CN114810325B - TMM module leakage fault diagnosis method and device - Google Patents

Abstract

The present application discloses a TMM module fault diagnosis method and device, wherein the TMM module fault diagnosis method includes: judging whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is at It is within the preset vehicle speed range, and whether the fan has no faults; if the judgment result is yes, then when the coolant temperature peaks, the fan will be turned on at the maximum speed; it will be judged whether the fan continues to rotate for more than a period of time; if so, the control will stop the fan ;Learn the engine coolant temperature curve to calculate the temperature difference between a pair of adjacent peaks and troughs, and obtain the coolant temperature drop value. If the temperature drop value is greater than the threshold value, the number of counts is accumulated by 1, and it is judged whether the accumulated value of the number of counts is greater than or equal to the accumulated value. Threshold value; if the judgment result is that the cumulative value of count times is greater than or equal to the cumulative threshold value, it is diagnosed as a leakage fault in the TMM module. The application can ensure accurate diagnosis and low cost.

Description

TMM module leakage fault diagnosis method and device

technical field

The present application relates to the field of vehicle technology, in particular to a method and device for diagnosing a TMM module leakage fault.

Background technique

The TMM (Thermal Management Module) module is an intelligent thermal management module, which can adjust the opening/closing flow of each branch in the cooling system in real time according to the actual working conditions of the vehicle, so as to achieve the functions of fast warm-up and maintaining the optimal working temperature of the system, and achieve better performance. fuel economy performance. As a substitute for the mechanical thermostat, the TMM module also needs to meet the requirements of "need to detect whether the thermostat is working normally" in the National VI regulations. In addition to detecting the working status of the TMM circuit, sensors, and ball valves, it is also necessary to monitor the leakage status of the TMM module (that is, leakage fault). If the temperature of the engine cooling system is abnormal due to a leakage fault of the TMM module, the system should be able to accurately identify the leakage failure state.

At present, the more direct way to determine whether the TMM module has a leakage fault is to calculate the coolant temperature of the engine model, and then use the model temperature and the actual coolant temperature for verification and judgment. However, the engine coolant temperature is affected by many factors such as intake air volume, fuel injection volume, EGR, exhaust gas boosting, warm air, vehicle speed, etc. Therefore, it is more challenging to obtain a more accurate model water temperature. Another way is to use the double water temperature diagnosis method to realize the leakage fault diagnosis of the TMM module. This diagnosis method is to install a water temperature sensor at the water outlet of the radiator. The difference between the water temperature at the engine and the water temperature of the engine can be used to determine whether there is a leakage fault in the TMM module. The above dual water temperature diagnosis method needs to add an additional water temperature sensor in terms of hardware, and needs to select points and drill holes for the radiator, and the hardware cost is relatively high.

Therefore, it is necessary to establish an accurate and low-cost TMM module leakage fault diagnosis method and device, so as to facilitate the diagnosis of whether the TMM module has a leakage fault.

The foregoing description is provided to provide general background information and does not necessarily constitute prior art.

Contents of the invention

The purpose of this application is to provide a TMM module leakage fault diagnosis method and device, which can ensure accurate diagnosis and low cost.

In order to achieve the above object, the technical solution of the present application is achieved in this way:

In the first aspect, the embodiment of the present application provides a TMM module fault diagnosis method, including: judging whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is at the preset speed If the judgment result is yes, turn on the fan at the maximum speed when the coolant temperature peaks; judge whether the fan continues to rotate for more than a period of time; if so, control to stop the fan; learn the engine Coolant temperature curve to calculate the temperature difference between a pair of adjacent peaks and valleys to obtain the temperature drop value of the coolant. If the temperature drop value is greater than the threshold value, the number of counts is accumulated by 1, and it is judged whether the cumulative value of the number of counts is greater than or equal to the cumulative threshold; if If the judging result is that the cumulative value of the counting times is greater than or equal to the cumulative threshold, it is diagnosed as a leak fault in the TMM module.

As one of the implementations, it is judged whether the fan continues to rotate for more than a period of time; if so, then control to stop the fan, also including:

Judging whether the fan continues to run for more than a period of time, or whether there is a trough in the water temperature, or whether the large cycle is turned on, or whether the fan fails, or whether the vehicle speed exceeds the preset speed range, if the judgment result is yes, then the control stops the fan.

As one of the implementation manners, judging before starting the engine also includes:

After the engine is successfully started, it is judged whether the engine starting temperature is lower than the preset temperature, and whether the ambient temperature is higher than the preset ambient temperature;

If the judgment result is that the engine start-up temperature is lower than the preset temperature, and the ambient temperature is higher than the preset ambient temperature, and the TMM module has no sensor and communication faults, then the engine controller judges whether it can read the valid TMM module start Spend;

If the engine controller can read the opening degree of the effective TMM module, judge whether the temperature of the engine coolant is lower than the minimum temperature of the closed-loop control of the TMM module;

If it is lower than the minimum temperature of the closed-loop control of the TMM module, the timer is reset, and the step of judging after the engine is started is performed.

As one of the implementation manners, judging whether the engine coolant temperature is lower than the minimum temperature of the closed-loop control of the TMM module also includes:

If it is judged that it is higher than the minimum temperature of the closed-loop control of the TMM module, start the timer and judge whether the timer time exceeds the threshold time. If the judgment result is that the timer time exceeds the threshold time, it is diagnosed that the TMM module has no leakage fault. If the counted time does not exceed the threshold time, a step of judging whether the temperature of the engine coolant is lower than the minimum temperature of the closed-loop control of the TMM module is performed.

As one of the implementation manners, judging whether the cumulative value of the number of counts is greater than or equal to the cumulative threshold also includes:

If the judging result is that the accumulated value of the number of counts is less than the accumulated threshold, then the engine controller judges whether the opening degree of a valid TMM module can be read.

As one of the implementation manners, judging whether the engine start-up temperature is lower than the preset temperature and whether the ambient temperature is higher than the preset ambient temperature also includes:

If the judgment result is that the starting temperature of the engine is not lower than the preset temperature, and the ambient temperature is not higher than the preset ambient temperature, then the diagnosis is ended.

As one of the implementation manners, the engine controller judges whether the opening degree of the effective TMM module can be read, and also includes:

If the engine controller cannot read the opening degree of the effective TMM module, then end the diagnosis.

In the second aspect, the embodiment of the present application provides a TMM module fault diagnosis device, including: a judgment module before fan startup, a fan startup module, a control fan shutdown module, a temperature drop value calculation module, and a fault judgment module, wherein,

The judging module before the fan is turned on is used to judge whether the coolant has reached a thermal balance after the engine is started, and whether the TMM module has not turned on the large cycle, and whether the vehicle speed is within the preset speed range, and whether the fan is faultless;

The fan start module is used to turn on the fan at the maximum speed when the cooling liquid temperature peaks if the judgment result of the judging module before the fan is turned on is yes;

Control the fan off module, which is used to judge whether the fan continues to rotate for more than a period of time, and if so, control to stop the fan;

The temperature drop value calculation module is used to learn the engine coolant temperature curve to calculate the temperature difference between a pair of adjacent peaks and valleys to obtain the temperature drop value of the coolant. Whether the cumulative value of times is greater than or equal to the cumulative threshold;

The fault judgment module is used for diagnosing that the TMM module has a leakage fault if the judgment result of the temperature drop value calculation module is that the cumulative value of count times is greater than or equal to the cumulative threshold.

The beneficial effects brought by the technical solutions provided by the embodiments of the present application are:

The TMM module fault diagnosis method and device provided in the embodiments of the present application judge whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is within the preset vehicle speed range, and the fan Whether there is no fault; if the judgment result is yes, turn on the fan at the maximum speed when the coolant temperature peaks; judge whether the fan continues to rotate for more than a period of time; if so, control and stop the fan; learn the engine coolant temperature curve, Calculate the temperature difference between a pair of adjacent peaks and troughs to obtain the temperature drop value of the coolant. If the temperature drop value is greater than the threshold value, the number of counts is accumulated by 1, and it is judged whether the cumulative value of the number of counts is greater than or equal to the cumulative threshold; if the judgment result is the number of counts If the cumulative value is greater than or equal to the cumulative threshold, it is diagnosed as a leakage failure of the TMM module. Therefore, this application does not need to add any complicated equipment. By analyzing the difference between the leakage state of the TMM module and the cooling water circuit in the normal state, a method of actively controlling the fan is proposed. The TMM leakage diagnosis can be completed. This method can realize accurate and rapid diagnosis without changing the hardware of the original system, which saves hardware costs. Secondly, it does not need to build a complex model to calculate the temperature of the coolant model, which saves manpower and material costs.

Description of drawings

Fig. 1 is the schematic flow chart of the TMM module fault diagnosis method that the embodiment of the present application provides;

Fig. 2 is a schematic diagram of refinement steps of the TMM module fault diagnosis method of Fig. 1;

FIG. 3 is a block diagram of a TMM module fault diagnosis device provided by an embodiment of the present application.

Detailed ways

The technical solution of the present application will be further elaborated below in combination with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are only for the purpose of describing specific embodiments, and are not intended to limit the application.

FIG. 1 is a schematic flowchart of a TMM module fault diagnosis method provided in the first embodiment of the present application. The method ensures accurate diagnosis and low cost. Please refer to FIG. 1. The TMM module fault diagnosis method of this embodiment may include the following steps:

Step S104, determine whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not turned on the large cycle, and whether the vehicle speed is within the preset vehicle speed range (for example, 30km/h-100km/h), and whether the fan is running Fault, if the judgment result is yes, proceed to step S105, preferably, if the judgment results are all negative, that is, none of the parallel conditions are satisfied, proceed to step S108.

Wherein, this step may also include: resetting the timer.

Step S105, when the coolant temperature peaks, turn on the fan at the maximum speed.

Wherein, when the temperature of the cooling liquid shows a downward inflection point, it is determined that the temperature of the cooling liquid has a peak.

Step S106, determine whether the fan continues to rotate for more than a period of time. In addition, preferably, it can also be determined, for example, 2 minutes, or whether there is a trough in the water temperature, or whether the large cycle is turned on, or whether the fan fails, or whether the vehicle speed exceeds the preset For the vehicle speed range, for example, 30km/h-100km/h, if the judgment result is yes, proceed to step S107; if the judgment result is no, that is, none of the conditions are satisfied, then return to step S105.

Step S107, control to stop the fan from rotating.

Step S108, learn the engine coolant temperature curve to calculate the temperature difference between a pair of adjacent peaks and troughs, that is, the temperature drop value of the coolant, if the temperature drop value is greater than the temperature drop threshold value, the number of counts is accumulated by 1, and the accumulated value of the number of counts is judged Whether it is greater than or equal to the cumulative threshold, for example 3, if the result of the determination is that the cumulative value of counting times is greater than or equal to 3, go to step S109.

Wherein, the engine controller can learn the temperature curve of the engine coolant for the purpose of calculating the temperature difference between a pair of adjacent peaks and troughs, that is, the temperature drop of the coolant. The engine controller judges that the temperature drop of the engine coolant is greater than the temperature drop threshold, then the counter accumulates 1, and judges the number of times the engine coolant temperature drop is greater than the cumulative threshold, and the temperature drop threshold and the cumulative threshold can be set according to actual needs.

Step S109, diagnosing that the TMM module has a leakage fault, and ending the diagnosis.

This application does not need to add any complicated equipment. By analyzing the difference between the leakage state of the TMM module and the cooling waterway in the normal state, a method of actively controlling the fan is proposed to complete the TMM leakage diagnosis. This method can achieve accurate and rapid diagnosis, and There is no need to make hardware changes to the original system, saving hardware costs.

To sum up, the TMM module fault diagnosis method provided by the embodiment of the present application judges whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is within the preset speed range , and the fan is not faulty; if the judgment result is yes, then when the coolant temperature peaks, turn on the fan at the maximum speed; judge whether the fan continues to rotate for more than a period of time; if so, control to stop the fan; learn engine coolant The temperature curve is used to calculate the temperature difference between a pair of adjacent peaks and troughs to obtain the temperature drop value of the coolant. If the temperature drop value is greater than the threshold value, the number of counts is accumulated by 1, and it is judged whether the accumulated value of the number of counts is greater than or equal to the accumulated threshold value; if the judgment result If the cumulative value of the counting times is greater than or equal to the cumulative threshold, it is diagnosed as a leakage failure of the TMM module. Therefore, this application does not need to add any complicated equipment. By analyzing the difference between the leakage state of the TMM module and the cooling water circuit in the normal state, it is proposed to use active control of the fan. TMM leakage diagnosis can be completed by using the method, which can realize accurate and fast diagnosis, and does not need to change the hardware of the original system, which saves hardware costs; secondly, it does not need to build a complex model to calculate the temperature of the coolant model, which saves manpower and material costs .

FIG. 2 is a schematic diagram of detailed steps of the TMM module fault diagnosis method in FIG. 1 . It is similar to the TMM module fault diagnosis method shown in FIG. 1, the difference is that before step 104 in FIG. 2, it may specifically include: steps S101-S103, and may also include steps S110-S111:

Step S101, after the engine is started successfully, judge whether the engine starting temperature is lower than the preset temperature (for example, 60 degrees), and whether the ambient temperature is higher than the preset ambient temperature (for example, -7 degrees), if the judgment result is that the engine starting temperature is low At the preset temperature, and the ambient temperature is higher than the preset ambient temperature, proceed to step S102. Preferably, if one of the conditions is not satisfied, the diagnosis is terminated.

Wherein, after the engine starts successfully, the engine controller can judge whether the engine starting temperature is lower than the preset temperature (for example, 60 degrees) and whether the ambient temperature is higher than the preset ambient temperature (for example- 7 degrees). Wherein, both the starting temperature of the engine and the ambient temperature can be collected by the temperature sensor.

Step S102, the engine controller judges whether the opening degree of the effective TMM module can be read, and if the engine controller can read the opening degree of the effective TMM module, then proceed to step S103, preferably, if the engine controller cannot read the effective opening degree of the TMM module. The opening degree of the TMM module, then end the diagnosis.

Wherein, if the TMM module has no sensor failure, communication failure, etc., the engine controller can read the effective opening of the TMM module. The engine controller can compare the read opening of the TMM module with the opening corresponding to the preset opening of the large cycle, and can determine whether the large cycle is actively opened by reading the TMM opening. The read opening of the TMM module is valid, which is the prerequisite for the subsequent TMM module leakage fault diagnosis process. The TMM module is used to control the temperature of the engine coolant. The TMM module controls the temperature of the engine coolant by opening the opening of the ball valve within a certain angle range. For example, if the opening of the ball valve of the TMM module is greater than 67 degrees, the control will open the large cycle, the engine coolant will flow through the radiator for rapid heat dissipation, and the heat dissipation will be faster, and the fan will have a greater impact on the temperature of the coolant. If the TMM module opens the ball valve If the opening degree is less than 67 degrees, the large circulation will not be controlled, the heat dissipation will be slower, and the fan will have little effect on the coolant temperature.

Step S103, determine whether the engine coolant temperature is lower than the minimum temperature of the closed-loop control of the TMM module, if lower than the minimum temperature of the closed-loop control of the TMM module, then proceed to step S104, preferably, if higher than the minimum temperature of the closed-loop control of the TMM module, enter Step S110.

Step S104, reset the timer, and determine whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is within the preset speed range (for example, 30km/h～100km/h), And whether the fans are not faulty, if the judgment result is yes, proceed to step S105, preferably, if the judgment results are all negative, that is, none of the parallel conditions are satisfied, proceed to step S108.

Wherein, resetting the timer is to reset the value of the timer to zero.

Step S105, when the coolant temperature peaks, turn on the fan at the maximum speed.

Wherein, when the temperature of the cooling liquid shows a downward inflection point, it is determined that the temperature of the cooling liquid has a peak.

Step S106, determine whether the fan continues to rotate for more than a period of time. In addition, preferably, it can also be determined, for example, 2 minutes, or whether there is a trough in the water temperature, or whether the large cycle is turned on, or whether the fan fails, or whether the vehicle speed exceeds the preset For the vehicle speed range, for example, 30km/h-100km/h, if the judgment result is yes, proceed to step S107; if the judgment result is no, that is, none of the conditions are satisfied, then return to step S105.

Step S107, control to stop the fan from rotating.

Step S108, learn the engine coolant temperature curve to calculate the temperature difference between a pair of adjacent peaks and troughs, that is, the temperature drop value of the coolant, if the temperature drop value is greater than the temperature drop threshold value, the number of counts is accumulated by 1, and the accumulated value of the number of counts is judged Whether it is greater than or equal to the accumulation threshold, for example 3, if the judgment result is that the counting times accumulation value is greater than or equal to 3, then proceed to step S109, preferably, if the judgment result is less than 3, then return to step S102.

Wherein, the engine controller can learn the temperature curve of the engine coolant for the purpose of calculating the temperature difference between a pair of adjacent peaks and troughs, that is, the temperature drop of the coolant. The engine controller judges that the temperature drop of the engine coolant is greater than the temperature drop threshold, then the counter accumulates 1, and judges the number of times the engine coolant temperature drop is greater than the cumulative threshold, and the temperature drop threshold and the cumulative threshold can be set according to actual needs.

Step S109, diagnosing that the TMM module has a leakage fault, and ending the diagnosis.

Step S110, start the timer, judge whether the time counted by the timer exceeds the threshold time, if the judgment result is that the time counted by the timer exceeds the threshold time, diagnose that there is no leakage fault in the TMM module, and end the diagnosis, otherwise, if the time counted by the timer does not exceed the threshold value time, go to step S103.

Wherein, in this step, it is judged whether the duration of the engine coolant temperature is greater than the cumulative time of the minimum temperature of the TMM closed-loop control, and whether there is a leakage fault is obtained. In this application, if the TMM module leaks, the engine coolant temperature has gone through a large cycle before the TMM module actively opens the radiator circuit. At this time, the engine coolant passes through the radiator and returns to the engine after being cooled by the radiator. Therefore, the temperature of the engine coolant is greatly affected by the heat dissipation coefficient of the radiator. When the heat dissipation coefficient of the radiator is large, the temperature of the engine coolant rises slowly or even a large temperature drop occurs. When the coefficient of the radiator is small, the temperature of the engine coolant produces a small temperature drop or even May rise faster. To sum up, when the TMM module has a leakage fault, when the TMM module starts a large cycle, the temperature change of the engine coolant has a strong correlation with the heat dissipation coefficient of the radiator. The heat dissipation coefficient of the radiator has a strong correlation with the windward volume of the vehicle, and the windward volume of the vehicle can be controlled by the fan. Therefore, by actively controlling the rotation of the fan to increase the windward volume of the vehicle, and by learning whether the temperature of the engine coolant produces a large temperature drop during the control of the fan, it is possible to identify whether there is a leakage fault in the TMM module. The diagnostic method for actively controlling the fan of the present application is simple, reliable and easy to implement, and avoids the problem of high accuracy requirements for conventional water temperature model verification. TMM leakage fault diagnosis of engine national six OBD cooling system, suitable for leakage fault diagnosis of TMM intelligent temperature regulation module.

To sum up, the TMM module fault diagnosis method provided by the embodiment of the present application judges whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is within the preset speed range , and the fan is not faulty; if the judgment result is yes, then when the coolant temperature peaks, turn on the fan at the maximum speed; judge whether the fan continues to rotate for more than a period of time; if so, control to stop the fan; learn engine coolant The temperature curve is used to calculate the temperature difference between a pair of adjacent peaks and troughs to obtain the temperature drop value of the coolant. If the temperature drop value is greater than the threshold value, the number of counts is accumulated by 1, and it is judged whether the accumulated value of the number of counts is greater than or equal to the accumulated threshold value; if the judgment result If the cumulative value of the counting times is greater than or equal to the cumulative threshold, it is diagnosed as a leakage failure of the TMM module. Therefore, this application does not need to add any complicated equipment. By analyzing the difference between the leakage state of the TMM module and the cooling water circuit in the normal state, it is proposed to use active control of the fan. TMM leakage diagnosis can be completed by using the method, which can realize accurate and fast diagnosis, and does not need to change the hardware of the original system, which saves hardware costs; secondly, it does not need to build a complex model to calculate the temperature of the coolant model, which saves manpower and material costs .

The following are device embodiments of the present application. For details not described in detail in the device embodiments, reference may be made to the corresponding method embodiments above.

Fig. 3 is a block diagram of a TMM module fault diagnosis device provided by an embodiment of the present application. Referring to Fig. 3, the TMM module fault diagnosis device includes: a judgment module 34 before the fan is opened, a fan opening module 35, a control fan closing module 36, a temperature drop value calculation module 37, and a fault judgment module 38, wherein,

The judging module 34 before the fan is turned on is used to judge whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not turned on the large cycle, and whether the vehicle speed is within the preset speed range, and whether the fan is faultless;

The fan opening module 35 is used to open the fan at the maximum speed if the judgment result of the judging module before the fan is opened is yes when the coolant temperature has a peak;

Control the fan to close the module 36, for judging whether the fan continues to rotate for more than a period of time, if so, then control to stop the fan;

The temperature drop calculation module 37 is used to learn the engine coolant temperature curve to calculate the temperature difference between a pair of adjacent peaks and valleys to obtain the coolant temperature drop. Whether the cumulative value of counting times is greater than or equal to the cumulative threshold;

The fault judging module 38 is configured to diagnose a leakage fault in the TMM module if the judgment result of the temperature drop calculation module is that the accumulated value of count times is greater than or equal to the accumulated threshold.

Preferably, the TMM module fault diagnosis device also includes: a starting temperature judging module 31, an opening judging module 32, and a coolant temperature judging module 33;

The starting temperature judging module 31 is used to judge whether the starting temperature of the engine is lower than the preset temperature and whether the ambient temperature is higher than the preset ambient temperature after the engine is started successfully;

Opening judging module 32, is used for if judging result is that engine start-up temperature is lower than preset temperature, and ambient temperature is higher than preset ambient temperature, and TMM module does not have the fault of sensor class and communication class, then engine controller judges whether Read the effective opening of the TMM module;

Coolant temperature judging module 33, is used for if engine controller can read the opening degree of effective TMM module, judges whether engine coolant temperature is lower than the minimum temperature of TMM module closed-loop control, if lower than the minimum temperature of TMM module closed-loop control , the timer is reset, and the judging module before the fan is turned on is executed.

Preferably, the control fan off module 36 is also used to determine whether the fan continues to rotate for more than a period of time, or whether there is a trough in the water temperature, or whether the large circulation is turned on, or whether the fan fails, or whether the vehicle speed exceeds the preset vehicle speed range , if the judgment result is yes, the control stops the fan; or

The coolant temperature judging module 33 is also used for judging that if it is higher than the minimum temperature of the closed-loop control of the TMM module, then start the timer, and judge whether the timing time of the timer exceeds the threshold time, and if the judgment result is that the timing time of the timer exceeds the threshold time, the diagnosis is There is no leakage fault in the TMM module, if the timer time does not exceed the threshold time, execute the coolant temperature judgment module to judge whether the engine coolant temperature is lower than the minimum temperature of the closed-loop control of the TMM module; or

The temperature drop calculation module 37 is also used for if the result of the judgment is that the cumulative value of the number of counts is less than the cumulative threshold, then execute the engine controller in the opening judgment module to judge whether the opening of an effective TMM module can be read; or

The starting temperature judging module 31 is also used to end the diagnosis if the judging result is that the engine starting temperature is not lower than the preset temperature and the ambient temperature is not higher than the preset ambient temperature; or

The opening degree judging module 32 is also used for ending the diagnosis if the engine controller cannot read the effective opening degree of the TMM module. Wherein, all the modules mentioned above can be set in the engine controller.

To sum up, the TMM module fault diagnosis device provided by the embodiment of the present application judges whether the coolant has reached thermal equilibrium once after the engine is started, and whether the TMM module has not started a large cycle, and whether the vehicle speed is within the preset speed range , and the fan is not faulty; if the judgment result is yes, then when the coolant temperature peaks, turn on the fan at the maximum speed; judge whether the fan continues to rotate for more than a period of time; if so, control to stop the fan; learn engine coolant The temperature curve is used to calculate the temperature difference between a pair of adjacent peaks and troughs to obtain the temperature drop value of the coolant. If the temperature drop value is greater than the threshold value, the number of counts is accumulated by 1, and it is judged whether the accumulated value of the number of counts is greater than or equal to the accumulated threshold value; if the judgment result If the cumulative value of the counting times is greater than or equal to the cumulative threshold, it is diagnosed as a leakage failure of the TMM module. Therefore, this application does not need to add any complicated equipment. By analyzing the difference between the leakage state of the TMM module and the cooling water circuit in the normal state, it is proposed to use active control of the fan. TMM leakage diagnosis can be completed by using the method, which can realize accurate and fast diagnosis, and does not need to change the hardware of the original system, which saves hardware costs; secondly, it does not need to build a complex model to calculate the temperature of the coolant model, which saves manpower and material costs .

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

It should be noted that, in this document, the term "comprising", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, It also includes other elements not expressly listed, or elements inherent in the process, method, article, or device. Without further limitations, an element defined by the statement "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element. In addition, different implementations of the present application Components, features, and elements with the same name in the example may have the same meaning, or may have different meanings, and the specific meaning shall be determined based on the explanation in the specific embodiment or further combined with the context in the specific embodiment.

It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, the information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this document, first information may also be called second information, and similarly, second information may also be called first information. Depending on the context, the word "if" as used herein may be interpreted as "at" or "when" or "in response to a determination". Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms "comprising", "comprising" indicate the presence of stated features, steps, operations, elements, components, items, species, and/or groups, but do not exclude one or more other features, steps, operations, The existence, occurrence or addition of an element, component, item, species, and/or group. The terms "or" and "and/or" as used herein are to be construed as inclusive, or to mean either one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C" . Exceptions to this definition will only arise when combinations of elements, functions, steps or operations are inherently mutually exclusive in some way.

It should be understood that although the various steps in the flow chart in the embodiment of the present application are displayed sequentially according to the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the figure may include multiple sub-steps or multiple stages, these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, and the execution order is not necessarily sequential Instead, it may be performed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims (8)

1. A TMM module fault diagnosis method, characterized by comprising:

after the engine is successfully started, judging whether the starting temperature of the engine is lower than a preset temperature and whether the ambient temperature is higher than the preset ambient temperature;

if the judgment result is that the engine starting temperature is lower than the preset temperature and the environment temperature is higher than the preset environment temperature, and the TMM module has no faults of sensors and communication, the engine controller judges whether the opening of the effective TMM module can be read;

if the engine controller can read the opening degree of the effective TMM module, judging whether the temperature of the engine coolant is lower than the lowest temperature of the closed-loop control of the TMM module;

when the temperature of the cooling liquid of the engine is lower than the lowest temperature of the closed-loop control of the TMM module, judging whether the cooling liquid reaches primary heat balance, whether the TMM module does not start large circulation, whether the vehicle speed is in a preset vehicle speed range and whether a fan has no fault;

if the judgment result is yes, when the temperature of the cooling liquid has a peak, the fan is started at the maximum;

judging whether the duration time of the fan exceeds a period of time;

if yes, controlling to stop rotating the fan;

learning an engine coolant temperature curve to calculate the temperature difference between a pair of adjacent wave peaks and wave troughs to obtain a coolant temperature drop value, wherein the temperature drop value is larger than a threshold value, the counting times are accumulated by 1, and judging whether the counting times accumulated value is larger than or equal to an accumulated threshold value;

if the judgment result is that the counting times accumulated value is larger than or equal to the accumulated threshold value, diagnosing that the TMM module has leakage faults.

2. The method of claim 1, wherein determining whether the fan has been rotated for a duration of time exceeding a period of time; if yes, control to stop rotating the fan, still include:

judging whether the continuous rotation time of the fan exceeds a period of time, or whether the water temperature is in a trough state, or whether the large circulation is started, or whether the fan fails, or whether the vehicle speed exceeds a preset vehicle speed range, if so, controlling to stop rotating the fan.

3. The method of claim 1, wherein determining whether the engine coolant temperature is below a minimum temperature for closed loop control of the TMM module further comprises:

if the temperature is higher than the lowest temperature of the TMM module closed-loop control, starting a timer, judging whether the timing time of the timer exceeds the threshold time, if the judgment result is that the timing time of the timer exceeds the threshold time, diagnosing that the TMM module has no leakage fault, and if the timing time of the timer does not exceed the threshold time, judging whether the temperature of the engine coolant is lower than the lowest temperature of the TMM module closed-loop control.

4. The method of claim 1, wherein determining whether the count-number accumulation value is equal to or greater than an accumulation threshold value further comprises:

and if the judgment result is that the count number accumulated value is smaller than the accumulated threshold value, the step of judging whether the opening of the effective TMM module can be read by the engine controller is performed.

5. The method of claim 1, wherein determining whether the engine start temperature is below a preset temperature and whether the ambient temperature is above a preset ambient temperature further comprises:

if the judgment result is that the engine starting temperature is not lower than the preset temperature and the environment temperature is not higher than the preset environment temperature, ending the diagnosis.

6. The method of claim 1, wherein the engine controller determining whether the opening of the valid TMM module is readable further comprises:

if the opening degree of the effective TMM module cannot be read by the engine controller, the diagnosis is ended.

7. A TMM module failure diagnosis apparatus, characterized by comprising: a judging module before the fan is started, a fan starting module, a fan closing control module, a temperature drop value calculating module, a fault judging module, a starting temperature judging module, an opening judging module and a cooling liquid temperature judging module, wherein,

the judging module before the fan is started is used for judging whether the cooling liquid reaches primary heat balance after the engine is started, whether the TMM module does not start large circulation, whether the speed of the vehicle is in a preset speed range and whether the fan has no fault;

the fan starting module is used for starting the fan at the maximum when the temperature of the cooling liquid has a peak if the judgment result of the judgment module before the fan is started is yes;

the control fan closing module is used for judging whether the continuous rotation time of the fan exceeds a period of time, and if so, stopping rotating the fan;

the temperature drop value calculation module is used for learning a temperature curve of the engine cooling liquid so as to calculate the temperature difference between a pair of adjacent wave peaks and wave troughs to obtain a cooling liquid temperature drop value, wherein the temperature drop value is larger than a threshold value, the counting times are accumulated by 1, and whether the counting times accumulated value is larger than or equal to an accumulated threshold value is judged;

the fault judging module is used for diagnosing that the TMM module has leakage fault if the temperature drop value calculating module judges that the counting times accumulated value is more than or equal to the accumulated threshold value;

the starting temperature judging module is used for judging whether the starting temperature of the engine is lower than a preset temperature or not and whether the ambient temperature is higher than the preset ambient temperature or not after the engine is successfully started;

the opening judging module is used for judging whether the opening of the effective TMM module can be read or not if the judging result is that the engine starting temperature is lower than the preset temperature and the environment temperature is higher than the preset environment temperature and the TMM module has no faults of sensors and communication;

and the cooling liquid temperature judging module is used for judging whether the temperature of the cooling liquid of the engine is lower than the lowest temperature of the closed-loop control of the TMM module or not if the opening of the effective TMM module can be read by the engine controller, resetting the timer if the temperature of the cooling liquid of the engine is lower than the lowest temperature of the closed-loop control of the TMM module, and executing the judging module before the fan is started.

8. The apparatus of claim 7, wherein the control fan shut-off module is further configured to determine whether the fan continues to rotate for a period of time, whether a trough occurs in the water temperature, whether a large cycle is turned on, whether the fan fails, or whether the vehicle speed exceeds a preset vehicle speed range, and if so, to control the fan to stop rotating; or alternatively

The cooling liquid temperature judging module is also used for judging whether the timing time of the timer exceeds the threshold time or not if the timing time of the timer exceeds the threshold time, diagnosing that the TMM module has no leakage fault, and executing the cooling liquid temperature judging module to judge whether the cooling liquid temperature of the engine is lower than the lowest temperature of the TMM module in the closed-loop control mode if the timing time of the timer does not exceed the threshold time; or alternatively

The temperature drop value calculation module is further used for executing the engine controller in the opening degree judgment module to judge whether the opening degree of the effective TMM module can be read or not if the judgment result is that the accumulated value of the counting times is smaller than the accumulated threshold value; or alternatively

The starting temperature judging module is also used for ending diagnosis if the judging result is that the starting temperature of the engine is not lower than the preset temperature and the ambient temperature is not higher than the preset ambient temperature; or alternatively

The opening degree judging module is also used for ending diagnosis if the opening degree of the effective TMM module can not be read by the engine controller.

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