault level with a smaller fault severity, and its corresponding target control strategy is to record the engine fault level and perform risk processing. The third fault level is the fault level with a medium fault severity, and its corresponding target control strategy is to record the engine fault level and perform risk prompts. The fourth fault level is the fault level with a larger fault severity, and its corresponding target control strategy is to record the engine fault level and control the engine to enter the speed limit condition. The fifth fault level is the fault level with the largest fault severity, and its corresponding target control strategy is to record the engine fault level and control the engine to enter the idle condition. Idle mode refers to the state where the engine is running without load. For example, when you park your car in a shopping mall and wait for someone, you do not turn off the engine. This is an idle mode. The idle mode can be either an economic mode or a sports mode.

[0070] As an example, in step S203, after obtaining the target temperature threshold corresponding to the current mode, the EMS may compare the real-time measured engine temperature with the target temperature threshold corresponding to the current mode, and determine whether the fault condition corresponding to the current mode is met based on the comparison result, thereby obtaining the fault detection result.

[0071] For example, when the target temperature threshold corresponding to the current mode is the maximum temperature threshold of the current mode, when the actual measured temperature of the engine is greater than the maximum temperature threshold, it is determined that it meets the fault condition of the current mode, and a fault detection result indicating that a fault exists is obtained; when the actual measured temperature of the engine is not greater than the maximum temperature threshold, it is determined that it does not meet the fault condition of the current mode, and a fault detection result indicating that a fault does not exist is obtained.

[0072] For another example, when the target temperature threshold corresponding to the current mode is the minimum temperature threshold of the current mode, when the actually measured temperature of the engine is less than the minimum temperature threshold, it is determined that it meets the fault condition of the current mode, and a fault detection result indicating that a fault exists is obtained; when the actually measured temperature of the engine is not less than the minimum temperature threshold, it is determined that it does not meet the fault condition of the current mode, and a fault detection result indicating that a fault does not exist is obtained.

[0073] The target control strategy corresponding to the current mode refers to a strategy for handling existing faults in the current mode.

[0074] As an example, in step S204, after obtaining the fault detection result indicating that a fault exists, the EMS can determine the engine fault level, specifically based on the comparison result between the actual engine temperature and the target temperature threshold, and then execute the target control strategy corresponding to the engine fault level to handle the engine faults existing in different modes and ensure the normal operation of the engine.

[0075] In this embodiment, based on the comparison result between the actual engine temperature and the target temperature threshold corresponding to the current mode, it is first quickly evaluated whether the engine has a fault in the current mode to obtain a fault detection result. When the fault detection result is that a fault exists, the engine fault level is determined and the target control strategy corresponding to the engine fault level is executed to ensure the accuracy of fault diagnosis and control, thereby ensuring the normal operation of the engine.

[0076] In one embodiment, the measured data also includes engine speed, engine torque and ambient temperature;

[0077] Step S202, i.e. obtaining the target temperature threshold corresponding to the current mode, includes:

[0078] S2021: determining engine power according to engine speed and engine torque;

[0079] S2022: According to the ambient temperature and the engine power, query the target temperature mapping table corresponding to the current mode to obtain the target temperature threshold corresponding to the current mode.

[0080] As an example, in step S2021, when the engine is in the current mode, the EMS can calculate the engine power Peng_M0 based on the acquired engine speed EngSpd and engine torque EngTorq. In this example, the engine power can be calculated using the power calculation formula Peng_M0=EngSpd*EngTorq / 9550.

[0081] The target temperature mapping table refers to a three-dimensional mapping table that is preset and corresponds to the current mode and is used for mapping relationships between the ambient temperature Tamb, the engine power Peng_M0, and the temperature threshold corresponding to the current mode.

[0082] As an example, in step S2022, when the engine is in the current mode, the EMS may query a preset target temperature mapping table corresponding to the current mode based on the ambient temperature Tamb and the engine power Peng_M0, obtain a temperature threshold corresponding to the ambient temperature Tamb and the engine power Peng_M0 from the target temperature mapping table, and determine it as the target temperature threshold corresponding to the current mode. In this example, the target temperature threshold is a temperature threshold determined by the table lookup in the current mode for evaluating whether a fault condition is met.

[0083] In this example, the engine power Peng_M0 is first calculated based on the engine speed EngSpd and the engine torque EngTorq; then a table is looked up based on the ambient temperature Tamb and the engine power Peng_M0. This can ensure that the target temperature threshold corresponding to the current mode is quickly obtained, and the dynamics and accuracy of the target temperature threshold are guaranteed, so that it is related to the engine operating conditions and ambient temperature, which helps to ensure the accuracy of subsequent fault diagnosis.

[0084] In one embodiment, if Figure 3 As shown, a diagnosis control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnosis control method for the engine cooling system includes:

[0085] S301: when the engine is in a pre-processing mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature and oil temperature;

[0086] S302: acquiring a first maximum allowable temperature difference value corresponding to the preprocessing mode according to the engine speed, the engine torque and the ambient temperature;

[0087] S303: Obtaining a fault detection result according to the outlet water temperature, the inlet water temperature, and the first maximum allowable temperature difference corresponding to the pretreatment mode;

[0088] S304: When the fault detection result is that a fault exists, determine the engine fault level according to the ambient temperature and the oil temperature, and execute a target control strategy corresponding to the engine fault level.

[0089] Among them, step S301 is a specific implementation of step S201, step S302 is a specific implementation of step S202, step S303 is a specific implementation of step S203, and step S304 is a specific implementation of step S204.

[0090] As an example, in step S301, when the engine is in the pre-processing mode, the EMS needs to obtain measured data such as engine speed EngSpd, engine torque EngTorq, ambient temperature Tamb, outlet water temperature T1 and inlet water temperature T2, so as to perform fault diagnosis based on the above measured data.

[0091] As an example, in step S302, the EMS can determine the first maximum allowable temperature difference value corresponding to the pre-processing mode according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Ta_amb, and determine it as the target temperature threshold value corresponding to the pre-processing mode. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, based on the ambient temperature Ta_amb and the engine power Peng_M0, the EMS queries the first allowable temperature difference mapping table corresponding to the pre-processing mode, obtains the first maximum allowable temperature difference value corresponding to the ambient temperature Ta_amb and the engine power Peng_M0 from the first allowable temperature difference mapping table, and determines it as the first maximum allowable temperature difference value corresponding to the pre-processing mode. Among them, the first allowable temperature difference mapping table is a three-dimensional mapping table pre-set in the pre-processing mode to reflect the mapping relationship between the ambient temperature Ta_amb, the engine power Peng_M0 and the first maximum allowable temperature difference value, which can be represented by Map_gT_delta_M0. The first maximum allowable temperature difference value corresponding to the preprocessing mode refers to the maximum temperature difference value allowed to be achieved in the preprocessing mode, and can be represented by gTdelta_M0.

[0092] As an example, in step S303, when the engine is in the pre-treatment mode, the EMS can obtain the measured temperature difference between the inlet and outlet of the engine based on the outlet water temperature T1 and the inlet water temperature T2 of the engine, and then compare the measured temperature difference with the actual temperature difference. Based on the comparison result of the two, it is determined whether there is a fault in the engine in the pre-treatment mode and the fault detection result is obtained.

[0093] In one embodiment, step S303, i.e., obtaining a fault detection result according to the outlet water temperature T1, the inlet water temperature T2 and the first maximum allowable temperature difference corresponding to the pretreatment mode, includes:

[0094] S3031: Obtaining a measured temperature difference value according to the outlet water temperature T1 and the inlet water temperature T2;

[0095] S3032: If the measured temperature difference value is not less than the first maximum allowable temperature difference value corresponding to the preprocessing mode, a fault detection result indicating that a fault exists is obtained;

[0096] S3033: If the measured temperature difference value is less than the first maximum allowable temperature difference value corresponding to the preprocessing mode, a fault detection result indicating that no fault exists is obtained.

[0097] As an example, in step S3031, after the engine management system (EMS) obtains the outlet water temperature T1 and the inlet water temperature T2 of the engine, it calculates the measured temperature difference value T_delta of the engine based on the outlet water temperature T1 and the inlet water temperature T2 of the engine. In this example, T_delta = T1 - T2; then, it compares the measured temperature difference value T_delta with the first maximum allowable temperature difference value gTdelta_M0 corresponding to the preprocessing mode, so as to evaluate whether there is a fault in the engine according to the comparison result. This measured temperature difference value T_delta can effectively reflect the temperature difference between the engine outlet and the engine inlet.

[0098] As an example, in step S3032, when the measured temperature difference value T_delta is not less than the first maximum allowable temperature difference value gTdelta_M0 corresponding to the preprocessing mode, that is, when T_delta ≥ gTdelta_M0, the EMS determines that the measured temperature difference value T_delta is large and exceeds its allowed maximum value, indicating that there is a risk of heat leakage in the engine cooling system, and obtains a fault detection result of a fault.

[0099] As an example, in step S3033, when the measured temperature difference value T_delta is less than the first maximum allowable temperature difference value gTdelta_M0 corresponding to the preprocessing mode, that is, when T_delta < gTdelta_M0, the EMS determines that the measured temperature difference value T_delta is small and does not reach its allowed maximum value, indicating that there is no risk of heat leakage in the engine cooling system, and obtains a fault detection result of no fault.

[0100] In this embodiment, when the engine is in the preprocessing mode, its temperature control module closes the branch where the radiator is located, and the bypass valve closes the branch where the heater core is located. That is to say, both of these two heat dissipation components, the radiator and the heater core, are closed. At this time, according to the comparison result between the measured temperature difference value T_delta and the first maximum allowable temperature difference value gTdelta_M0, it is determined whether there is a risk of heat leakage in the engine cooling system, so as to obtain a fault detection result of whether there is a fault. It can be understood that when the fault detection result is a risk of heat leakage and both of these two heat dissipation components, the radiator and the heater core, are closed, it can be deduced that this risk of heat leakage can be understood as the risk brought by the engine itself fault. Therefore, it can be determined whether there is a fault in the engine.

[0101] As an example, in step S304, when the fault detection result is a fault, the EMS needs to further evaluate and determine the engine fault level according to the measured data collected in real time, including but not limited to the ambient temperature T_amb and the oil temperature T3, and then execute the target control strategy corresponding to the engine fault level, so as to achieve the purpose of fault diagnosis and control, thereby ensuring the normal operation of the engine in the preprocessing mode.

[0102] In one embodiment, step S304, i.e., when the fault detection result is that a fault exists, determining the engine fault level according to the ambient temperature and the oil temperature T3, and executing the target control strategy corresponding to the engine fault level, includes:

[0103] S3041: When the fault detection result is that a fault exists, query the oil dilution risk mapping table corresponding to the pre-processing mode according to the ambient temperature and the oil temperature T3 to obtain the oil dilution risk value;

[0104] S3042: If the oil dilution risk value is not less than the first dilution risk threshold, the engine fault level is determined to be the third fault level, the control instrument outputs the first fault prompt information, and the vehicle driving mode is controlled to enter the sports mode;

[0105] S3043: If the oil dilution risk value is less than the first dilution risk threshold, the engine fault level is determined to be the first fault level, and the engine fault level is recorded.

[0106] Among them, the oil dilution risk mapping table corresponding to the pretreatment mode refers to a three-dimensional mapping table used to reflect the mapping relationship between the ambient temperature Tamb, the oil temperature T3 and the oil dilution risk value in the pretreatment mode, which can be represented by Map_oil_risk_M0; accordingly, the oil dilution risk value obtained by looking up the table can be represented by Oil_risk_M0.

[0107] As an example, when the engine is in the pre-treatment mode and the fault detection result is that there is a fault, the EMS can obtain the ambient temperature T_amb and the oil temperature T3, query the oil dilution risk mapping table Map_oil_risk_M0 corresponding to the pre-treatment mode according to the ambient temperature T_amb and the oil temperature T3, and obtain the oil dilution risk value Oil_risk_M0 corresponding to the ambient temperature T_amb and the oil temperature T3 from the oil dilution risk mapping table Map_oil_risk_M0. In this example, the oil dilution risk value Oil_risk_M0 is obtained by looking up the table based on the ambient temperature T_amb and the oil temperature T3, which not only ensures the efficiency of obtaining the oil dilution risk value Oil_risk_M0, but also ensures its dynamicity and accuracy.

[0108] The first dilution risk threshold is a preset threshold for evaluating whether there is an oil dilution risk, and can be represented by Oil_risk_tres_M0.

[0109] As an example, after the Engine Management System (EMS) obtains the oil dilution risk value Oil_risk_M0, it can compare the oil dilution risk value Oil_risk_M0 with the first dilution risk threshold Oil_risk_tres_M0. When the oil dilution risk value Oil_risk_M0 is not less than the first dilution risk threshold Oil_risk_tres_M0 (i.e., Oil_risk_M0 ≥ Oil_risk_tres_M0), it is determined that the oil dilution risk value Oil_risk_M0 is relatively large, and it is determined that the oil dilution risk is relatively high. At this time, the fault bit Bit_error = M0_leakage can be set, the engine fault level is determined to be the third fault level Err_lev = 3, and the first fault prompt message is output. For example, "There is a risk of internal leakage in the cooling system, please check" can be output. At the same time, the EMS can also switch the vehicle driving mode to the sport mode to increase the power demand, and correct the target idle speed upward to idle_high to improve the engine's work and heat generation capacity. Vehicles of general models are equipped with an economy mode, a comfort mode, and a sport mode. The main difference among these modes lies in the dynamic output response of the whole vehicle when the accelerator pedal and the brake pedal are pressed. Different modes are determined based on the enthusiasm of the power output response and the heat generation. The sport mode is the mode with the most active power output and greater heat generation.

[0110] As an example, after the Engine Management System (EMS) obtains the oil dilution risk value Oil_risk_M0, it can compare the oil dilution risk value Oil_risk_M0 with the first dilution risk threshold Oil_risk_tres_M0. When the oil dilution risk value Oil_risk_M0 is less than the first dilution risk threshold Oil_risk_tres_M0 (i.e., Oil_risk_M0 < Oil_risk_tres_M0), it is determined that the oil dilution risk value Oil_risk_M0 is relatively small, and it is determined that the oil dilution risk is relatively low. At this time, the fault bit Bit_error = M0_leakage can be set, the engine fault level is determined to be the first fault level, and the engine fault level is recorded. In this example, when the engine fault level is the first fault level, the impact of the fault on the engine and the vehicle operation is relatively small and can be ignored. Therefore, only the fault code corresponding to the engine fault level is stored internally, and no prompt message needs to be output to avoid interfering with the normal driving of the user.

[0111] In one embodiment, as Figure 4 shown, a diagnostic control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnostic control method for the engine cooling system includes:

[0112] S401: when the engine is in a first warm-up mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature and engine oil temperature;

[0113] S402: determining a first minimum engine oil temperature rise value corresponding to a first heat engine mode according to an engine speed, an engine torque and an ambient temperature;

[0114] S403: acquiring a fault detection result according to the engine oil temperature and a first engine oil minimum temperature rise value corresponding to the first heat engine mode;

[0115] S404: When the fault detection result is that a fault exists, determining that the engine fault level is a second fault level, and controlling the engine to enter a first emergency mode.

[0116] Among them, step S401 is a specific implementation of step S201, step S402 is a specific implementation of step S202, step S403 is a specific implementation of step S203, and step S404 is a specific implementation of step S204.

[0117] As an example, in step S401, when the EMS is in the first heat engine mode, the coolant in the engine cooling system stops flowing, that is, it is determined that the cylinder block and the cylinder head are in zero flow mode, and the heat will be quickly focused inside the cylinder block and the cylinder head. At this time, it is necessary to obtain measured data such as engine speed EngSpd, engine torque EngTorq, ambient temperature Tamb and oil temperature T3, so as to perform fault diagnosis based on the above measured data.

[0118] As an example, in step S402, when the engine is in the first heat engine mode, the EMS needs to determine the first minimum oil temperature rise value corresponding to the first heat engine mode according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Ta_amb, and determine it as the target temperature threshold corresponding to the first heat engine mode. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, based on the ambient temperature Ta_amb and the engine power Peng_M0, the EMS queries the first oil temperature rise mapping table corresponding to the first heat engine mode, obtains the first oil minimum temperature rise value corresponding to the ambient temperature Ta_amb and the engine power Peng_M0 from the first oil temperature rise mapping table, and determines it as the first oil minimum temperature rise value corresponding to the first heat engine mode. Among them, the first oil temperature rise mapping table is a three-dimensional mapping table pre-set in the first heat engine mode to reflect the mapping relationship between the ambient temperature Ta_amb, the engine power Peng_M0 and the oil minimum temperature rise value, which can be represented by Map_T3rise_M1. The first minimum engine oil temperature rise value corresponding to the first heat engine mode refers to the minimum engine oil temperature rise value of the engine oil temperature T3 allowed to change in the first heat engine mode, and can be represented by min_Trise_spd.

[0119] As an example, in step S403, when the engine is in the first heat engine mode, the EMS can calculate the measured oil change value within a specific time period based on the real-time collected engine oil temperature T3, and then compare the measured oil change value with the first oil minimum temperature rise value min_Trise_spd corresponding to the first heat engine mode. Based on the comparison result of the two, it is determined whether there is a fault in the engine in the first heat engine mode to obtain the fault detection result.

[0120] In one embodiment, step S303, i.e., obtaining a fault detection result according to the engine oil temperature T3 and the first engine oil minimum temperature rise value corresponding to the first heat engine mode, includes:

[0121] S4031: Obtaining a measured oil change value according to all oil temperatures T3 within the cycle duration;

[0122] S4032: If the measured engine oil change value is less than the first engine oil minimum temperature rise value, updating the first abnormality number;

[0123] S4033: If the first abnormal number is greater than the first number threshold, a fault detection result indicating that a fault exists is obtained;

[0124] S4034: If the measured oil change value is not less than the first oil minimum temperature rise value, or the first abnormal number is not greater than the first number threshold, a fault detection result indicating that no fault exists is obtained.

[0125] The cycle duration is a preset duration for calculating temperature changes, which may be represented by t_Cal. For example, the cycle duration may be set to 0.1 s.

[0126] As an example, in step S4031, the EMS can obtain the oil temperature array T3_M[dim1] formed by all the oil temperatures T3 collected by the engine within the cycle time t_Cal from the measured temperature of the engine; calculate the measured oil change value corresponding to the cycle time according to all the oil temperatures T3 within the cycle time; then, compare the measured oil change value T3_diff_M with the first oil minimum temperature rise value min_Trise_spd corresponding to the first heat engine mode, so as to evaluate whether the engine has a fault in the first heat engine mode according to the comparison result. The measured oil change value refers to the change value of the oil temperature T3 collected within the cycle time. When the engine is in the first heat engine mode, the oil temperature T3 increases rapidly. At this time, the measured oil change value is the measured oil temperature rise value.

[0127] In this example, EMS can divide the values ​​in the oil temperature array T3_M[dim1] formed by all the oil temperatures T3 collected within the cycle duration t_Cal into two segments, namely T3_M[0~pro] and T3_M[pro+1,dim1-1]; then, calculate the average values ​​of the two segments respectively, and determine them as T3_M_pre=ave(T3_M[0~pro]) and T3_M_pro=ave(T3_M[pro+1,dim1-1]); finally, according to the average values ​​of the two segments, calculate the actual oil change value T3_diff_M corresponding to the cycle duration, that is, T3_diff_M=T3_M_pro-T3_M_pre. For example, the loop duration is 0.1s, 10 values ​​are recorded per second, and the array length is set to 10. At this time, the first 5 numbers of the T3_M[dim1] array are averaged, and the last 5 numbers of the T3_M[dim1] array are averaged to obtain T3_M_pre and T3_M_pro. Then, based on T3_M_pre and T3_M_pro, the actual oil change value T3_diff_M is calculated.

[0128] The first abnormal number refers to the abnormal number counted in the first heat engine mode, which can be represented by abn_M1. The first number threshold is a preset threshold for evaluating whether the first abnormal number reaches the fault standard, which can be represented by abn_tres_M1.

[0129] As an example, in step S4032, when the measured oil change value T3_diff_M is less than the first minimum oil temperature rise value min_Trise_spd (i.e., T3_diff_M < min_Trise_spd), the EMS determines that the measured oil change value T3_diff_M is small and does not reach the first minimum oil temperature rise value required in the first engine warm-up mode, indicating that the engine warm-up effect does not meet the standard. At this time, it can be determined that the engine is abnormal, and the first abnormal count abn_M1 needs to be updated, that is, abn_M1 = abn_M1 + 1; then, the updated first abnormal count abn_M1 is compared with the pre-set first count threshold abn_tres_M1 to evaluate whether the engine has a fault according to the comparison result.

[0130] As an example, in step S4033, when the first abnormal count abn_M1 is greater than the pre-set first count threshold abn_tres_M1 (i.e., abn_M1 > abn_tres_M1), the EMS can determine that the number of times the engine detects an abnormality is large, reaching the evaluation condition for determining that the engine has a fault. Therefore, the fault detection result indicating a fault can be obtained.

[0131] As an example, in step S4033, when the measured oil change value T3_diff_M is not less than the first minimum oil temperature rise value min_Trise_spd (i.e., T3_diff_M ≥ min_Trise_spd), the EMS determines that the measured oil change value T3_diff_M is large and reaches the first minimum oil temperature rise value required in the first engine warm-up mode, indicating that the engine warm-up effect meets the standard. Therefore, the fault detection result indicating no fault can be obtained. Or, when the first abnormal count abn_M1 is not greater than the pre-set first count threshold abn_tres_M1 (i.e., abn_M1 ≤ abn_tres_M1), the EMS can determine that the number of times the engine detects an abnormality is small and does not reach the evaluation condition for determining that the engine has a fault. Therefore, the fault detection result indicating no fault can be obtained.

[0132] In this embodiment, when the engine is in the first engine warm-up mode, the temperature control module is controlled to be turned off, the bypass valve is closed, and the electronic water pump is controlled to stop working. At this time, the coolant in the engine does not flow, and the oil temperature T3 rises rapidly. At this time, according to the comparison result between the measured oil change value T3_diff_M and the first minimum oil temperature rise value min_Trise_spd, it can be determined whether there is an abnormality in the change of the engine oil temperature T3; when there is an abnormality, according to the comparison result between the first abnormal count and the first count threshold, the fault detection result indicating whether there is a fault can be determined, so as to effectively diagnose whether the engine has a fault in the first engine warm-up mode and ensure the accuracy of the diagnosis result.

[0133] The first emergency mode refers to an emergency mode in which the engine is in the first heat engine mode.

[0134] As an example, in step S204, when the engine is in the first heat engine mode and its fault detection result is a fault, the EMS can determine that the fault bit Bit_error=M0_leakage can be set, and the engine fault level is determined to be the second fault level Err_lev=2. Since when the engine fault level is the second fault level, the impact of the fault on the engine and the whole vehicle operation is small, at this time, there is no need to output prompt information to avoid interfering with the user's normal driving. However, in order to avoid risks, emergency risk processing can be performed. Specifically, the temperature control module, the bypass valve and the electronic water pump can be controlled to make the engine enter the first emergency mode. Specifically, the first emergency opening n_safe_tmm_M1 is determined as the first target opening of the temperature control module to control the operation of the temperature control module; the second emergency opening n_safe_bpv_M1 is determined as the second target opening of the bypass valve to control the operation of the bypass valve; the first emergency speed n_safe_ewp_M1 is determined as the target speed of the electronic water pump to control the operation of the electronic water pump. The sizes of the first emergency opening n_safe_tmm_M1, the second emergency opening n_safe_bpv_M1 and the first emergency speed n_safe_ewp_M1 here depend on the vehicle model, and are values ​​determined after calibration tests are performed on vehicles of different models.

[0135] In one embodiment, after step S404, that is, after controlling the engine to enter the first emergency mode, the diagnosis control method of the engine cooling system further includes:

[0136] S4051: monitoring the emergency operation time corresponding to the engine entering the first emergency mode;

[0137] S4052: If the emergency operation duration is greater than the first duration threshold, the engine is controlled to enter the second heat engine mode.

[0138] The emergency operation duration refers to the operation duration of the engine after entering the first emergency mode, which can be represented by Tc. The first duration threshold refers to the preset duration threshold used to evaluate whether the emergency operation duration reaches a longer standard to exit the first emergency mode, which can be represented by t_safe_M1.

[0139] As an example, after the engine enters the first emergency mode, the EMS needs to monitor the emergency operation time Tc corresponding to the engine entering the first emergency mode in real time, and compare the emergency operation time Tc with the pre-set first time threshold t_safe_M1; when the emergency operation time Tc is greater than the first time threshold t_safe_M1 (i.e., Tc>t_safe_M1), it is determined that the time to enter the first emergency mode is long, and the first emergency mode can be exited, and the second heat engine mode can be forced to enter, that is, the mode of low flow of the cylinder head and zero flow of the cylinder body is entered, so that the cylinder body continues to accumulate heat, ensuring that the oil temperature T3 rises rapidly, thereby achieving the purpose of uniform heat engine. In this example, when the engine enters the first emergency mode, based on the comparison result of its emergency operation time and the first time threshold, it is evaluated whether it is necessary to forcibly switch to the second heat engine mode, complete the risk response of failures in the first heat engine mode, and ensure the normal operation of the engine.

[0140] In one embodiment, after step S404, that is, after controlling the engine to enter the first emergency mode, the diagnosis control method of the engine cooling system further includes:

[0141] S4061: Obtaining a measured oil change value according to all oil temperatures T3 within the cycle duration;

[0142] S4062: If the measured oil change value is less than the temperature fluctuation threshold, update the second abnormality number;

[0143] S4063: If the second abnormal number is greater than the second number threshold, the engine fault level is determined to be the third fault level, and the engine is controlled to enter the diversion mode.

[0144] The temperature fluctuation threshold is a preset threshold for limiting sensor fluctuation, which can be determined according to the accuracy of the third temperature sensor and is represented by T3_aCC_M1.

[0145] As an example, in step S4061, after the engine enters the first emergency mode, the EMS can obtain the oil temperature array T3_M[dim1] formed by all the oil temperatures T3 collected by the engine within the cycle time t_Cal; calculate the measured oil change value corresponding to the cycle time according to all the oil temperatures T3 within the cycle time; then, compare the measured oil change value T3_diff_M with the preset temperature fluctuation threshold T3_aCC_M1, so as to evaluate whether it is necessary to switch to the diversion mode according to the comparison result. The measured oil change value can effectively reflect the change of the oil temperature T3 of the engine.

[0146] Among them, the second abnormal count refers to the abnormal count statistically obtained in the first engine warm-up mode, which can be represented by abn2_M1. The second count threshold is a threshold set in advance for evaluating whether the second abnormal count reaches the failure standard, which can be represented by abn2_tres_M1.

[0147] As an example, in step S4062, when the measured engine oil change value T3_diff_M is less than the temperature fluctuation threshold T3_aCC_M1 (i.e., T3_diff_M < T3_aCC_M1), the EMS determines that the measured engine oil change value T3_diff_M used in the first emergency mode is relatively small, indicating that the engine warm-up effect does not meet the standard. It can be determined that the engine is abnormal, and the second abnormal count abn2_M1 needs to be updated, that is, abn2_M1 = abn2_M1 + 1. Then, the updated second abnormal count abn2_M1 is compared with the pre-set second count threshold abn2_tres_M1 to determine whether to control the engine to switch to the diversion mode Set_model = 3 according to the comparison result.

[0148] As an example, in step S4063, when the updated second abnormal count abn2_M1 is greater than the pre-set second count threshold abn2_tres_M1 (i.e., abn2_M1 > abn2_tres_M1), it can be determined that the number of times the engine detects abnormalities is relatively large, meeting the failure handling condition for switching to the diversion mode Set_model = 3. At this time, the engine can be controlled to enter the diversion mode to achieve the purpose of self-controlling the temperature control module, bypass valve, and electronic water pump according to the engine working conditions, ensuring the uniformity of the internal temperature of the cylinder block and cylinder head.

[0149] In one embodiment, after step S404, that is, after controlling the engine to enter the first emergency mode, the diagnostic control method of the engine cooling system further includes:

[0150] S4071: Compare the outlet water temperature T1 with the first outlet water temperature threshold and the second outlet water temperature threshold, and compare the inlet water temperature T2 with the first inlet water temperature threshold and the second inlet water temperature threshold;

[0151] S4072: If the outlet water temperature T1 is between the first outlet water temperature threshold and the second outlet water temperature threshold, or the inlet water temperature T2 is between the first inlet water temperature threshold and the second inlet water temperature threshold, it is determined that the engine failure level is the fourth failure level, and the engine is controlled to enter the speed limit working condition;

[0152] S4073: If the outlet water temperature T1 is greater than or equal to the second outlet water temperature threshold, or the inlet water temperature T2 is greater than or equal to the second inlet water temperature threshold, determine that the engine fault level is the fifth fault level, and control the engine to enter the idle condition.

[0153] Among them, the first outlet water temperature threshold is the first threshold preset in the preprocessing mode for evaluating the severity of the fault of the outlet water temperature T1, which can be represented by T1_M1_tres. The second outlet water temperature threshold is the second temperature threshold preset in the preprocessing mode for evaluating the severity of the fault of the outlet water temperature T1T2, which can be represented by T1_M1_tres2. In this example, the second outlet water temperature threshold is greater than the first outlet water temperature threshold, that is, T1_M1_tres2 > T1_M1_tres.

[0154] Among them, the first inlet water temperature threshold is the first threshold preset in the preprocessing mode for evaluating the severity of the fault of the inlet water temperature T2, which can be represented by T2_M1_tres. The second inlet water temperature threshold is the second temperature threshold preset in the preprocessing mode for evaluating the severity of the fault of the inlet water temperature T2, which can be represented by T2_M1_tres2. In this example, the second inlet water temperature threshold is greater than the first inlet water temperature threshold, that is, T2_M1_tres2 > T2_M1_tres.

[0155] As an example, when the engine is in the first warm-up mode and the fault detection result is that there is a fault, the Engine Management System (EMS) can obtain the outlet water temperature T1 and the inlet water temperature T2 of the engine; compare the outlet water temperature T1 with the first outlet water temperature threshold T1_M1_tres and the second outlet water temperature threshold T1_M1_tres2, and compare the inlet water temperature T2 with the first inlet water temperature threshold T2_M1_tres and the second inlet water temperature threshold T2_M1_tres2, so as to control the engine to enter different working conditions according to the comparison results.

[0156] Among them, the speed limit condition is the condition for restricting the engine speed.

[0157] As an example, when the outlet water temperature T1 is between the first outlet water temperature threshold T1_M1_tres and the second outlet water temperature threshold T1_M1_tres2 (that is, T1_M1_tres ≤ T1 < T1_M1_tres2), or the inlet water temperature T2 is between the first inlet water temperature threshold T2_M1_tres and the second inlet water temperature threshold T2_M1_tres2 (that is, T2_M1_tres ≤ T2 < T2_M1_tres), the EMS determines that the severity of the engine fault is relatively large, and can determine that the engine fault level is the fourth fault level, and control the engine to enter the speed limit condition to appropriately limit the engine power and avoid further aggravating the fault risk.

[0158] As an example, when the outlet water temperature T1 is greater than or equal to the second outlet water temperature threshold T1_M1_tres2 (i.e., T1≥T1_M1_tres2), or the inlet water temperature T2 is greater than or equal to the second inlet water temperature threshold T2_M1_tres2 (i.e., T2≥T2_M1_tres2), the EMS determines that the engine fault severity is the greatest, and can determine that its engine fault level is the fifth fault level, and controls the engine to enter the idle condition so that the engine works based on minimum power. In this example, the EMS can force the engine to enter the idle condition. For example, in the hybrid vehicle VCU, the power SOC is higher than the limp threshold VCU_limitSOC_M1, and the vehicle enters the EV mode until the power is lower than the limp threshold, then the engine is started, but only the idle speed can be maintained.

[0159] In one embodiment, if Figure 5 As shown, a diagnosis control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnosis control method for the engine cooling system includes:

[0160] S501: when the engine is in the second heating mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature and air conditioning demand;

[0161] S502: If the air conditioning demand is no heating demand, obtaining a first inlet water temperature minimum temperature rise value and a second engine oil temperature minimum temperature rise value corresponding to the non-heating mode according to the engine speed, the engine torque and the ambient temperature;

[0162] S503: Obtaining a fault detection result according to the outlet water temperature, the inlet water temperature, the first inlet water temperature minimum temperature rise value, and the second engine oil temperature minimum temperature rise value;

[0163] S504: When the fault detection result is that a fault exists, determine that the engine fault level is a first fault level, and record the engine fault level.

[0164] Among them, step S501 is a specific implementation of step S201, step S502 is a specific implementation of step S202, step S503 is a specific implementation of step S203, and step S504 is a specific implementation of step S204.

[0165] As an example, in step S501, when the engine is in the second heat engine mode, the EMS needs to obtain measured data such as engine speed EngSpd, engine torque EngTorq, ambient temperature Tamb, outlet water temperature T1, inlet water temperature T2 and air-conditioning demand, so as to perform fault diagnosis based on the above measured data. The air-conditioning demand here includes heating demand and no heating demand. Heating demand refers to the demand for controlling the heater core for heating treatment, which corresponds to the heating mode of the second heat engine mode; no heating demand refers to the demand for no heating treatment without controlling the heater core, which corresponds to the non-heating mode of the second heat engine mode.

[0166] As an example, in step S502, when the engine is in the second heat engine mode and the air conditioning demand is no heating demand, the EMS needs to control the air conditioning system to enter the non-heating mode. At this time, according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Tamb, the first inlet water temperature minimum temperature rise min_T2riseM2_spd and the second engine oil minimum temperature rise min_T3riseM2_spd corresponding to the non-heating mode in the second heat engine mode are determined. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, based on the ambient temperature Tamb and the engine power Peng_M0, the first inlet water temperature rise mapping table and the second engine oil temperature rise mapping table corresponding to the non-heating mode are queried to obtain the first inlet water temperature minimum temperature rise and the second engine oil minimum temperature rise corresponding to the heating mode, respectively. The first inlet water temperature rise mapping table is a three-dimensional mapping table pre-set in the second heat engine mode for reflecting the mapping relationship between the ambient temperature Tamb, the engine power Peng_M0 and the minimum inlet water temperature rise value in the heating mode, which can be represented by Map_T3rise_M2. The second engine oil temperature rise mapping table is a three-dimensional mapping table pre-set in the second heat engine mode for reflecting the mapping relationship between the ambient temperature Tamb, the engine power Peng_M0 and the minimum engine oil temperature rise value in the heating mode, which can be represented by Map_T3rise_M2.

[0167] As an example, in step S503, when the engine is in the non-heating mode of the second heat engine mode, the EMS can calculate the inlet water temperature change value and the measured oil change value within a specific time period based on the inlet water temperature T2 and the oil temperature T3 collected in real time, so as to compare the inlet water temperature change value with the first inlet water temperature minimum temperature rise value, and compare the measured oil change value with the second oil minimum temperature rise value, and determine whether the engine has a fault in the non-heating mode of the second heat engine mode based on the comparison result, and obtain the fault detection result.

[0168] In one embodiment, step S503, i.e., obtaining a fault detection result according to the outlet water temperature T1, the inlet water temperature T2, the first inlet water temperature minimum temperature rise value, and the second engine oil temperature minimum temperature rise value, includes:

[0169] S5031: Obtaining an inlet water temperature change value and a measured oil change value according to all inlet water temperatures T2 and all oil temperatures T3 within the cycle time;

[0170] S5032: If the inlet water temperature change value is greater than or equal to the first inlet water temperature minimum temperature rise value, and the measured engine oil change value is greater than or equal to the second engine oil minimum temperature rise value, then update the third abnormality number;

[0171] S5033: If the third abnormal number is greater than the third number threshold, a fault detection result indicating that a fault exists is obtained;

[0172] S5034: If the inlet water temperature change value is less than the first inlet water temperature minimum temperature rise value, the measured engine oil change value is less than the second engine oil minimum temperature rise value, or the third abnormal number is not greater than the third number threshold, then a fault detection result indicating that there is no fault is obtained.

[0173] In this example, in step S5031, the EMS can divide the values ​​in the inlet temperature array T2_M[dim1] formed by all the inlet water temperatures T2 collected within the cycle time t_Cal into two segments, namely, T2_M[0~pro] and T2_M[pro+1,dim1-1]; then, the average values ​​of the values ​​of the two segments are calculated, and they are determined as T2_M_pre=ave(T2_M[0~pro]) and T2_M_pro=ave(T2_M[pro+1,dim1-1]); finally, according to the average values ​​of the two segments, the inlet water temperature change value T2_diff_M corresponding to the cycle time is calculated, that is, T2_diff_M=

[0174] T2_M_pro-T2_M_pre.

[0175] Similarly, EMS can divide the values ​​in the oil temperature array T3_M[dim1] formed by all the oil temperatures T3 collected within the cycle duration t_Cal into two sections, namely T3_M[0~pro] and T3_M[pro+1,dim1-1]; then, calculate the average values ​​of the two sections respectively, and determine them as T3_M_pre=ave(T3_M[0~pro]), T3_M_pro=ave(T3_M[pro+1,dim1-1]); finally, according to the average values ​​of the two sections, calculate the actual oil change value T3_diff_M corresponding to the cycle duration, that is, T3_diff_M=T3_M_pro-T3_M_pre.

[0176] The third abnormal number refers to the abnormal number counted in the second heat engine mode, which can be represented by abn2_M2. The third number threshold is a preset threshold for evaluating whether the third abnormal number reaches the fault standard, which can be represented by abn2_tres_M2.

[0177] As an example, in step S5032, after obtaining the inlet water temperature change value T2_diff_M and the measured engine oil change value T3_diff_M, the EMS may compare the inlet water temperature change value T2_diff_M with the first inlet water temperature minimum temperature rise value min_T2riseM2_spd, and compare the measured engine oil change value T3_diff_M with the second engine oil minimum temperature rise value min_T3riseM2_spd; when the inlet water temperature change value T2_diff_M is greater than or equal to the first inlet water temperature minimum temperature rise value min_T2riseM2_spd (i.e., T2_diff_M ≥ min_T2riseM2_spd), the EMS may compare the inlet water temperature change value T2_diff_M with the first inlet water temperature minimum temperature rise value min_T2riseM2_spd, and compare the measured engine oil change value T3_diff_M with the second engine oil minimum temperature rise value min_T3riseM2_spd. riseM2_spd), and the measured oil change value T3_diff_M is greater than or equal to the second oil minimum temperature rise value min_T3riseM2_spd (i.e., T3_diff_M≥min_T3riseM2_spd), it is determined that the water temperature at the engine inlet is high and the oil temperature in the engine is high, and it is determined that the engine is abnormal, and the third abnormal number abn_M2 needs to be updated, that is, abn_M2=abn_M2+1; then, the updated third abnormal number abn_M2 is compared with the pre-set third number threshold abn_tres_M2, so as to determine whether there is a fault based on the comparison result.

[0178] As an example, in step S5033, when the updated third abnormal number abn_M2 is greater than the preset third number threshold abn_tres_M2 (ie, abn_M2>abn_tres_M2), the EMS can determine that the engine has detected an abnormality a large number of times, can determine that the engine has a fault, and obtain a fault detection result indicating the presence of a fault.

[0179] As an example, in step S5034, when the change value of the inlet water temperature T2_diff_M of the EMS is less than the minimum rise value of the first inlet water temperature min_T2riseM2_spd (i.e., T2_diff_M < min_T2riseM2_spd), the measured change value of the engine oil T3_diff_M is less than the minimum rise value of the second engine oil temperature min_T3riseM2_spd (i.e., T3_diff_M < min_T3riseM2_spd), or the third number of abnormal times abn_M2 is not greater than the preset third number threshold abn_tres_M2 (i.e., abn_M2 ≤ abn_tres_M2), it can be determined that the water temperature at the engine inlet or the engine oil temperature is relatively low, or although an abnormality occurs but it does not reach the fault level, and a fault detection result of no fault can be obtained.

[0180] As an example, in step S504, when the fault detection result of the EMS in the second warm-up mode is a fault, since the overall temperature of the engine is relatively low in the second warm-up mode, the severity of the fault is minimized. Therefore, its fault bit Bit_error = M2_Trise can be set, the engine fault level is determined to be the first fault level, and the engine fault level is recorded. In this example, when the engine fault level is the first fault level, the impact of the fault on the engine and the vehicle operation is relatively small and can be ignored. Therefore, only the fault code corresponding to the engine fault level is stored internally, and no prompt information needs to be output to avoid interfering with the normal driving of the user.

[0181] In an embodiment, after step S501, that is, when the engine is in the current mode and the measured data is obtained, and the measured data includes the engine speed, engine torque, ambient temperature, outlet water temperature T1, inlet water temperature T2, and air-conditioning demand, the diagnostic control method of the engine cooling system further includes:

[0182] S505: If there is a heating demand for the air-conditioning, obtain the minimum rise value of the first inlet water temperature and the minimum rise value of the second engine oil temperature corresponding to the heating mode;

[0183] S506: If the inlet water temperature T2 is less than the first minimum allowable temperature of the inlet water temperature, or the engine oil temperature T3 is less than the minimum rise value of the second engine oil temperature, control the engine to enter the diversion mode.

[0184] As an example, in step S505, when the engine is in the second heat engine mode and the air conditioning demand is heating demand, the EMS needs to control the air conditioning system to enter the heating mode. At this time, the first inlet water temperature minimum allowable temperature min_T2_M2.5 and the second engine oil minimum temperature rise min_T3_M2.5 corresponding to the heating mode corresponding to the second heat engine mode need to be determined according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Tamb. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, based on the ambient temperature Tamb and the engine power Peng_M0, the first inlet water temperature minimum allowable temperature table and the second engine oil minimum temperature rise table corresponding to the non-heating mode are queried to obtain the first inlet water temperature minimum allowable temperature and the second engine oil minimum temperature rise corresponding to the non-heating mode. The first inlet water temperature minimum allowable temperature table is a three-dimensional mapping table pre-set in the second heat engine mode to reflect the mapping relationship between the ambient temperature Tamb, the engine power Peng_M0 and the inlet water temperature minimum temperature rise in the non-heating mode, which can be expressed by Map_T3rise_M2.5. The second engine oil minimum temperature rise table is a three-dimensional mapping table pre-set in the second heat engine mode to reflect the mapping relationship between the ambient temperature Tamb, the engine power Peng_M0 and the engine oil minimum temperature rise in the non-heating mode, which can be expressed by min_T3_M2.5.

[0185] As an example, in step S506, when the engine is in the second heat engine mode and the air conditioning system enters the heating mode, the water temperature of the EMS is maintained or decreased due to the heat exchange of the heater core itself. At this time, the inlet water temperature T2 can be compared with the first inlet water temperature minimum allowable temperature min_T2_M2.5, and the engine oil temperature T3 can be compared with the second engine oil minimum temperature rise value min_T3_M2.5; when the inlet water temperature T2 is less than the first inlet water temperature minimum allowable temperature min_T2_M2.5, or the engine oil temperature T3 is less than the second engine oil minimum temperature rise value min_T3_M2.5, it means that the inlet water temperature T2 is low or the engine oil temperature T3 is low, and the second heat engine mode can be automatically exited, and the engine can be controlled to enter the diversion mode without performing fault diagnosis processing.

[0186] In one embodiment, if Figure 6 As shown, a diagnosis control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnosis control method for the engine cooling system includes:

[0187] S601: when the engine is in the split mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature and inlet water temperature;

[0188] S602: Obtaining a first allowable error threshold corresponding to the split mode according to the engine speed, the engine torque and the ambient temperature;

[0189] S603: Obtain a heat dissipation deviation value according to the engine speed, the engine torque, the ambient temperature, the outlet water temperature, and the inlet water temperature, and obtain a fault detection result according to the heat dissipation deviation value and a first allowable error threshold;

[0190] S604: When the fault detection result is that a fault exists, determine the engine fault level according to the heat dissipation deviation value, and execute a target control strategy corresponding to the engine fault level.

[0191] Among them, step S601 is a specific implementation of step S201, step S602 is a specific implementation of step S202, step S603 is a specific implementation of step S203, and step S604 is a specific implementation of step S204.

[0192] As an example, in step S601, when the engine is in the diversion mode, the EMS needs to obtain measured data such as engine speed EngSpd, engine torque EngTorq, ambient temperature Tamb, outlet water temperature T1 and inlet water temperature T2, so as to perform fault diagnosis based on the above measured data.

[0193] As an example, in step S602, when the engine is in the diversion mode, the EMS needs to determine the first allowable error threshold Q_diff_tres_M3 corresponding to the diversion mode according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Ta_amb, and determine it as the target temperature threshold corresponding to the diversion mode. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, the EMS queries the first allowable error mapping table corresponding to the diversion mode based on the ambient temperature Ta_amb and the engine power Peng_M0, obtains the allowable error value corresponding to the ambient temperature Ta_amb and the engine power Peng_M0 from the first allowable error mapping table, and determines it as the first allowable error threshold Q_diff_tres_M3 corresponding to the diversion mode. The first allowable error mapping table is a three-dimensional mapping table pre-set in the diversion mode to reflect the mapping relationship between the ambient temperature Ta_amb, the engine power Peng_M0 and the allowable error value. The first permissible error threshold Q_diff_tres_M3 herein is a preset error threshold allowed to be reached in the diversion mode.

[0194] As an example, in step S603, the EMS may use a theoretical heat dissipation algorithm to calculate and process input parameters including but not limited to engine speed EngSpd, engine torque EngTorq and ambient temperature Tamb, and calculate the theoretical heat dissipation QCout inferred from the engine operating conditions; and use an actual heat dissipation algorithm to calculate and process input parameters including but not limited to outlet water temperature T1 and inlet water temperature T2, and calculate the actual heat dissipation QRout inferred from the water temperature; finally, based on the theoretical heat dissipation QCout and the actual heat dissipation QRout, calculate the final heat dissipation deviation value Q_diff, specifically using Q_diff = (QRout-QCout) / QCout*100 to calculate the heat dissipation deviation value Q_diff, so as to evaluate whether there is a fault based on the heat dissipation deviation value Q_diff. In this example, the heat dissipation deviation value Q_diff can effectively reflect the difference in heat dissipation calculated from the two dimensions of engine operating conditions and water temperature in the engine.

[0195] In this example, after calculating the heat dissipation deviation value Q_diff, the EMS can compare the heat dissipation deviation value Q_diff with the first allowable error threshold Q_diff_tres_M3 corresponding to the diversion mode, and evaluate whether heat dissipation exists based on the comparison result, so as to evaluate whether the heat dissipation deviation value Q_diff calculated according to different dimensions is within the first allowable error threshold Q_diff_tres_M3, and obtain the fault detection result.

[0196] In one embodiment, in step S603, obtaining a fault detection result according to the heat dissipation deviation value and the first allowable error threshold value includes:

[0197] S6031: If the absolute value of the heat dissipation deviation value is greater than the first allowable error threshold, obtaining a fault detection result indicating that a fault exists;

[0198] S6032: If the absolute value of the heat dissipation deviation value is not greater than the first allowable error threshold, obtaining a fault detection result indicating that no fault exists;

[0199] Since the first allowable error threshold Q_diff_tres_M3 is the error threshold allowed in the shunt mode, which is generally a positive number, and the heat dissipation deviation value Q_diff calculated according to the measured data is calculated by the difference between the theoretical heat dissipation QCout and the actual heat dissipation QRout, the calculated heat dissipation deviation value Q_diff may be a positive number or a negative number. At this time, the absolute value of the heat dissipation deviation value Q_diff can effectively reflect the difference in the heat dissipation calculated in the two dimensions. Therefore, the absolute value of the heat dissipation deviation value Q_diff can be compared with the first allowable error threshold Q_diff_tres_M3; when the absolute value of the heat dissipation deviation value Q_diff is greater than the first allowable error threshold Q_diff_tres_M3 (i.e., Q_diff>

[0200] Q_diff_tres_M3), it can be determined that the difference in heat dissipation calculated based on the two dimensions is large, exceeding the range allowed by the shunt mode. Therefore, a fault detection result indicating that a fault exists can be obtained. Conversely, when the absolute value of the heat dissipation deviation value Q_diff is not greater than the first allowable error threshold Q_diff_tres_M3 (i.e., Q_diff≤Q_diff_tres_M3), it can be determined that the difference in heat dissipation calculated based on the two dimensions is small, does not exceed the range allowed by the shunt mode, and therefore, a fault detection result indicating that a fault does not exist can be obtained.

[0201] As an example, in step S604, when the EMS determines that the fault detection result is a fault, it can further determine the fault risk corresponding to the current moment according to the actual heat dissipation QRout, so as to determine the engine fault level, and execute the target control strategy corresponding to the engine fault level. In this example, since the actual heat dissipation QRout is determined according to the difference between the calculated theoretical heat dissipation QCout and the actual heat dissipation QRout, it may be a positive number or a negative number, which can reflect the size of the theoretical heat dissipation QCout calculated according to the engine working condition and the actual heat dissipation QRout calculated according to the water temperature, so as to determine the specific engine fault level, and execute the corresponding target control strategy, so as to avoid risks and ensure the normal operation of the engine.

[0202] Accordingly, in step S604, the engine fault level is determined according to the heat dissipation deviation value, and a target control strategy corresponding to the engine fault level is executed, including:

[0203] S6041: If the heat dissipation deviation value is a positive number, determining that the engine fault level is the first fault level, and recording the engine fault level;

[0204] S6042: If the heat dissipation deviation value is a negative number, the engine fault level is determined to be the second fault level, and the engine is controlled to enter a normal working mode.

[0205] As an example, in step S6041, when the heat dissipation deviation value Q_diff is a positive number, the EMS can determine that the actual heat dissipation QRout according to the water temperature is greater than the theoretical heat dissipation QCout determined according to the engine operating conditions, and the engine cooling system is rapidly heating up, there is a risk of failure and the severity of the failure is the lowest, so the fault bit Bit_error can be set to M3_T_low, the engine fault level is determined to be the first fault level, and the engine fault level is recorded. In this example, when the engine fault level is the first fault level, the impact of the fault on the engine and the vehicle operation is small and can be ignored. Therefore, only the fault code corresponding to the engine fault level is stored internally, and there is no need to output prompt information to avoid interfering with the user's normal driving.

[0206] As an example, when the heat dissipation deviation value Q_diff is negative, the EMS can determine that the actual heat dissipation QRout according to the water temperature is less than the theoretical heat dissipation QCout determined according to the engine operating conditions. At this time, the cooling system temperature rises rapidly, which does not meet the requirements of the diversion mode. At this time, it can be determined that the engine has a fault but the fault severity is low, so its fault bit Bit_error can be set to M3_T_high, and the engine fault level is determined to be the second fault level. In this example, when the engine fault level is the second fault level, the EMS can record the fault value and not control the instrument to prompt processing, but can try to respond to risks, specifically controlling the engine to enter a normal working mode with better cooling performance.

[0207] In one embodiment, after step S6041, that is, if the heat dissipation deviation value is a positive number, the engine fault level is determined to be the first fault level, and after recording the engine fault level, the diagnosis and control method of the engine cooling system further includes:

[0208] The oil temperature T3 is compared with the first oil temperature threshold. When the oil temperature T3 is less than the first oil temperature threshold, the engine fault level is determined to be the second fault level, the bypass valve is controlled to be closed, and the vehicle driving mode is controlled to enter the sports mode.

[0209] The first oil temperature threshold is a pre-set temperature threshold related to the oil temperature T3 in the diversion mode, and can be represented by T3_tres_M3.

[0210] As an example, when the engine is in the diversion mode and determines that the engine fault level is the first fault level, after recording the engine fault level, the EMS can compare the real-time collected oil temperature T3 with the preset first oil temperature threshold T3_tres_M3; when the oil temperature T3 is less than the first oil temperature threshold T3_tres_M3, it can be determined that the oil temperature T3 does not meet the heat required by the diversion mode. At this time, the engine fault level can be determined to be the second fault level, and the bypass valve can be forcibly closed. Specifically, the second target opening of the bypass valve is set to 0 to close the warm air branch to reduce the risk; and the EMS can also switch the vehicle driving mode to the sports mode, and correct the target idle speed upward to idle_high to improve the engine's work and heat generation capabilities.

[0211] In one embodiment, if Figure 7 As shown, a diagnosis control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnosis control method for the engine cooling system includes:

[0212] S701: When the engine is in a normal working mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature and inlet water temperature;

[0213] S702: Obtaining a second allowable error threshold corresponding to the normal working mode according to the engine speed, the engine torque and the ambient temperature;

[0214] S703: Obtain a heat dissipation deviation value according to the engine speed, the engine torque, the ambient temperature, the outlet water temperature and the inlet water temperature, and obtain a fault detection result according to the heat dissipation deviation value and the second allowable error threshold;

[0215] S704: When the fault detection result is that a fault exists, determine the engine fault level according to the heat dissipation deviation value, and execute a target control strategy corresponding to the engine fault level.

[0216] Among them, step S701 is a specific implementation of step S201, step S702 is a specific implementation of step S202, step S703 is a specific implementation of step S203, and step S704 is a specific implementation of step S204.

[0217] As an example, in step S701, when the engine is in normal operation mode, the EMS needs to obtain measured data such as engine speed EngSpd, engine torque EngTorq, ambient temperature Tamb, outlet water temperature T1 and inlet water temperature T2, so as to perform fault diagnosis based on the above measured data.

[0218] As an example, in step S702, when the engine is in the normal working mode, the EMS needs to determine the second allowable error threshold Q_diff_tres_M4 corresponding to the normal working mode according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Ta_amb, and determine it as the target temperature threshold corresponding to the normal working mode. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, the EMS queries the second allowable error mapping table corresponding to the normal working mode based on the ambient temperature Ta_amb and the engine power Peng_M0, obtains the allowable error value corresponding to the ambient temperature Ta_amb and the engine power Peng_M0 from the second allowable error mapping table, and determines it as the second allowable error threshold Q_diff_tres_M4 corresponding to the normal working mode. The second allowable error mapping table is a three-dimensional mapping table pre-set in the normal working mode to reflect the mapping relationship between the ambient temperature Ta_amb, the engine power Peng_M0 and the allowable error value. The second permissible error threshold Q_diff_tres_M4 herein is a preset error threshold allowed to be reached in the normal working mode.

[0219] As an example, in step S703, the EMS may use a theoretical heat dissipation algorithm to calculate and process input parameters including but not limited to engine speed EngSpd, engine torque EngTorq and ambient temperature Tamb, and calculate the theoretical heat dissipation QCout inferred from the engine operating conditions; and use an actual heat dissipation algorithm to calculate and process input parameters including but not limited to outlet water temperature T1 and inlet water temperature T2, and calculate the actual heat dissipation QRout inferred from the water temperature; finally, based on the theoretical heat dissipation QCout and the actual heat dissipation QRout, calculate the final heat dissipation deviation value Q_diff, specifically using Q_diff = (QRout-QCout) / QCout*100 to calculate the heat dissipation deviation value Q_diff, so as to evaluate whether there is a fault based on the heat dissipation deviation value Q_diff. In this example, the heat dissipation deviation value Q_diff can effectively reflect the difference in heat dissipation calculated from the two dimensions of engine operating conditions and water temperature in the engine.

[0220] In this example, after calculating the heat dissipation deviation value Q_diff, the EMS may compare the heat dissipation deviation value Q_diff with the second allowable error threshold value Q_diff_tres_M4 corresponding to the normal working mode, and evaluate whether heat dissipation exists according to the comparison result.

[0221] In one embodiment, in step S703, obtaining a fault detection result according to the heat dissipation deviation value and the second allowable error threshold value includes:

[0222] S7031: If the absolute value of the heat dissipation deviation value is greater than the second allowable error threshold, obtaining a fault detection result indicating that a fault exists;

[0223] S7032: If the absolute value of the heat dissipation deviation value is not greater than the second allowable error threshold, obtaining a fault detection result indicating that no fault exists;

[0224] Since the second allowable error threshold Q_diff_tres_M4 is the error threshold allowed to be reached in the normal working mode, it is generally a positive number, and the heat dissipation deviation value Q_diff calculated according to the measured data is calculated by the difference between the theoretical heat dissipation QCout and the actual heat dissipation QRout. The calculated heat dissipation deviation value Q_diff may be a positive number or a negative number. At this time, the absolute value of the heat dissipation deviation value Q_diff can effectively reflect the difference in the heat dissipation calculated in the two dimensions. Therefore, the absolute value of the heat dissipation deviation value Q_diff can be compared with the second allowable error threshold Q_diff_tres_M4; when the absolute value of the heat dissipation deviation value Q_diff is greater than the second allowable error threshold Q_diff_tres_M4 (i.e., Q_diff>

[0225] Q_diff_tres_M4), it can be determined that the difference in heat dissipation calculated based on the two dimensions is large, exceeding the range allowed by the normal working mode. Therefore, a fault detection result indicating that a fault exists can be obtained; conversely, when the absolute value of the heat dissipation deviation value Q_diff is not greater than the second allowable error threshold Q_diff_tres_M4 (i.e., Q_diff≤Q_diff_tres_M4), it can be determined that the difference in heat dissipation calculated based on the two dimensions is small, does not exceed the range allowed by the normal working mode, and therefore, a fault detection result indicating that a fault does not exist can be obtained.

[0226] As an example, in step S704, when the EMS determines that the fault detection result is a fault, it can further determine the fault risk corresponding to the current moment according to the actual heat dissipation QRout, so as to determine the engine fault level and execute the target control strategy corresponding to the engine fault level. In this example, since the actual heat dissipation QRout is determined according to the difference between the calculated theoretical heat dissipation QCout and the actual heat dissipation QRout, it may be a positive number or a negative number, which can reflect the size of the theoretical heat dissipation QCout calculated according to the engine working condition and the actual heat dissipation QRout calculated according to the water temperature, so as to determine the specific engine fault level and execute the corresponding target control strategy to avoid risks and ensure the normal operation of the engine.

[0227] Accordingly, in step S704, the engine fault level is determined according to the heat dissipation deviation value, and a target control strategy corresponding to the engine fault level is executed, including:

[0228] S7041: If the heat dissipation deviation value is a positive number, the engine fault level is determined to be the first fault level, and the engine fault level is recorded;

[0229] S7042: If the heat dissipation deviation value is a negative number, the engine fault level is determined to be the third fault level, the control instrument outputs the second fault prompt information, and the engine is controlled to enter the second emergency mode.

[0230] As an example, in step S7041, when the heat dissipation deviation value Q_diff is a positive number, the EMS can determine that the actual heat dissipation QRout according to the water temperature is greater than the theoretical heat dissipation QCout determined according to the engine operating conditions, and the engine cooling system is rapidly heating up, there is a risk of failure and the severity of the failure is the lowest, so the fault bit Bit_error can be set to M3_T_low, the engine fault level is determined to be the first fault level, and the engine fault level is recorded. In this example, when the engine fault level is the first fault level, the impact of the fault on the engine and the vehicle operation is small and can be ignored. Therefore, only the fault code corresponding to the engine fault level is stored internally, and there is no need to output prompt information to avoid interfering with the user's normal driving.

[0231] The second emergency mode refers to an emergency mode when the engine is in a normal working mode.

[0232] As an example, when the heat dissipation deviation value Q_diff is a negative number, the EMS can determine that the actual heat dissipation QRout according to the water temperature is less than the theoretical heat dissipation QCout determined according to the engine operating condition. At this time, the cooling system temperature rises rapidly, which does not meet the requirements of the normal working mode. At this time, it can be determined that the engine has a fault but the fault severity is medium, so its fault bit Bit_error can be set to M3_T_high, and the engine fault level is determined to be the third fault level; and the second fault prompt information can be output, for example, "the engine has an overheating risk" can be output. Remind the driver to drive carefully; and, in order to further avoid risks, emergency risk processing can be performed, specifically, the temperature control module, bypass valve and electronic water pump can be controlled to work, so that the engine enters the second emergency mode, specifically, the third emergency opening p_TMM100_M4 is determined as the first target opening of the temperature control module, and the temperature control module is controlled to work; the fourth emergency opening p_BPV100_M4 is determined as the second target opening of the bypass valve, and the bypass valve is controlled to work; the second emergency speed n_ewp100_M4 is determined as the target speed of the electronic water pump, and the electronic water pump is controlled to work. Among them, the third emergency opening p_TMM100_M4, the fourth emergency opening p_BPV100_M4 and the second emergency speed n_ewp100_M4 depend on the vehicle model, and are values ​​determined after calibration tests of different vehicle models.

[0233] In one embodiment, after step S7041, that is, after determining that the engine fault level is the first fault level and recording the engine fault level, the diagnosis and control method of the engine cooling system further includes:

[0234] S7051: According to the engine oil temperature T3, obtain the engine oil temperature rise rate value T3_rise_spd, compare the engine oil temperature rise rate value T3_rise_spd with the engine oil temperature rise rate limit value T3_rise_tres_M4, and compare the engine oil temperature T3 with the second oil temperature threshold value T3_tres_M4;

[0235] S7052: If the engine oil temperature T3 is less than the second oil temperature threshold value T3_tres_M4, and the engine oil temperature rise rate value T3_rise_spd is less than the engine oil temperature rise rate limit value T3_rise_tres_M4, then compare the outlet water temperature T1 with the third outlet water temperature threshold value, and compare the inlet water temperature T2 with the third inlet water temperature threshold value;

[0236] S7053: If the outlet water temperature T1 is less than the third outlet water temperature threshold, and the inlet water temperature T2 is less than the third inlet water temperature threshold, the engine fault level is determined to be the second fault level, the first target opening of the temperature control module is controlled to be less than the cooling opening threshold, and the vehicle driving mode is controlled to enter the sports mode.

[0237] Among them, the second oil temperature threshold value T3_tres_M4 is a temperature threshold value related to the oil temperature T3 pre-set in the normal working mode, specifically the temperature threshold value when the engine fault level is the first fault level, which can be represented by T3_tres_M4. Generally, T3_tres_M4 is set to be relatively small and is used to evaluate whether the oil temperature T3 is too low. The third outlet water temperature threshold value is a temperature threshold value pre-set in the normal working mode for evaluating the fault severity of the outlet water temperature T1, which can be represented by T1_tres_M4. The third inlet water temperature threshold value is a temperature threshold value pre-set in the normal working mode for evaluating the fault severity of the inlet water temperature T2, which can be represented by T2_tres_M4.

[0238] As an example, in step S7051, when the engine is in normal working mode and the engine fault level is the first fault level, the EMS can calculate the oil temperature rise rate value T3_rise_spd based on the real-time collected oil temperature T1; then, the calculated oil temperature rise rate value T3_rise_spd is compared with the oil temperature rise rate limit T3_rise_tres_M4 corresponding to the normal working mode, and the oil temperature T3 is compared with the pre-set second oil temperature threshold value T3_tres_M4T3_tres_M4, so as to perform subsequent processing according to the comparison result.

[0239] As an example, in step S7052, when the engine oil temperature T3 is less than the second engine oil temperature threshold T3_tres_M4T3_tres_M4, and the engine oil temperature rise rate value T3_rise_spd is less than the engine oil temperature rise rate limit value T3_rise_tres_M4 (i.e., T3 < T3_tres_M4 and

[0240] T3_rise_spd < T3_rise_tres_M4), it can be determined that the severity of the fault existing in the engine is gradually increasing. At this time, it is necessary to compare the real-time collected outlet water temperature T1 with the third outlet water temperature threshold T1_tres_M4, and compare the inlet water temperature T2 with the third inlet water temperature threshold T2_tres_M4, so as to re-determine the severity of the fault according to the comparison results.

[0241] As an example, in step S7053, when the outlet water temperature T1 is less than the third outlet water temperature threshold T1_tres_M4, and the inlet water temperature T2 is less than the third inlet water temperature threshold T2_tres_M4 (i.e., T1 < T1_tres_M4 and T2 < T2_tres_M4), it can be determined that the severity of the fault has risen from the minimum level to a relatively low level. At this time, it can be determined that the engine fault level is the second fault level, and the bypass valve is forcibly closed. Specifically, the first target opening of the temperature control module is less than the forbidden opening radiator opening threshold to prohibit the radiator from opening and participating in the coolant circulation to reduce the risk; and, the EMS can control the vehicle driving mode to switch to the sport mode, and correct the target idle speed upward to idle_high to improve the engine's work and heat generation capacity.

[0242] In one embodiment, after step S7042, that is, after determining that the engine fault level is the third fault level, controlling the instrument to output the second fault prompt information, and controlling the engine to enter the second emergency mode, the diagnostic control method of the engine cooling system further includes:

[0243] S7061: Compare the engine oil temperature T3 with the third engine oil temperature threshold;

[0244] S7062: If the engine oil temperature T3 is less than the third engine oil temperature threshold, determine that the engine fault level is the fourth fault level, and control the engine to enter the speed limit working condition.

[0245] Among them, the third engine oil temperature threshold is a temperature threshold related to the engine oil temperature T3 set in advance in the normal working mode, which can be represented by T3_Hi_tres_M4. T3_Hi_tres_M4 is generally set relatively high to evaluate whether the engine oil temperature T3 reaches a relatively high standard.

[0246] As an example, after the EMS determines that the engine is in the normal operating mode and the engine fault level is the third fault level, controls the instrument to output the second fault prompt message, and controls the engine to enter the second emergency mode, it can compare the real-time collected oil temperature T3 with the pre-set third oil temperature threshold T3_Hi_tres_M4; when the oil temperature T3 is less than the third oil temperature threshold T3_Hi_tres_M4 (i.e., T3 < T3_Hi_tres_M4), it can be determined that the severity of the fault has increased from medium to large. At this time, it can be determined that the engine fault level is the fourth fault level, and the engine is controlled to enter the speed limit condition to appropriately limit the engine power and avoid further exacerbating the fault risk.

[0247] In one embodiment, as Figure 8 shown, a diagnostic control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnostic control method for the engine cooling system includes:

[0248] S801: When the engine is in the overheat mode, obtain the measured data, where the measured data includes the outlet water temperature, the inlet water temperature, and the oil temperature;

[0249] S802: Obtain the pre-set first water temperature safety threshold, first oil temperature safety threshold, and first temperature difference safety threshold corresponding to the overheat mode;

[0250] S803: According to the outlet water temperature and the inlet water temperature, obtain the measured temperature difference value; according to the comparison result between the outlet water temperature and the first water temperature safety threshold, the comparison result between the oil temperature threshold and the first oil temperature safety threshold, and the comparison result between the measured temperature difference value and the first temperature difference safety threshold, obtain the fault detection result;

[0251] S804: When the fault detection result is that there is a fault, determine the engine fault level according to the outlet water temperature, the inlet water temperature, and the oil temperature, and execute the target control strategy corresponding to the engine fault level.

[0252] Among them, step S801 is a specific implementation manner of step S201, step S802 is a specific implementation manner of step S202, step S803 is a specific implementation manner of step S203, and step S804 is a specific implementation manner of step S204.

[0253] As an example, in step S801, when the engine is in the overheat mode, the EMS can obtain the measured data such as the outlet water temperature T1, the inlet water temperature T2, and the oil temperature T3, so as to perform fault diagnosis based on the above measured data subsequently.

[0254] As an example, in step S802, the EMS may obtain the first water temperature safety threshold T1_tres_M5, the first oil temperature safety threshold T3_tres_M5 and the first temperature difference safety threshold T_delta_tres_M5 corresponding to the pre-set overheating mode from the memory connected thereto. Among them, the first water temperature safety threshold T1_tres_M5 is the first safety threshold pre-set in the overheating mode for evaluating whether the outlet water temperature T1 has an overheating risk. The first oil temperature safety threshold T3_tres_M5 is the first safety threshold pre-set in the overheating mode for evaluating whether the engine oil temperature T3 has an overheating risk. The first temperature difference safety threshold T_delta_tres_M5 is the first temperature difference threshold pre-set in the overheating mode for evaluating whether the measured temperature difference value has an overheating risk.

[0255] As an example, in step S803, when the EMS controls the engine to enter the overheating mode, it can compare the real-time collected outlet water temperature T1 with the preset first water temperature safety threshold T1_tres_M5; compare the oil temperature T3 with the first oil temperature safety threshold T3_tres_M5; and calculate the engine's actual temperature difference T_delta based on the engine's outlet water temperature T1 and inlet water temperature T2. In this example, T_delta=T1-T2, and then compare the actual temperature difference T_delta with the first temperature difference safety threshold T_delta_tres_M5, so as to determine whether the engine has a fault in the overheating mode based on the three comparison results.

[0256] In one embodiment, step S803, i.e., obtaining a fault detection result according to a comparison result between the outlet water temperature T1 and the first water temperature safety threshold, a comparison result between the engine oil temperature threshold and the first oil temperature safety threshold, and a comparison result between the measured temperature difference and the first temperature difference safety threshold, includes:

[0257] S8031: If the outlet water temperature T1 is greater than or equal to the first water temperature safety threshold, the engine oil temperature T3 is greater than or equal to the first oil temperature safety threshold, or the measured temperature difference is greater than or equal to the first temperature difference safety threshold, then a fault detection result indicating a fault exists is obtained;

[0258] S8032: If the outlet water temperature T1 is less than the first water temperature safety threshold, the engine oil temperature T3 is less than the first oil temperature safety threshold, and the measured temperature difference is less than the first temperature difference safety threshold, a fault detection result indicating that no fault exists is obtained.

[0259] As an example, in step S8031, when the outlet water temperature T1 of the engine is greater than or equal to the first water temperature safety threshold T1_tres_M5 (T1≥T1_tres_M5), the oil temperature T3 is greater than or equal to the first oil temperature safety threshold T3_tres_M5 (T3≥T3_tres_M5), or the measured temperature difference value T_delta is greater than or equal to the first temperature difference safety threshold T_delta_tres_M5 (T_delta≥T_delta_tres_M5), etc., it can be determined that there is an overheating risk in any one of the outlet water temperature T1, inlet water temperature T2, and oil temperature T3 of the engine, and a fault detection result indicating a fault is obtained. Comparisons are made to determine whether there is a fault in the engine in the overheating mode based on the three comparison results.

[0260] As an example, in step S8032, when the outlet water temperature T1 of the engine is less than the first water temperature safety threshold T1_tres_M5 (T1<T1_tres_M5), the oil temperature T3 is less than the first oil temperature safety threshold T3_tres_M5 (T3<T3_tres_M5), and the measured temperature difference value T_delta is less than the first temperature difference safety threshold T_delta_tres_M5 (T_delta<T_delta_tres_M5), etc., it can be determined that there is no overheating risk in the outlet water temperature T1, inlet water temperature T2, and oil temperature T3 of the engine, and a fault detection result indicating no fault is obtained.

[0261] As an example, in step S804, when the engine is in the overheating mode and the fault detection result indicates a fault, it is necessary to further evaluate the severity of the fault based on the real-time obtained outlet water temperature T1, inlet water temperature T2, and oil temperature T3 to determine the engine fault level, and then execute the target control strategy corresponding to the engine fault level to ensure the safety of the engine.

[0262] In one embodiment, the target temperature thresholds corresponding to the current mode further include the second water temperature safety threshold, the second oil temperature safety threshold, and the second temperature difference safety threshold corresponding to the overheating mode. The first water temperature safety threshold is less than the second water temperature safety threshold, the first oil temperature safety threshold is less than the second oil temperature safety threshold, and the first temperature difference safety threshold is less than the second temperature difference safety threshold;

[0263] In step S804, determining the engine fault level based on the outlet water temperature T1, inlet water temperature T2, and oil temperature T3 and executing the target control strategy corresponding to the engine fault level includes:

[0264] S8041: If the outlet water temperature T1 is between the first water temperature safety threshold and the second water temperature safety threshold, the oil temperature T3 is between the first oil temperature safety threshold and the second oil temperature safety threshold, or the measured temperature difference value is between the first temperature difference safety threshold and the second temperature difference safety threshold, then determine that the engine fault level is the fourth fault level, and control the engine to enter the speed limit condition;

[0265] S8042: If the outlet water temperature T1 is greater than or equal to the second water temperature safety threshold, the oil temperature T3 is greater than or equal to the second oil temperature safety threshold, or the measured temperature difference value is greater than or equal to the second temperature difference safety threshold, then determine that the engine fault level is the fifth fault level, and control the engine to enter the idle condition.

[0266] Among them, the second water temperature safety threshold T1_tres2_M5 is the second safety threshold preset in the overheat mode for evaluating whether there is an overheat risk in the outlet water temperature T1, and the first water temperature safety threshold is less than the second water temperature safety threshold. The second oil temperature safety threshold T3_tres2_M5 is the second safety threshold preset in the overheat mode for evaluating whether there is an overheat risk in the oil temperature T3, and the first oil temperature safety threshold is less than the second oil temperature safety threshold. The second temperature difference safety threshold T_delta_tres2_M5 is the second temperature threshold preset in the overheat mode for evaluating whether there is an overheat risk in the measured temperature difference value, and the first temperature difference safety threshold is less than the second temperature difference safety threshold.

[0267] As an example, when the engine is in the overheat mode and the fault detection result is that there is a fault, the EMS can compare the real-time collected outlet water temperature T1 with the preset first water temperature safety threshold T1_tres_M5 and the second water temperature safety threshold T1_tres2_M5; if the outlet water temperature T1 is between the first water temperature safety threshold T1_tres_M5 and the second water temperature safety threshold T1_tres2_M5 (that is, T1_tres_M5 ≤ T1 < T1_tres2_M5), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most serious level, it can be determined that the engine fault level is the fourth fault level, and the engine can be controlled to enter the speed limit condition to appropriately limit the engine power and avoid further aggravating the fault risk; if the outlet water temperature T1 is greater than or equal to the second water temperature safety threshold T1_tres2_M5 (that is, T1 ≥ T1_tres2_M5), it is determined that the engine has an overheat risk and the overheat risk has reached the most serious level, it can be determined that the engine fault level is the fifth fault level, and the engine can be controlled to enter the idle condition to ensure operation safety.

[0268] As an example, when the engine is in the overheat mode and the fault detection result indicates a fault, the EMS can compare the real-time collected engine oil temperature T3 with the pre-set first oil temperature safety threshold T3_tres_M5 and the second oil temperature safety threshold T3_tres2_M5; if the engine oil temperature T3 is between the first oil temperature safety threshold T3_tres_M5 and the second oil temperature safety threshold T3_tres2_M5 (i.e., T3_tres_M5 ≤ T3 < T3_tres2_M5), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most severe level. It can be determined that the engine fault level is the fourth fault level, and the engine can be controlled to enter the speed limit working condition to appropriately limit the engine power and avoid further aggravating the fault risk; if the engine oil temperature T3 is greater than or equal to the second oil temperature safety threshold T3_tres2_M5 (i.e., T3 ≥ T3_tres2_M5), it is determined that the engine has an overheat risk and the overheat risk has reached the most severe level. It can be determined that the engine fault level is the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0269] As an example, when the engine is in the overheat mode and the fault detection result indicates a fault, the EMS can compare the measured temperature difference value T_delta with the pre-set first temperature difference safety threshold T_delta_tres_M5 and the second temperature difference safety threshold T_delta_tres2_M5; if the measured temperature difference value T_delta is between the first temperature difference safety threshold T_delta_tres_M5 and the second temperature difference safety threshold T_delta_tres2_M5 (i.e., T_delta_tres_M5 ≤ T_delta < T_delta_tres2_M5), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most severe level. It can be determined that the engine fault level is the fourth fault level, and the engine can be controlled to enter the speed limit working condition to appropriately limit the engine power and avoid further aggravating the fault risk; if the measured temperature difference value T_delta is greater than or equal to the second temperature difference safety threshold T_delta_tres2_M5 (i.e., T_delta ≥ T_delta_tres2_M5), it is determined that the engine has an overheat risk and the overheat risk has reached the most severe level. It can be determined that the engine fault level is the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0270] In one embodiment, as Fig. 9 shown, a diagnostic control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnostic control method for the engine cooling system includes:

[0271] S901: When the engine is in the heat preservation and waste heat utilization mode, the measured data is obtained, and the measured data includes engine speed, engine torque, ambient temperature, inlet water temperature, oil temperature and air conditioning demand;

[0272] S902: If the air conditioning demand is no heating demand, obtaining a maximum water temperature drop value and a maximum oil temperature drop value corresponding to the non-heating mode according to the engine speed, the engine torque and the ambient temperature;

[0273] S903: Obtaining a fault detection result according to the inlet water temperature, the engine oil temperature, the maximum water temperature drop value, and the maximum oil temperature drop value;

[0274] S904: When the fault detection result is that a fault exists, determine that the engine fault level is a second fault level, and control the engine to enter an idle state.

[0275] Among them, step S901 is a specific implementation of step S201, step S902 is a specific implementation of step S202, step S903 is a specific implementation of step S203, and step S904 is a specific implementation of step S204.

[0276] As an example, in step S901, when the engine is in the heat preservation and waste heat utilization mode, the EMS can obtain measured data such as engine speed, engine torque, ambient temperature, inlet water temperature T2, oil temperature T3 and air conditioning demand, so as to perform fault diagnosis based on the above measured data.

[0277] As an example, in step S902, when the engine is in the heat preservation and waste heat utilization mode and the air conditioning demand is no heating demand, the EMS needs to control the air conditioning system to enter the non-heating mode. At this time, according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Tamb, the maximum water temperature drop value max_T2downM6_spd and the maximum oil temperature drop value max_T3downM6_spd corresponding to the non-heating mode in the heat preservation and waste heat utilization mode are determined. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, based on the ambient temperature Tamb and the engine power Peng_M0, the maximum water temperature drop mapping table and the maximum oil temperature drop mapping table corresponding to the non-heating mode in the heat preservation and waste heat utilization mode are queried to obtain the maximum water temperature drop value max_T2downM6_spd and the maximum oil temperature drop value max_T3downM6_spd. Among them, the maximum water temperature drop mapping table is a three-dimensional mapping table that reflects the mapping relationship between the ambient temperature T_amb, the engine power Peng_M0 and the maximum water temperature drop value max_T2downM6_spd, which is pre-configured for the non-heating mode in the heat preservation and waste heat utilization mode, and can be represented by Map_T2down_M6. The maximum oil temperature drop mapping table is a three-dimensional mapping table that reflects the mapping relationship between the ambient temperature T_amb, the engine power Peng_M0 and the maximum oil temperature drop value max_T3downM6_spd, which is pre-configured for the non-heating mode in the heat preservation and waste heat utilization mode, and can be represented by Map_T2down_M6.

[0278] As an example, in step S903, when the engine is in the heat preservation and waste heat utilization mode, the EMS can calculate the inlet water temperature change value and the measured oil change value within a specific time period based on the inlet water temperature T2 and oil temperature T3 collected in real time, so as to compare the inlet water temperature change value with the maximum water temperature drop value, and compare the measured oil change value with the maximum oil temperature drop value. Based on the comparison result, it is determined whether there is a fault in the non-heating mode of the engine in the heat preservation and waste heat utilization mode, and the fault detection result is obtained.

[0279] In one embodiment, step S903, i.e., obtaining a fault detection result according to the inlet water temperature T2, the engine oil temperature T3, the maximum water temperature drop value, and the maximum engine oil temperature drop value, includes:

[0280] S9031: Obtain an inlet water temperature change value and a measured oil change value according to all inlet water temperatures T2 and all oil temperatures T3 within the cycle time;

[0281] S9032: If the absolute value of the inlet water temperature change is greater than the maximum water temperature drop, or the absolute value of the measured engine oil change is greater than the maximum engine oil temperature drop, then update the fourth abnormality number;

[0282] S9033: If the fourth abnormal number is greater than the fourth number threshold, a fault detection result indicating a fault exists is obtained.

[0283] S9034: If the absolute value of the inlet water temperature change is not greater than the maximum water temperature drop and the absolute value of the measured oil change is not greater than the maximum oil temperature drop, or the fourth abnormal number is not greater than the fourth number threshold, a fault detection result indicating that no fault exists is obtained.

[0284] The fourth abnormal number refers to the abnormal number counted in the heat preservation and waste heat utilization mode, which can be represented by abn_M6. The fourth number threshold is a preset threshold for evaluating whether the third abnormal number reaches the fault standard, which can be represented by abn_tres_M6.

[0285] In this example, in step S9031, the EMS can divide the values ​​in the inlet temperature array T2_M[dim1] formed by all the inlet water temperatures T2 collected within the cycle time t_Cal into two segments, namely, T2_M[0~pro] and T2_M[pro+1,dim1-1]; then, the average values ​​of the values ​​of the two segments are calculated, and they are determined as T2_M_pre=ave(T2_M[0~pro]) and T2_M_pro=ave(T2_M[pro+1,dim1-1]); finally, according to the average values ​​of the two segments, the inlet water temperature change value T2_diff_M corresponding to the cycle time is calculated, that is, T2_diff_M=

[0286] T2_M_pro-T2_M_pre. Accordingly, EMS can divide the values ​​in the oil temperature array T3_M[dim1] formed by all the oil temperatures T3 collected within the cycle time t_Cal into two segments, namely T3_M[0~pro] and T3_M[pro+1,dim1-1]; then, the average values ​​of the two segments are calculated, respectively, and determined as T3_M_pre=ave(T3_M[0~pro]), T3_M_pro=ave(T3_M[pro+1,dim1-1]); finally, according to the average values ​​of the two segments, the measured oil change value T3_diff_M corresponding to the cycle time is calculated, that is, T3_diff_M=

[0287] T3_M_pro-T3_M_pre.

[0288] As an example, in step S9032, when the EMS is in the insulation and waste heat utilization mode, the engine's inlet water temperature T2 will decrease, and the oil temperature T3 will also decrease. Referring to the inlet water temperature change value T2_diff_M and the measured oil change value T3_diff_M determined in the previous step, both are negative numbers, but their absolute values ​​reflect the temperature reduction rate. Therefore, the absolute value of the inlet water temperature change value T2_diff_M can be compared with the maximum water temperature drop value max_T2downM6_spd, and the absolute value of the measured oil change value T3_diff_M can be compared with the maximum oil temperature drop value max_T3downM6_spd, so as to determine whether the engine has an abnormality based on the comparison results. When the absolute value of the inlet water temperature change value T2_diff_M is greater than the maximum water temperature drop value max_T2downM6_spd, and the absolute value of the measured engine oil change value T3_diff_M is greater than the maximum oil temperature drop value max_T3downM6_spd, EMS can determine that the engine temperature drop rate is uncontrollable and there is an abnormality in the cooling system. At this time, the fourth abnormal number abn_M6 needs to be updated, that is, abn_M6=abn_M6+1; then, the updated fourth abnormal number abn_M6 is compared with the pre-set fourth number threshold value to determine whether there is an engine fault based on the comparison result.

[0289] As an example, in step S9033, when the fourth abnormal number abn_M6 is greater than the fourth number threshold abn_tres_M6, the EMS can determine that the engine has detected abnormalities a large number of times, can determine that the engine has a fault, and obtain a fault detection result indicating the presence of a fault.

[0290] As an example, in step S9034, when the absolute value of the inlet water temperature change value T2_diff_M is less than or equal to the maximum water temperature drop value max_T2downM6_spd, and the absolute value of the measured oil change value T3_diff_M is less than or equal to the maximum oil temperature drop value max_T3downM6_spd, the EMS can determine that the engine temperature drop speed is controllable, the cooling system works normally, and the engine has no abnormality, so the fault detection result of no fault can be obtained. Accordingly, when the fourth abnormal number abn_M6 is not greater than the fourth number threshold abn_tres_M6, the EMS can determine that the number of abnormalities detected by the engine is small and does not meet the standard for being identified as a fault, and obtain the fault detection result of no fault.

[0291] As an example, in step S904, when the EMS is in the heat preservation and waste heat utilization mode, if the fault detection result obtained is that a fault exists, since the overall engine fault severity in the heat preservation and waste heat utilization mode is relatively small, its fault bit Bit_error=M2_Trise can be set to determine the engine fault level as the second fault level, and the engine can be controlled to idle condition to implement risk control processing to achieve the purpose of risk avoidance.

[0292] As an example, when the engine is in the insulation and waste heat utilization mode, the air-conditioning demand it receives is a heating demand. When the air-conditioning system is controlled to enter the heating mode, since the heater core itself has heat exchange, no diagnosis or processing is performed.

[0293] In one embodiment, if Fig.10 As shown, a diagnosis control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnosis control method for the engine cooling system includes:

[0294] S1001: when the engine is in a start-stop operation mode, obtaining measured data, the measured data including outlet water temperature, inlet water temperature and oil temperature;

[0295] S1002: Obtaining a third water temperature safety threshold, a third oil temperature safety threshold, and a third temperature difference safety threshold corresponding to a preset start-stop post-operation mode;

[0296] S1003: Obtaining a measured temperature difference value according to the outlet water temperature and the inlet water temperature; obtaining a fault detection result according to a comparison result of the outlet water temperature with a third water temperature safety threshold, a comparison result of the engine oil temperature threshold with a third oil temperature safety threshold, and a comparison result of the measured temperature difference value with the third temperature difference safety threshold;

[0297] S1004: When the fault detection result is that a fault exists, determine the engine fault level according to the engine speed, and execute a target control strategy corresponding to the engine fault level.

[0298] Among them, step S1001 is a specific implementation of step S201, step S1002 is a specific implementation of step S202, step S1003 is a specific implementation of step S203, and step S1004 is a specific implementation of step S204.

[0299] As an example, in step S1001, when the engine is in the post-start / stop operation mode, the EMS can obtain measured data such as the outlet water temperature T1, the inlet water temperature T2 and the oil temperature T3, so as to perform fault diagnosis based on the measured data later.

[0300] As an example, in step S1002, the EMS may obtain the third water temperature safety threshold T1_tres_M7, the third oil temperature safety threshold T3_tres_M7 and the third temperature difference safety threshold T_delta_tres_M7 corresponding to the pre-set post-start and stop operation mode from the memory connected thereto. Among them, the third water temperature safety threshold T1_tres_M7 is the first safety threshold pre-set in the post-start and stop operation mode for evaluating whether the outlet water temperature T1 has an overheating risk. The third oil temperature safety threshold T3_tres_M7 is the first safety threshold pre-set in the post-start and stop operation mode for evaluating whether the engine oil temperature T3 has an overheating risk. The third temperature difference safety threshold T_delta_tres_M7 is the first temperature difference threshold pre-set in the post-start and stop operation mode for evaluating whether the measured temperature difference value has an overheating risk.

[0301] As an example, in step S1003, when the EMS controls the engine to enter the post-start-stop operation mode, the real-time collected outlet water temperature T1 can be compared with the preset third water temperature safety threshold T1_tres_M7; the oil temperature T3 can be compared with the third oil temperature safety threshold T3_tres_M7; and the engine's measured temperature difference T_delta can be calculated based on the engine's outlet water temperature T1 and inlet water temperature T2. In this example, T_delta=T1-T2, and then the measured temperature difference T_delta can be compared with the third temperature difference safety threshold T_delta_tres_M7, so as to determine whether the engine has a fault in the post-start-stop operation mode based on the three comparison results.

[0302] In one embodiment, step S1003, i.e., obtaining a fault detection result according to a comparison result between the outlet water temperature T1 and the third water temperature safety threshold, a comparison result between the engine oil temperature threshold and the third oil temperature safety threshold, and a comparison result between the measured temperature difference and the third temperature difference safety threshold, includes:

[0303] If the outlet water temperature T1 is greater than or equal to the third water temperature safety threshold, the engine oil temperature T3 is greater than or equal to the third oil temperature safety threshold, or the measured temperature difference is greater than or equal to the third temperature difference safety threshold, a fault detection result indicating a fault exists is obtained;

[0304] If the outlet water temperature T1 is less than the third water temperature safety threshold, the engine oil temperature T3 is less than the third oil temperature safety threshold, and the measured temperature difference is less than the third temperature difference safety threshold, a fault detection result indicating that no fault exists is obtained.

[0305] As an example, in step S10031, when the outlet water temperature T1 of the engine management system (EMS) is greater than or equal to the third water temperature safety threshold T1_tres_M7 (T1≥T1_tres_M7), the oil temperature T3 is greater than or equal to the third oil temperature safety threshold T3_tres_M7 (T3≥T3_tres_M7), or the measured temperature difference value T_delta is greater than or equal to the third temperature difference safety threshold T_delta_tres_M7 (T_delta≥T_delta_tres_M7), etc., it can be determined that any one of the outlet water temperature T1, inlet water temperature T2, and oil temperature T3 of the engine has an overheating risk, and a fault detection result indicating a fault is obtained. Comparisons are made to determine whether there is a fault in the engine during the start-stop and running mode based on the three comparison results.

[0306] As an example, in step S10032, when the outlet water temperature T1 of the EMS is less than the third water temperature safety threshold T1_tres_M7 (T1<T1_tres_M7), the oil temperature T3 is less than the third oil temperature safety threshold T3_tres_M7 (T3<T3_tres_M7), and the measured temperature difference value T_delta is less than the third temperature difference safety threshold T_delta_tres_M7 (T_delta<T_delta_tres_M7), etc., it can be determined that none of the outlet water temperature T1, inlet water temperature T2, and oil temperature T3 of the engine has an overheating risk, and a fault detection result indicating no fault is obtained.

[0307] As an example, in step S1004, when the engine is in the start-stop and running mode and the fault detection result indicates a fault, the EMS needs to further evaluate whether the engine restarts based on the engine speed obtained in real time, and then evaluate the severity of the fault to determine the engine fault level, and then execute the target control strategy corresponding to the engine fault level to ensure the safety of the engine.

[0308] In one embodiment, the target temperature thresholds corresponding to the current mode further include the fourth water temperature safety threshold, the fourth oil temperature safety threshold, and the fourth temperature difference safety threshold corresponding to the start-stop and running mode. The third water temperature safety threshold is less than the fourth water temperature safety threshold, the third oil temperature safety threshold is less than the fourth oil temperature safety threshold, and the third temperature difference safety threshold is less than the fourth temperature difference safety threshold;

[0309] In step S1004, that is, based on the engine speed, the engine fault level is determined, and the target control strategy corresponding to the engine fault level is executed, including:

[0310] S10041: If the engine speed is 0, it is determined that the engine fault level is the first fault level, and the engine fault level is recorded;

[0311] S10042: If the engine speed is not 0, and the outlet water temperature T1 is between the third water temperature safety threshold and the fourth water temperature safety threshold, the engine oil temperature T3 is between the third oil temperature safety threshold and the fourth oil temperature safety threshold, or the measured temperature difference is between the third temperature difference safety threshold and the fourth temperature difference safety threshold, then the engine fault level is determined to be the fourth fault level, and the engine is controlled to enter the speed limit condition;

[0312] S10043: If the engine speed is not 0, and the outlet water temperature T1 is greater than or equal to the fourth water temperature safety threshold, the oil temperature T3 is greater than or equal to the fourth oil temperature safety threshold, or the measured temperature difference is greater than or equal to the fourth temperature difference safety threshold, then the engine fault level is determined to be the fifth fault level, and the engine is controlled to enter the idle condition.

[0313] Among them, the fourth water temperature safety threshold T1_tres2_M7 is the second safety threshold pre-set in the post-start and stop operation mode for evaluating whether the outlet water temperature T1 has an overheating risk, and the third water temperature safety threshold is less than the fourth water temperature safety threshold. The fourth oil temperature safety threshold T3_tres2_M7 is the second safety threshold pre-set in the post-start and stop operation mode for evaluating whether the oil temperature T3 has an overheating risk, and the third oil temperature safety threshold is less than the fourth oil temperature safety threshold. The fourth temperature difference safety threshold T_delta_tres2_M7 is the second temperature threshold pre-set in the post-start and stop operation mode for evaluating whether the measured temperature difference has an overheating risk, and the third temperature difference safety threshold is less than the fourth temperature difference safety threshold.

[0314] As an example, in step S10041, when the engine is in the post-start / stop operation mode and the fault detection result is a fault, the EMS can obtain the real-time collected engine speed EngSpd. When the engine speed EngSpd is 0, it can be determined that the engine has not been restarted. At this time, although there is an overheating risk, the severity of the fault is small. The fault bit Bit_error can be set to M0_leakage, and the engine fault level is determined to be the first fault level, and the engine fault level is recorded. In this example, when the engine fault level is the first fault level, the impact of the fault on the engine and the vehicle operation is small and can be ignored. Therefore, only the fault code corresponding to the engine fault level is internally stored, and there is no need to output prompt information to avoid interfering with the user's normal driving.

[0315] As an example, when the EMS is in the post - start - stop operation mode of the engine and the fault detection result indicates a fault, it can obtain the real - time collected engine speed EngSpd. When the engine speed EngSpd is not 0, it can be determined that the engine has restarted. At this time, the engine overheat risk is relatively serious. The real - time collected outlet water temperature T1 can be compared with the pre - set third water temperature safety threshold T1_tres_M7 and the fourth water temperature safety threshold T1_tres2_M7. If the outlet water temperature T1 is between the third water temperature safety threshold T1_tres_M7 and the fourth water temperature safety threshold T1_tres2_M7 (i.e., T1_tres_M7 ≤ T1 < T1_tres2_M7), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most serious level. The engine fault level can be determined as the fourth fault level, and the engine can be controlled to enter the speed - limiting working condition to appropriately limit the engine power and avoid further exacerbating the fault risk. If the outlet water temperature T1 is greater than or equal to the fourth water temperature safety threshold T1_tres2_M7 (i.e., T1 ≥ T1_tres2_M7), it is determined that the engine has an overheat risk and the overheat risk has reached the most serious level. The engine fault level can be determined as the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0316] As an example, when the EMS is in the post - start - stop operation mode of the engine and the fault detection result indicates a fault, it can obtain the real - time collected engine speed EngSpd. When the engine speed EngSpd is not 0, it can be determined that the engine has restarted. At this time, the engine overheat risk is relatively serious. The real - time collected oil temperature T3 can be compared with the pre - set third oil temperature safety threshold T3_tres_M7 and the fourth oil temperature safety threshold T3_tres2_M7. If the oil temperature T3 is between the third oil temperature safety threshold T3_tres_M7 and the fourth oil temperature safety threshold T3_tres2_M7 (i.e., T3_tres_M7 ≤ T3 < T3_tres2_M7), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most serious level. The engine fault level can be determined as the fourth fault level, and the engine can be controlled to enter the speed - limiting working condition to appropriately limit the engine power and avoid further exacerbating the fault risk. If the oil temperature T3 is greater than or equal to the fourth oil temperature safety threshold T3_tres2_M7 (i.e., T3 ≥ T3_tres2_M7), it is determined that the engine has an overheat risk and the overheat risk has reached the most serious level. The engine fault level can be determined as the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0317] As an example, when the engine is in the post - start - stop operation mode and the fault detection result indicates a fault, the EMS can obtain the real - time collected engine speed EngSpd. When the engine speed EngSpd is not 0, it can be determined that the engine restarts. At this time, the risk of engine overheating is relatively serious. The measured temperature difference value T_delta can be compared with the pre - set third temperature difference safety threshold T_delta_tres_M7 and the fourth temperature difference safety threshold T_delta_tres2_M7. If the measured temperature difference value T_delta is between the third temperature difference safety threshold T_delta_tres_M7 and the fourth temperature difference safety threshold T_delta_tres2_M7 (i.e., T_delta_tres_M7 ≤ T_delta < T_delta_tres2_M7), it can be determined that the engine has an overheating risk, and the overheating risk has not reached the most serious level. It can be determined that the engine fault level is the fourth fault level, and the engine can be controlled to enter the speed - limiting working condition to appropriately limit the engine power and avoid further exacerbating the fault risk. If the measured temperature difference value T_delta is greater than or equal to the fourth temperature difference safety threshold T_delta_tres2_M7 (i.e., T_delta ≥ T_delta_tres2_M7), it is determined that the engine has an overheating risk and the overheating risk reaches the most serious level. It can be determined that the engine fault level is the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0318] In one embodiment, as Fig.11 shown, a diagnostic control method for an engine cooling system is provided, which can be applied in an engine controller. The diagnostic control method for the engine cooling system includes:

[0319] S1101: When the engine is in the post - hybrid - overheating operation mode, obtain the measured data, where the measured data includes the outlet water temperature, the inlet water temperature, and the oil temperature;

[0320] S1102: Obtain the pre - set fifth water temperature safety threshold, fifth oil temperature safety threshold, and fifth temperature difference safety threshold corresponding to the post - hybrid - overheating operation mode;

[0321] S1103: According to the comparison result between the outlet water temperature and the fifth water temperature safety threshold, the comparison result between the oil temperature threshold and the fifth oil temperature safety threshold, based on the outlet water temperature and the inlet water temperature, obtain the measured temperature difference value, and according to the comparison result between the measured temperature difference value and the fifth temperature difference safety threshold, obtain the fault detection result;

[0322] S1104: When the fault detection result indicates a fault, determine the engine fault level according to the outlet water temperature, the inlet water temperature, and the oil temperature, and execute the target control strategy corresponding to the engine fault level.

[0323] Among them, step S1101 is a specific implementation of step S201, step S1102 is a specific implementation of step S202, step S1103 is a specific implementation of step S203, and step S1104 is a specific implementation of step S204.

[0324] As an example, in step S1101, when the engine is in the hybrid overheating post-operation mode, the EMS can obtain measured data such as the outlet water temperature T1, the inlet water temperature T2 and the oil temperature T3, so as to perform fault diagnosis based on the above measured data.

[0325] As an example, in step S1102, the EMS may obtain the fifth water temperature safety threshold T1_tres_M8, the fifth oil temperature safety threshold T3_tres_M8 and the fifth temperature difference safety threshold T_delta_tres_M8 corresponding to the pre-set hybrid overheating post-operation mode from the memory connected thereto. Among them, the fifth water temperature safety threshold T1_tres_M8 is the first safety threshold pre-set in the hybrid overheating post-operation mode for evaluating whether the outlet water temperature T1 has an overheating risk. The fifth oil temperature safety threshold T3_tres_M8 is the first safety threshold pre-set in the hybrid overheating post-operation mode for evaluating whether the engine oil temperature T3 has an overheating risk. The fifth temperature difference safety threshold T_delta_tres_M8 is the first temperature difference threshold pre-set in the hybrid overheating post-operation mode for evaluating whether the measured temperature difference value has an overheating risk.

[0326] As an example, in step S1103, when the EMS controls the engine to enter the hybrid overheating post-operation mode, the real-time collected outlet water temperature T1 may be compared with the preset fifth water temperature safety threshold T1_tres_M8; the oil temperature T3 may be compared with the fifth oil temperature safety threshold T3_tres_M8; and the measured temperature difference T_delta of the engine may be calculated based on the outlet water temperature T1 and the inlet water temperature T2 of the engine. In this example, T_delta=T1-T2. Then, the measured temperature difference T_delta may be compared with the fifth temperature difference safety threshold T_delta_tres_M8, so as to determine whether the engine has a fault in the hybrid overheating post-operation mode based on the three comparison results.

[0327] In one embodiment, step S1103, i.e., obtaining a measured temperature difference value according to the outlet water temperature T1 and the inlet water temperature T2 based on the comparison result between the outlet water temperature T1 and the fifth water temperature safety threshold, and the comparison result between the engine oil temperature threshold and the fifth oil temperature safety threshold, and obtaining a fault detection result according to the comparison result between the measured temperature difference value and the fifth temperature difference safety threshold, includes:

[0328] S11031: If the outlet water temperature T1 is greater than or equal to the fifth water temperature safety threshold, the engine oil temperature T3 is greater than or equal to the fifth engine oil temperature safety threshold, or the measured temperature difference value is greater than or equal to the fifth temperature difference safety threshold, then obtain the fault detection result indicating a fault.

[0329] S11032: If the outlet water temperature T1 is less than the fifth water temperature safety threshold, the engine oil temperature T3 is less than the fifth engine oil temperature safety threshold, and the measured temperature difference value is less than the fifth temperature difference safety threshold, then obtain the fault detection result indicating no fault.

[0330] As an example, in step S11031, when the EMS determines that the outlet water temperature T1 is greater than or equal to the fifth water temperature safety threshold T1_tres_M8 (T1≥T1_tres_M8), the engine oil temperature T3 is greater than or equal to the fifth engine oil temperature safety threshold T3_tres_M8 (T3≥T3_tres_M8), or the measured temperature difference value T_delta is greater than or equal to the fifth temperature difference safety threshold T_delta_tres_M8 (T_delta≥T_delta_tres_M8), it can determine that there is an overheating risk in any one of the outlet water temperature T1, inlet water temperature T2, and engine oil temperature T3 of the engine, and obtain the fault detection result indicating a fault. Compare them to determine whether there is a fault in the engine under the hybrid overheating operation mode based on the three comparison results.

[0331] As an example, in step S11032, when the EMS determines that the outlet water temperature T1 is less than the fifth water temperature safety threshold T1_tres_M8 (T1<T1_tres_M8), the engine oil temperature T3 is less than the fifth engine oil temperature safety threshold T3_tres_M8 (T3<T3_tres_M8), and the measured temperature difference value T_delta is less than the fifth temperature difference safety threshold T_delta_tres_M8 (T_delta<T_delta_tres_M8), it can determine that there is no overheating risk in the outlet water temperature T1, inlet water temperature T2, and engine oil temperature T3 of the engine, and obtain the fault detection result indicating no fault.

[0332] As an example, in step S1104, when the engine is in the hybrid overheating operation mode and the fault detection result indicates a fault, the EMS needs to further evaluate the severity of the fault based on the real-time obtained outlet water temperature T1, inlet water temperature T2, and engine oil temperature T3 to determine the engine fault level, and then execute the target control strategy corresponding to the engine fault level to ensure the safety of the engine.

[0333] In one embodiment, the target temperature thresholds corresponding to the current mode further include a sixth water temperature safety threshold, a sixth oil temperature safety threshold, and a sixth temperature difference safety threshold corresponding to the operation mode after hybrid overheating. The fifth water temperature safety threshold is less than the sixth water temperature safety threshold, the fifth oil temperature safety threshold is less than the sixth oil temperature safety threshold, and the fifth temperature difference safety threshold is less than the sixth temperature difference safety threshold.

[0334] Step S1104, that is, determine the engine fault level according to the outlet water temperature T1, the inlet water temperature T2, and the oil temperature T3, and execute the target control strategy corresponding to the engine fault level, including:

[0335] S11041: If the outlet water temperature T1 is between the fifth water temperature safety threshold and the sixth water temperature safety threshold, the oil temperature T3 is between the fifth oil temperature safety threshold and the sixth oil temperature safety threshold, or the measured temperature difference value is between the fifth temperature difference safety threshold and the sixth temperature difference safety threshold, determine that the engine fault level is the first fault level and record the engine fault level.

[0336] S11042: If the outlet water temperature T1 is greater than or equal to the sixth water temperature safety threshold, the oil temperature T3 is greater than or equal to the sixth oil temperature safety threshold, or the measured temperature difference value is greater than or equal to the sixth temperature difference safety threshold, determine that the engine fault level is the fifth fault level and control the engine to be prohibited from starting for a preset duration.

[0337] Among them, the sixth water temperature safety threshold T1_tres2_M8 is the second safety threshold preset in the operation mode after hybrid overheating for evaluating whether there is an overheating risk in the outlet water temperature T1, and the fifth water temperature safety threshold is less than the sixth water temperature safety threshold. The sixth oil temperature safety threshold T3_tres2_M8 is the second safety threshold preset in the operation mode after hybrid overheating for evaluating whether there is an overheating risk in the oil temperature T3, and the fifth oil temperature safety threshold is less than the sixth oil temperature safety threshold. The sixth temperature difference safety threshold T_delta_tres2_M8 is the second temperature threshold preset in the operation mode after hybrid overheating for evaluating whether there is an overheating risk in the measured temperature difference value, and the fifth temperature difference safety threshold is less than the sixth temperature difference safety threshold.

[0338] As an example, when the engine is in the operation mode after hybrid overheating and the fault detection result is that there is a fault, the EMS can compare the real-time collected outlet water temperature T1 with the preset fifth water temperature safety threshold T1_tres_M8 and the sixth water temperature safety threshold T1_tres2_M8; if the outlet water temperature T1 is between the fifth water temperature safety threshold T1_tres_M8 and the sixth water temperature safety threshold T1_tres2_M8 (i.e., T1_tres_M8 ≤ T1 < T1_tres2_M8), it can be determined that the engine has an overheating risk, but the severity of the fault is small, and the fault bit can be set.

[0339] Bit_error = M0_leakage, determine that the engine fault level is the first fault level, and record the engine fault level. In this example, when the engine fault level is the first fault level, the impact of the fault on the engine and the vehicle operation is relatively small and can be ignored. Therefore, only the fault code corresponding to its engine fault level is stored internally, and no prompt information needs to be output to avoid interfering with the user's normal driving.

[0340] As an example, when the EMS is in the post-hybrid overheat operation mode of the engine and the fault detection result is that there is a fault, the real-time collected oil temperature T3 can be compared with the pre-set fifth oil temperature safety threshold T3_tres_M8 and the sixth oil temperature safety threshold T3_tres2_M8; if the oil temperature T3 is between the fifth oil temperature safety threshold T3_tres_M8 and the sixth oil temperature safety threshold T3_tres2_M8 (i.e., T3_tres_M8 ≤ T3 < T3_tres2_M8), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most serious level. It can be determined that the engine fault level is the fourth fault level, and the engine can be controlled to enter the speed limit working condition to appropriately limit the engine power and avoid further aggravating the fault risk; if the oil temperature T3 is greater than or equal to the sixth oil temperature safety threshold T3_tres2_M8 (i.e., T3 ≥ T3_tres2_M8), it is determined that the engine has an overheat risk and the overheat risk has reached the most serious level. It can be determined that the engine fault level is the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0341] As an example, when the EMS is in the post-hybrid-overheat operation mode and the fault detection result indicates a fault, the measured temperature difference value T_delta can be compared with the pre-set fifth temperature difference safety threshold T_delta_tres_M8 and the sixth temperature difference safety threshold T_delta_tres2_M8; if the measured temperature difference value T_delta is between the fifth temperature difference safety threshold T_delta_tres_M8 and the sixth temperature difference safety threshold T_delta_tres2_M8 (i.e., T_delta_tres_M8 ≤ T_delta < T_delta_tres2_M8), it can be determined that the engine has an overheat risk, and the overheat risk has not reached the most severe level. It can be determined that the engine fault level is the fourth fault level, and the engine can be controlled to enter the speed-limiting working condition to appropriately limit the engine power and avoid further exacerbating the fault risk; if the measured temperature difference value T_delta is greater than or equal to the sixth temperature difference safety threshold T_delta_tres2_M8 (i.e., T_delta ≥ T_delta_tres2_M8), it is determined that the engine has an overheat risk and the overheat risk has reached the most severe level. It can be determined that the engine fault level is the fifth fault level, and the engine is controlled to be prohibited from starting for a preset duration to avoid the overheat risk when starting again after the post-hybrid-overheat operation mode.

[0342] After step S11041, that is, after determining that the engine fault level is the first fault level and recording the engine fault level, the diagnostic control method of the engine cooling system further includes:

[0343] Obtain the engine speed. When the engine speed is not 0, determine that the engine fault level is the fifth fault level and control the engine to enter the idle working condition.

[0344] As an example, when the EMS is in the post-hybrid-overheat operation mode and the fault detection result determined according to the outlet water temperature T1, the inlet water temperature T2, and the oil temperature T3 indicates a fault, the engine speed can be obtained; when the engine speed is 0, it can be considered that the overheat risk is small, maintain the engine fault level as the first fault level, internally store the fault code corresponding to the engine fault level, and there is no need to output a prompt message to avoid interfering with the user's normal driving; when the engine speed is not 0, it can be determined that the overheat risk is the highest, determine that the engine fault level is the fifth fault level, and the engine can be controlled to enter the idle working condition to ensure operation safety.

[0345] In one embodiment, as Fig.12 shown, obtain the heat dissipation deviation value according to the engine speed, engine torque, ambient temperature, outlet water temperature, and inlet water temperature, including:

[0346] S1201: Obtain theoretical heat dissipation according to the engine speed, engine torque and ambient temperature;

[0347] S1202: Obtaining a measured temperature difference value according to the outlet temperature and the inlet temperature;

[0348] S1203: Obtain a first target opening corresponding to the temperature control module and a second target opening corresponding to the bypass valve, and obtain a target flow ratio according to the first target opening and the second target opening;

[0349] S1204: Obtaining actual heat dissipation according to the target flow ratio and the measured temperature difference;

[0350] S1205: Obtain a heat dissipation deviation value according to the theoretical heat dissipation and the actual heat dissipation.

[0351] As an example, in step S1201, the EMS can determine the theoretical heat dissipation QCout according to the engine speed EngSpd, the engine torque EngTorq and the ambient temperature Ta_amb. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq. Then, the EMS queries the theoretical heat dissipation mapping table based on the ambient temperature Ta_amb and the engine power Peng_M0, and obtains the theoretical heat dissipation corresponding to the ambient temperature Ta_amb and the engine power Peng_M0 from the theoretical heat dissipation mapping table. The theoretical heat dissipation mapping table is a pre-set three-dimensional mapping table for reflecting the mapping relationship between the ambient temperature Ta_amb, the engine power Peng_M0 and the theoretical heat dissipation, which can be represented by Map_QCout. For example, when the engine is in the diversion mode, its theoretical heat dissipation mapping table is the first theoretical heat dissipation mapping table corresponding to the diversion mode, and accordingly, its theoretical heat dissipation QCout is the first theoretical heat dissipation QCout_M3; when the engine is in the normal working mode, its theoretical heat dissipation mapping table is the second theoretical heat dissipation mapping table corresponding to the normal working mode, and accordingly, its theoretical heat dissipation QCout is the second theoretical heat dissipation QCout_M4.

[0352] As an example, in step S1202, the EMS can obtain the outlet water temperature T1 and the inlet water temperature T2 of the engine from the measured temperature of the engine; then, according to the outlet water temperature T1 and the inlet water temperature T2 of the engine, the measured temperature difference T_delta of the engine is calculated. In this example, T_delta = T1-T2. The measured temperature difference T_delta can effectively reflect the difference in water temperature between the engine outlet and the engine inlet.

[0353] The first target opening refers to the target opening for controlling the operation of the temperature control mode, and the second target opening refers to the target opening for controlling the operation of the bypass valve.

[0354] As an example, in step S1203, the EMS may obtain the first target opening n_target_TMM of the temperature control module and the second target opening n_target_BPV corresponding to the bypass valve, query the pre-set opening flow ratio table according to the first target opening n_target_TMM and the second target opening n_target_BPV, and obtain the target flow ratio mCout corresponding to the first target opening n_target_TMM and the second target opening n_target_BPV from the opening flow ratio table. Among them, the opening flow ratio table is a pre-set three-dimensional mapping table used to reflect the mapping relationship between the first target opening n_target_TMM, the second target opening n_target_BPV and the flow ratio, which can be represented by Map_mCout. For example, when the engine is in the divert mode, its opening flow ratio table is the first opening flow ratio table corresponding to the divert mode, and accordingly, its target flow ratio mCout is the first target flow ratio; when the engine is in the normal working mode, its opening flow ratio table is the second opening flow ratio table corresponding to the normal working mode, and accordingly, its target flow ratio mCout is the second target flow ratio.

[0355] As an example, in step S1204, EMS can calculate the actual heat dissipation QRout based on the measured temperature difference T_delta and the target flow ratio mCout. Specifically, the actual heat dissipation QRout is calculated using QRout=C*mCout*T_delta, where C refers to specific heat capacity, which is generally considered to be a constant and may actually be slightly corrected according to the temperature.

[0356] As an example, in step S1205, the EMS calculates the heat dissipation deviation value Q_diff according to the theoretical heat dissipation QCout and the actual heat dissipation QRout, and specifically uses Q_diff = (QRout-QCout) / QCout*100 to calculate the heat dissipation deviation value Q_diff, so as to evaluate whether there is a fault according to the heat dissipation deviation value Q_diff. For example, when the engine is in the diversion mode, the heat dissipation deviation value QRout calculated is the first heat dissipation deviation value QRout_M3; when the engine is in the normal working mode, the heat dissipation deviation value QRout calculated is the second heat dissipation deviation value QRout_M4.

[0357] In one embodiment, if Fig.13 As shown, the engine is controlled to enter the speed-limited operating state, including:

[0358] S1301: querying a restriction factor mapping table according to the outlet water temperature and the inlet water temperature to obtain a target restriction factor;

[0359] S1302: Obtaining a maximum allowable torque value according to the actual maximum torque and the target limit factor;

[0360] S1303: Obtaining current required torque according to the engine speed and the engine torque;

[0361] S1304: Determine the smaller value between the current required torque and the maximum allowable torque as the actual output torque, and control the engine operation based on the actual output torque.

[0362] As an example, in step S1301, when the engine is in the current mode, the EMS can query the limiting factor mapping table corresponding to the current mode according to the outlet water temperature T1 and the inlet water temperature T2 to obtain the target limiting factor. The limiting factor mapping table is a pre-set three-dimensional mapping table used to reflect the mapping relationship between the outlet water temperature T1, the inlet water temperature T2 and the limiting factor, which can be represented by Map_safe_limit. The limiting factor mapping table corresponding to each current mode is different. For example, when the current mode is the first heat engine mode, its corresponding limiting factor mapping table is Map_safe_limit_M1. The target limiting factor refers to the limiting factor matched with the outlet water temperature T1 and the inlet water temperature T2 obtained by looking up the table. It is a factor used to implement speed limit processing and can be represented by Cof_limit.

[0363] As an example, in step S1302, the EMS may obtain the actual maximum torque max_aCt_torque of the engine working process, and obtain the maximum permissible torque max_limit_torque according to the actual maximum torque max_aCt_torque and the target limit factor Cof_limit. In this example, the EMS may determine the product of the actual maximum torque max_aCt_torque and the target limit factor Cof_limit as the maximum permissible torque max_limit_torque, that is, max_limit_torque=max_aCt_torque*Cof_limit. Among them, the actual maximum torque max_aCt_torque refers to the maximum torque value in the actual operation of the engine. The maximum permissible torque value is the maximum torque value allowed for use.

[0364] As an example, in step S1303, the EMS may obtain the current required torque req_torque according to the engine speed EngSpd and the engine torque EngTorq. In this example, the EMS first calculates the engine power Peng_M0 according to the engine speed EngSpd and the engine torque EngTorq; then, based on the engine power Peng_M0, it calculates and determines the corresponding current required torque req_torque.

[0365] As an example, in step S1304, the EMS may determine the smaller value between the current required torque req_torque and the maximum allowable torque max_limit_torque as the actual output torque, and control the engine operation based on the actual output torque to achieve operation based on a smaller torque and realize the purpose of speed limiting.

[0366] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0367] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0368] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A diagnostic control method for an engine cooling system, characterized in that: include: When the engine is in the current mode, obtaining measured data, the measured data including the measured temperature of the engine, the measured temperature of the engine being at least one of the outlet water temperature, the inlet water temperature and the oil temperature; Obtaining a target temperature threshold corresponding to the current mode; Acquiring a fault detection result according to the actually measured temperature of the engine and a target temperature threshold corresponding to the current mode; When the fault detection result is that a fault exists, an engine fault level is determined, and a target control strategy corresponding to the engine fault level is executed.

2. The engine cooling system diagnosis and control method according to claim 1, characterized in that: The measured data also includes engine speed, engine torque and ambient temperature; Obtaining a target temperature threshold corresponding to the current mode includes: determining engine power according to the engine speed and the engine torque; According to the ambient temperature and the engine power, a target temperature mapping table corresponding to the current mode is queried to obtain a target temperature threshold corresponding to the current mode.

3. The engine cooling system diagnosis and control method according to claim 1, characterized in that: When the engine is in the current mode, obtaining the measured data includes: When the engine is in a pre-treatment mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature and oil temperature; The obtaining the target temperature threshold corresponding to the current mode includes: acquiring a first maximum allowable temperature difference value corresponding to the preprocessing mode according to the engine speed, the engine torque and the ambient temperature; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: Acquire a fault detection result according to the outlet water temperature, the inlet water temperature and the first maximum allowable temperature difference value corresponding to the pretreatment mode; When the fault detection result is that a fault exists, determining the engine fault level and executing a target control strategy corresponding to the engine fault level include: When the fault detection result is that a fault exists, an engine fault level is determined according to the ambient temperature and the engine oil temperature, and a target control strategy corresponding to the engine fault level is executed.

4. The method for diagnosing and controlling an engine cooling system according to claim 3, characterized in that: The obtaining of the fault detection result according to the outlet water temperature, the inlet water temperature and the first maximum allowable temperature difference corresponding to the pre-processing mode includes: Obtaining a measured temperature difference value according to the outlet water temperature and the inlet water temperature; If the measured temperature difference value is not less than the first maximum allowable temperature difference value corresponding to the preprocessing mode, a fault detection result indicating that a fault exists is obtained; If the measured temperature difference value is less than the first maximum allowable temperature difference value corresponding to the preprocessing mode, a fault detection result indicating that no fault exists is obtained.

5. The engine cooling system diagnosis and control method according to claim 3, characterized in that: When the fault detection result is that a fault exists, determining the engine fault level according to the ambient temperature and the engine oil temperature, and executing a target control strategy corresponding to the engine fault level, includes: When the fault detection result is that a fault exists, querying an oil dilution risk mapping table corresponding to a preprocessing mode according to the ambient temperature and the oil temperature to obtain an oil dilution risk value; If the oil dilution risk value is not less than the first dilution risk threshold, the engine fault level is determined to be the third fault level, the control instrument outputs the first fault prompt information, and the vehicle driving mode is controlled to enter the sports mode; If the oil dilution risk value is less than a first dilution risk threshold, the engine fault level is determined to be a first fault level, and the engine fault level is recorded.

6. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in a first heat engine mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature and engine oil temperature; The obtaining the target temperature threshold corresponding to the current mode includes: acquiring a first engine oil minimum temperature rise value corresponding to the first heat engine mode according to the engine speed, the engine torque and the ambient temperature; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: acquiring a fault detection result according to the engine oil temperature and a first engine oil minimum temperature rise value corresponding to the first heat engine mode; When the fault detection result is that a fault exists, determining the engine fault level and executing a target control strategy corresponding to the engine fault level include: When the fault detection result is that a fault exists, the engine fault level is determined to be a second fault level, and the engine is controlled to enter a first emergency mode.

7. The method for diagnosing and controlling an engine cooling system according to claim 6, wherein: The acquiring of the fault detection result according to the engine oil temperature and the first engine oil minimum temperature rise value corresponding to the first heat engine mode includes: According to all the oil temperatures within the cycle time, obtaining a measured oil change value; If the measured engine oil change value is less than the first engine oil minimum temperature rise value, updating the first abnormality number; If the first abnormal number is greater than the first number threshold, obtaining a fault detection result indicating that a fault exists; If the measured engine oil change value is not less than the first engine oil minimum temperature rise value, or the first abnormal number is not greater than the first number threshold, a fault detection result indicating that no fault exists is obtained.

8. The method for diagnosing and controlling an engine cooling system according to claim 6, wherein: After controlling the engine to enter the first emergency mode, the engine cooling system diagnosis control method further includes: Monitor the emergency operation time corresponding to the engine entering the first emergency mode; If the emergency operation duration is greater than the first duration threshold, the engine is controlled to enter the second heat engine mode.

9. The method for diagnosing and controlling an engine cooling system according to claim 6, wherein: After controlling the engine to enter the first emergency mode, the engine cooling system diagnosis control method further includes: According to all the oil temperatures within the cycle time, obtaining a measured oil change value; If the measured oil change value is less than the temperature fluctuation threshold, updating the second abnormality number; If the second abnormal number is greater than the second number threshold, the engine fault level is determined to be the third fault level, and the engine is controlled to enter the diversion mode.

10. The engine cooling system diagnosis and control method according to claim 6, characterized in that: After controlling the engine to enter the first emergency mode, the engine cooling system diagnosis control method further includes: comparing the outlet water temperature with a first outlet water temperature threshold and a second outlet water temperature threshold, and comparing the inlet water temperature with a first inlet water temperature threshold and a second inlet water temperature threshold; If the outlet water temperature is between the first outlet water temperature threshold and the second outlet water temperature threshold, or the inlet water temperature is between the first inlet water temperature threshold and the second inlet water temperature threshold, the engine fault level is determined to be the fourth fault level, and the engine is controlled to enter the speed limit condition; If the outlet water temperature is greater than or equal to the second outlet water temperature threshold, or the inlet water temperature is greater than or equal to the second inlet water temperature threshold, the engine fault level is determined to be the fifth fault level, and the engine is controlled to enter an idle condition.

11. The method for diagnosing and controlling an engine cooling system according to claim 1, characterized in that: When the engine is in the current mode, obtaining the measured data includes: When the engine is in the second heat engine mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature and air conditioning demand; The obtaining the target temperature threshold corresponding to the current mode includes: If the air conditioning demand is no heating demand, obtaining a first inlet water temperature minimum temperature rise value and a second engine oil temperature minimum temperature rise value corresponding to a non-heating mode according to the engine speed, the engine torque and the ambient temperature; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: Acquire a fault detection result according to the outlet water temperature, the inlet water temperature, the first inlet water temperature minimum temperature rise value, and the second engine oil minimum temperature rise value; When the fault detection result is that a fault exists, determining the engine fault level, and executing a target control strategy corresponding to the engine fault level, including: When the fault detection result is that a fault exists, the engine fault level is determined to be a first fault level, and the engine fault level is recorded.

12. The method for diagnosing and controlling an engine cooling system according to claim 11, characterized in that: The obtaining of the fault detection result according to the outlet water temperature, the inlet water temperature, the first inlet water temperature minimum temperature rise value and the second engine oil minimum temperature rise value comprises: According to all the inlet water temperatures and all the engine oil temperatures within the cycle time, obtain an inlet water temperature change value and a measured engine oil change value; If the inlet water temperature change value is greater than or equal to the first inlet water temperature minimum temperature rise value, and the measured engine oil change value is greater than or equal to the second engine oil minimum temperature rise value, then updating the third abnormality number; If the third abnormal number is greater than the third number threshold, a fault detection result indicating that a fault exists is obtained; If the inlet water temperature change value is less than the first inlet water temperature minimum temperature rise value, the measured engine oil change value is less than the second engine oil minimum temperature rise value, or the third abnormal number is not greater than the third number threshold, a fault detection result indicating that there is no fault is obtained.

13. The method for diagnosing and controlling an engine cooling system according to claim 11, characterized in that: After obtaining measured data when the engine is in the current mode, wherein the measured data includes engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature and air conditioning demand, the engine cooling system diagnosis control method further includes: If the air conditioning demand is a heating demand, obtaining a first inlet water temperature minimum temperature rise value and a second engine oil temperature minimum temperature rise value corresponding to a heating mode; If the inlet water temperature is lower than the first inlet water temperature minimum allowable temperature, or the engine oil temperature is lower than the second engine oil minimum temperature rise value, the engine is controlled to enter the diversion mode.

14. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in the split mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature; The obtaining the target temperature threshold corresponding to the current mode includes: acquiring a first allowable error threshold corresponding to the split mode according to the engine speed, the engine torque and the ambient temperature; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: Acquire a heat dissipation deviation value according to the engine speed, the engine torque, the ambient temperature, the outlet water temperature, and the inlet water temperature, and acquire a fault detection result according to the heat dissipation deviation value and the first allowable error threshold; When the fault detection result is that a fault exists, determining the engine fault level, and executing a target control strategy corresponding to the engine fault level, including: When the fault detection result is that a fault exists, the engine fault level is determined according to the heat dissipation deviation value, and a target control strategy corresponding to the engine fault level is executed.

15. The method for diagnosing and controlling an engine cooling system according to claim 14, characterized in that: The obtaining of a fault detection result according to the heat dissipation deviation value and the first allowable error threshold value includes: If the absolute value of the heat dissipation deviation value is greater than the first allowable error threshold, obtaining a fault detection result indicating that a fault exists; If the absolute value of the heat dissipation deviation value is not greater than the first allowable error threshold, obtaining a fault detection result indicating that no fault exists; Determining the engine fault level according to the heat dissipation deviation value and executing a target control strategy corresponding to the engine fault level includes: If the heat dissipation deviation value is a positive number, determining that the engine fault level is the first fault level, and recording the engine fault level; If the heat dissipation deviation value is a negative number, the engine fault level is determined to be the second fault level, and the engine is controlled to enter a normal working mode.

16. The method for diagnosing and controlling an engine cooling system according to claim 15, characterized in that: If the heat dissipation deviation value is a positive number, the engine fault level is determined to be the first fault level, and after recording the engine fault level, the engine cooling system diagnosis control method further includes: The engine oil temperature is compared with a first oil temperature threshold value. When the engine oil temperature is less than the first oil temperature threshold value, the engine fault level is determined to be a second fault level, the bypass valve is controlled to be closed, and the vehicle driving mode is controlled to enter a sports mode.

17. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in a normal working mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, outlet water temperature, inlet water temperature; The obtaining the target temperature threshold corresponding to the current mode includes: acquiring a second allowable error threshold corresponding to the normal working mode according to the engine speed, the engine torque and the ambient temperature; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: acquiring a heat dissipation deviation value according to the engine speed, the engine torque, the ambient temperature, the outlet water temperature, and the inlet water temperature, and acquiring a fault detection result according to the heat dissipation deviation value and the second allowable error threshold; When the fault detection result is that a fault exists, determining the engine fault level, and executing a target control strategy corresponding to the engine fault level, including: When the fault detection result is that a fault exists, the engine fault level is determined according to the heat dissipation deviation value, and a target control strategy corresponding to the engine fault level is executed.

18. The method for diagnosing and controlling an engine cooling system according to claim 17, wherein: The obtaining of a fault detection result according to the heat dissipation deviation value and the second allowable error threshold value includes: If the absolute value of the heat dissipation deviation value is greater than the second allowable error threshold, obtaining a fault detection result indicating that a fault exists; If the absolute value of the heat dissipation deviation value is not greater than the second allowable error threshold, obtaining a fault detection result indicating that no fault exists; Determining the engine fault level according to the heat dissipation deviation value and executing a target control strategy corresponding to the engine fault level includes: If the heat dissipation deviation value is a positive number, determining that the engine fault level is the first fault level, and recording the engine fault level; If the heat dissipation deviation value is a negative number, the engine fault level is determined to be the third fault level, the control instrument outputs the second fault prompt information, and the engine is controlled to enter the second emergency mode.

19. The method for diagnosing and controlling an engine cooling system according to claim 18, wherein: After determining that the engine fault level is the first fault level and recording the engine fault level, the engine cooling system diagnosis control method further includes: According to the engine oil temperature, obtaining an engine oil temperature rise rate value, comparing the engine oil temperature rise rate value with an engine oil temperature rise rate limit value, and comparing the engine oil temperature with; If the engine oil temperature is lower than the second oil temperature threshold, and the engine oil temperature rise rate value is lower than the engine oil temperature rise rate limit value, then the outlet water temperature is compared with the third outlet water temperature threshold, and the inlet water temperature is compared with the third inlet water temperature threshold; If the outlet water temperature is lower than the third outlet water temperature threshold, and the inlet water temperature is lower than the third inlet water temperature threshold, the engine fault level is determined to be the second fault level, the first target opening of the temperature control module is controlled to be lower than the cooling opening threshold, and the vehicle driving mode is controlled to enter the sports mode.

20. The method for diagnosing and controlling an engine cooling system according to claim 18, wherein: After determining that the engine fault level is the third fault level, the control instrument outputs the second fault prompt information, and the engine is controlled to enter the second emergency mode, the engine cooling system diagnosis control method further includes: comparing the engine oil temperature with a third oil temperature threshold; If the engine oil temperature is lower than the third oil temperature threshold, the engine fault level is determined to be the fourth fault level, and the engine is controlled to enter a speed-limited operating condition.

21. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in an overheating mode, obtaining measured data, the measured data including outlet water temperature, inlet water temperature and oil temperature; The obtaining the target temperature threshold corresponding to the current mode includes: Obtaining a first water temperature safety threshold, a first oil temperature safety threshold, and a first temperature difference safety threshold corresponding to the pre-set overheating mode; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: According to the outlet water temperature and the inlet water temperature, a measured temperature difference is obtained; according to the comparison result of the outlet water temperature and the first water temperature safety threshold, the comparison result of the engine oil temperature threshold and the first oil temperature safety threshold, and the comparison result of the measured temperature difference and the first temperature difference safety threshold, a fault detection result is obtained; When the fault detection result is that a fault exists, determining the engine fault level, and executing a target control strategy corresponding to the engine fault level, including: When the fault detection result is that a fault exists, the engine fault level is determined according to the outlet water temperature, the inlet water temperature and the engine oil temperature, and a target control strategy corresponding to the engine fault level is executed.

22. The method for diagnosing and controlling an engine cooling system according to claim 21, wherein: The obtaining of the fault detection result according to the comparison result between the outlet water temperature and the first water temperature safety threshold, the comparison result between the engine oil temperature threshold and the first oil temperature safety threshold, and the comparison result between the measured temperature difference and the first temperature difference safety threshold includes: If the outlet water temperature is greater than or equal to the first water temperature safety threshold, the engine oil temperature is greater than or equal to the first oil temperature safety threshold, or the measured temperature difference is greater than or equal to the first temperature difference safety threshold, then obtaining a fault detection result indicating that a fault exists; If the outlet water temperature is lower than the first water temperature safety threshold, the engine oil temperature is lower than the first oil temperature safety threshold, and the measured temperature difference is lower than the first temperature difference safety threshold, a fault detection result indicating that no fault exists is obtained.

23. The method for diagnosing and controlling an engine cooling system according to claim 21, wherein: The target temperature threshold corresponding to the current mode also includes a second water temperature safety threshold, a second oil temperature safety threshold, and a second temperature difference safety threshold corresponding to the overheating mode, wherein the first water temperature safety threshold is less than the second water temperature safety threshold, the first oil temperature safety threshold is less than the second oil temperature safety threshold, and the first temperature difference safety threshold is less than the second temperature difference safety threshold; The determining of the engine fault level according to the outlet water temperature, the inlet water temperature and the engine oil temperature, and executing the target control strategy corresponding to the engine fault level, comprises: If the outlet water temperature is between the first water temperature safety threshold and the second water temperature safety threshold, the engine oil temperature is between the first oil temperature safety threshold and the second oil temperature safety threshold, or the measured temperature difference is between the first temperature difference safety threshold and the second temperature difference safety threshold, the engine fault level is determined to be the fourth fault level, and the engine is controlled to enter the speed limit condition; If the outlet water temperature is greater than or equal to the second water temperature safety threshold, the engine oil temperature is greater than or equal to the second oil temperature safety threshold, or the measured temperature difference is greater than or equal to the second temperature difference safety threshold, the engine fault level is determined to be the fifth fault level, and the engine is controlled to enter the idle condition.

24. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in a heat preservation and waste heat utilization mode, obtaining measured data, the measured data including engine speed, engine torque, ambient temperature, inlet water temperature, engine oil temperature and air conditioning demand; The obtaining the target temperature threshold corresponding to the current mode includes: If the air conditioning demand is no heating demand, obtaining the maximum water temperature drop value and the maximum oil temperature drop value corresponding to the non-heating mode according to the engine speed, the engine torque and the ambient temperature; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: Obtaining a fault detection result according to the inlet water temperature, the engine oil temperature, the maximum water temperature drop value, and the maximum engine oil temperature drop value; When the fault detection result is that a fault exists, determining the engine fault level, and executing a target control strategy corresponding to the engine fault level, including: When the fault detection result is that a fault exists, the engine fault level is determined to be a second fault level, and the engine is controlled to enter an idle condition.

25. The method for diagnosing and controlling an engine cooling system according to claim 24, wherein: The obtaining of the fault detection result according to the inlet water temperature, the engine oil temperature, the maximum water temperature drop value and the maximum engine oil temperature drop value comprises: According to all the inlet water temperatures and all the engine oil temperatures within the cycle time, obtain an inlet water temperature change value and a measured engine oil change value; If the absolute value of the inlet water temperature change value is greater than the maximum water temperature drop value, or the absolute value of the measured engine oil change value is greater than the maximum engine oil temperature drop value, then the fourth abnormality number is updated; If the fourth abnormal number is greater than the fourth number threshold, a fault detection result indicating a fault exists is obtained, If the absolute value of the inlet water temperature change value is not greater than the maximum water temperature drop value and the absolute value of the measured oil change value is not greater than the maximum oil temperature drop value, or the fourth abnormal number is not greater than the fourth number threshold, a fault detection result indicating that there is no fault is obtained.

26. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in a start-stop operation mode, obtaining measured data, the measured data including outlet water temperature, inlet water temperature and oil temperature; The obtaining the target temperature threshold corresponding to the current mode includes: Obtaining a third water temperature safety threshold, a third oil temperature safety threshold, and a third temperature difference safety threshold corresponding to the pre-set post-start / stop operation mode; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: According to the outlet water temperature and the inlet water temperature, a measured temperature difference value is obtained; according to the comparison result of the outlet water temperature and the third water temperature safety threshold, the comparison result of the engine oil temperature threshold and the third oil temperature safety threshold, and the comparison result of the measured temperature difference value and the third temperature difference safety threshold, a fault detection result is obtained; When the fault detection result is that a fault exists, determining the engine fault level and executing a target control strategy corresponding to the engine fault level include: When the fault detection result is that a fault exists, the engine fault level is determined according to the engine speed, and a target control strategy corresponding to the engine fault level is executed.

27. The method for diagnosing and controlling an engine cooling system according to claim 26, wherein: The obtaining of the fault detection result according to the comparison result between the outlet water temperature and the third water temperature safety threshold, the comparison result between the engine oil temperature threshold and the third oil temperature safety threshold, and the comparison result between the measured temperature difference and the third temperature difference safety threshold includes: If the outlet water temperature is greater than or equal to the third water temperature safety threshold, the engine oil temperature is greater than or equal to the third oil temperature safety threshold, or the measured temperature difference is greater than or equal to the third temperature difference safety threshold, then obtaining a fault detection result indicating that a fault exists; If the outlet water temperature is lower than the third water temperature safety threshold, the engine oil temperature is lower than the third oil temperature safety threshold, and the measured temperature difference is lower than the third temperature difference safety threshold, a fault detection result indicating that no fault exists is obtained.

28. The method for diagnosing and controlling an engine cooling system according to claim 27, wherein: The target temperature threshold corresponding to the current mode also includes a fourth water temperature safety threshold, a fourth oil temperature safety threshold and a fourth temperature difference safety threshold corresponding to the post-start / stop operation mode, the third water temperature safety threshold is less than the fourth water temperature safety threshold, the third oil temperature safety threshold is less than the fourth oil temperature safety threshold, and the third temperature difference safety threshold is less than the fourth temperature difference safety threshold; The method of determining the engine fault level according to the engine speed and executing the target control strategy corresponding to the engine fault level includes: If the engine speed is 0, determining that the engine fault level is the first fault level, and recording the engine fault level; If the engine speed is not 0, and the outlet water temperature is between the third water temperature safety threshold and the fourth water temperature safety threshold, the engine oil temperature is between the third oil temperature safety threshold and the fourth oil temperature safety threshold, or the measured temperature difference is between the third temperature difference safety threshold and the fourth temperature difference safety threshold, then the engine fault level is determined to be the fourth fault level, and the engine is controlled to enter the speed limit condition; If the engine speed is not 0, and the outlet water temperature is greater than or equal to the fourth water temperature safety threshold, the engine oil temperature is greater than or equal to the fourth oil temperature safety threshold, or the measured temperature difference is greater than or equal to the fourth temperature difference safety threshold, then the engine fault level is determined to be the fifth fault level, and the engine is controlled to enter the idle condition.

29. The method for diagnosing and controlling an engine cooling system according to claim 1, wherein: When the engine is in the current mode, obtaining the measured data includes: When the engine is in a hybrid overheating post-operation mode, obtaining measured data, the measured data including outlet water temperature, inlet water temperature and oil temperature; The obtaining the target temperature threshold corresponding to the current mode includes: Obtaining a fifth water temperature safety threshold, a fifth oil temperature safety threshold, and a fifth temperature difference safety threshold corresponding to the hybrid overheating post-operation mode that is preset; The obtaining the fault detection result according to the actually measured temperature of the engine and the target temperature threshold corresponding to the current mode includes: According to the outlet water temperature and the inlet water temperature, a measured temperature difference value is obtained; according to the comparison result of the outlet water temperature and the fifth water temperature safety threshold, the comparison result of the engine oil temperature threshold and the fifth oil temperature safety threshold, and the comparison result of the measured temperature difference value and the fifth temperature difference safety threshold, a fault detection result is obtained; When the fault detection result is that a fault exists, determining the engine fault level and executing a target control strategy corresponding to the engine fault level include: When the fault detection result is that a fault exists, the engine fault level is determined according to the outlet water temperature, the inlet water temperature and the engine oil temperature, and a target control strategy corresponding to the engine fault level is executed.

30. The method for diagnosing and controlling an engine cooling system according to claim 29, wherein: The obtaining of the fault detection result according to the comparison result between the outlet water temperature and the fifth water temperature safety threshold, the comparison result between the engine oil temperature threshold and the fifth oil temperature safety threshold, and the comparison result between the measured temperature difference and the fifth temperature difference safety threshold includes: If the outlet water temperature is greater than or equal to the fifth water temperature safety threshold, the engine oil temperature is greater than or equal to the fifth oil temperature safety threshold, or the measured temperature difference is greater than or equal to the fifth temperature difference safety threshold, then obtaining a fault detection result indicating that a fault exists; If the outlet water temperature is lower than the fifth water temperature safety threshold, the engine oil temperature is lower than the fifth oil temperature safety threshold, and the measured temperature difference is lower than the fifth temperature difference safety threshold, a fault detection result indicating that no fault exists is obtained.

31. The method for diagnosing and controlling an engine cooling system as claimed in claim 29, wherein: The target temperature threshold corresponding to the current mode also includes a sixth water temperature safety threshold, a sixth oil temperature safety threshold and a sixth temperature difference safety threshold corresponding to the hybrid overheating post-operation mode, the fifth water temperature safety threshold is less than the sixth water temperature safety threshold, the fifth oil temperature safety threshold is less than the sixth oil temperature safety threshold, and the fifth temperature difference safety threshold is less than the sixth temperature difference safety threshold; The determining of the engine fault level according to the outlet water temperature, the inlet water temperature and the engine oil temperature, and executing the target control strategy corresponding to the engine fault level, comprises: If the outlet water temperature is between the fifth water temperature safety threshold and the sixth water temperature safety threshold, the engine oil temperature is between the fifth oil temperature safety threshold and the sixth oil temperature safety threshold, or the measured temperature difference is between the fifth temperature difference safety threshold and the sixth temperature difference safety threshold, then the engine fault level is determined to be the first fault level, and the engine fault level is recorded; If the outlet water temperature is greater than or equal to the sixth water temperature safety threshold, the engine oil temperature is greater than or equal to the sixth oil temperature safety threshold, or the measured temperature difference is greater than or equal to the sixth temperature difference safety threshold, the engine fault level is determined to be the fifth fault level, and the engine is controlled to prohibit starting within a preset time.

32. The method for diagnosing and controlling an engine cooling system as claimed in claim 31, characterized in that: After determining that the engine fault level is the first fault level and recording the engine fault level, the engine cooling system diagnosis control method further includes: The engine speed is obtained, and when the engine speed is not 0, the engine fault level is determined to be the fifth fault level, and the engine is controlled to enter an idle condition.

33. The method for diagnosing and controlling an engine cooling system according to claim 14 or 17, characterized in that: The obtaining of the heat dissipation deviation value according to the engine speed, the engine torque, the ambient temperature, the outlet water temperature and the inlet water temperature comprises: Obtaining theoretical heat dissipation according to the engine speed, the engine torque and the ambient temperature; According to the outlet temperature and the inlet temperature, obtaining a measured temperature difference value; Obtaining a first target opening corresponding to the temperature control module and a second target opening corresponding to the bypass valve, and obtaining a target flow ratio according to the first target opening and the second target opening; Obtaining actual heat dissipation according to the target flow ratio and the measured temperature difference; A heat dissipation deviation value is obtained according to the theoretical heat dissipation and the actual heat dissipation.

34. The method for diagnosing and controlling an engine cooling system according to claim 10, 20, 23 or 28, characterized in that: The controlling the engine to enter a speed-limited operating condition comprises: According to the outlet water temperature and the inlet water temperature, query the restriction factor mapping table to obtain the target restriction factor; Obtaining a maximum allowable torque value according to the actual maximum torque and the target limiting factor; acquiring a current required torque according to the engine speed and the engine torque; The smaller value between the current required torque and the maximum allowable torque is determined as the actual output torque, and the engine operation is controlled based on the actual output torque.

35. An engine controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the diagnostic control method of the engine cooling system according to any one of claims 1 to 34 is implemented.

36. An engine cooling system, characterized in that: The engine controller comprises a cylinder block, a cylinder head, an electronic water pump, a heating branch, a temperature control branch, a first temperature sensor, a second temperature sensor, a third temperature sensor and the engine controller according to claim 35; The cylinder body and the cylinder head cooperate to form a cylinder circulation branch; The warm air branch is arranged between the first outlet of the cylinder head and the inlet of the electronic water pump, and comprises a bypass valve and a warm air core arranged in series; The temperature control branch includes a temperature control module and a radiator, the inlet of the temperature control module is connected to the first outlet of the cylinder body, the outlet of the temperature control module is connected to the inlet of the electronic water pump, or the outlet of the temperature control module is connected to the inlet of the electronic water pump through the radiator; The outlet of the electronic water pump is connected to the first inlet of the cylinder body; The first temperature sensor is arranged at the first outlet of the cylinder body and is used to collect the outlet water temperature of the engine; The second temperature sensor is arranged at the first inlet of the cylinder body and is used to collect the inlet water temperature of the engine; The third temperature sensor is arranged on the cylinder body and is used to collect the oil temperature of the engine; The engine controller is connected to the first temperature sensor, the second temperature sensor, and the third temperature sensor, and is used to perform diagnosis and control according to the outlet water temperature, the inlet water temperature, and the engine oil temperature.

37. A car, characterized in that: Includes the engine cooling system of claim 36.

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