Spark plug abnormality determination method and parking heater

Abstract

The invention provides a spark plug abnormity judgment method and a parking heater, the spark plug abnormity judgment method is applied to the parking heater, the parking heater comprises a spark plug, and the method comprises the steps that current is provided for the spark plug to ignite when the parking heater is started, detecting a first resistance value of the spark plug; after the spark plug continuously works for a first duration, reducing the current, and detecting a second resistance value of the spark plug; and comparing the first resistance value with the second resistance value to determine whether the spark plug has abnormal ignition or not.

Description

Technical Field

[0001] This application relates to the field of heater technology, and in particular to a spark plug malfunction detection method and a parking heater. Background Technology

[0002] In a parking heater (or fuel heater), heat is generated by fuel combustion through a heat exchanger. If the spark plug fails to ignite properly during the heating process, and the fuel injector or fuel pump is continuously injecting fuel into the combustion chamber, ignition failure can easily occur, leading to problems such as white smoke or carbon buildup in the combustion chamber. Summary of the Invention

[0003] To address the existing technical problems, this application provides a spark plug malfunction detection method and a parking heater that can accurately determine ignition abnormalities.

[0004] In a first aspect, embodiments of this application provide a spark plug malfunction judgment method applied to a parking heater, the parking heater including a spark plug, the method comprising: providing current to the spark plug for ignition when the parking heater is started, and detecting a first resistance value of the spark plug; reducing the current in response to the spark plug continuously operating for a first duration, and detecting a second resistance value of the spark plug; and determining whether the spark plug has an ignition malfunction by comparing the first resistance value and the second resistance value.

[0005] Secondly, embodiments of this application provide a parking heater, including a control module, which is used to execute the spark plug malfunction judgment method described in any embodiment of this application.

[0006] In the spark plug malfunction determination method provided in the above embodiment, when the parking heater is started, current is supplied to the spark plug for ignition, and a first resistance value of the spark plug is detected; in response to the spark plug continuously operating for a first period of time, the current is reduced, and a second resistance value of the spark plug is detected; by comparing the first resistance value and the second resistance value, it is determined whether the spark plug has an ignition malfunction. Thus, after the spark plug successfully ignites for a period of time, the current is reduced to maintain the high temperature of the spark plug by relying on the high combustion temperature to continue igniting the fuel. Based on the comparison of the resistance value at this time with the first resistance value when ignition was successful for the first time, it can be determined whether the spark plug is in a state where it can continue to ignite, thereby determining whether an ignition malfunction has occurred. This greatly improves the detection efficiency of spark plug malfunctions and avoids malfunctions caused by ignition failure.

[0007] The parking heater provided in the above embodiments belongs to the same concept as the corresponding spark plug malfunction judgment method embodiments, and thus has the same technical effect as the corresponding spark plug malfunction judgment method embodiments, which will not be repeated here. Attached Figure Description

[0008] Figure 1 This is a flowchart illustrating a spark plug malfunction detection method in one embodiment of this application. Figure 2 This is a flowchart illustrating a spark plug malfunction detection method in another embodiment of this application. Figure 3 This is a flowchart illustrating a spark plug malfunction detection method in another embodiment of this application. Detailed Implementation

[0009] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0010] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0011] In the following description, the phrase "some embodiments" refers to a subset of all possible embodiments. It should be noted that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0012] In the following description, the terms "first," "second," and "third" are used merely to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that "first," "second," and "third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0013] like Figure 1 As shown in the figure, this application provides a spark plug malfunction judgment method, including: S10: When the parking heater is started, current is supplied to the spark plug to ignite the spark plug, and the first resistance value of the spark plug is detected.

[0014] In one embodiment, the parking heater may also be called a fuel heater, etc., which is an auxiliary heater that provides heat based on fuel combustion.

[0015] In one embodiment, the parking heater may include a spark plug (or ignition plug, etc.) for igniting fuel, and the resistance value of the spark plug can be detected by the control module through a port electrically connected to the spark plug.

[0016] In one embodiment, the above steps may include: supplying current to the spark plug when the parking heater is activated so that the spark plug can complete the first ignition, and detecting the first resistance value of the spark plug after the first ignition is successful.

[0017] In one embodiment, the first resistance value may be the average resistance value of the spark plug during a first period of continuous operation, and the first period of continuous operation may be the first period of continuous operation after the spark plug successfully ignites for the first time.

[0018] For example, detecting the first resistance value of the spark plug can include: detecting the resistance value multiple times within a first period after the spark plug's first ignition, and calculating the average of the multiple detected resistance values ​​as the first resistance value. In this way, the first resistance value can more accurately represent the reference resistance value corresponding to the spark plug's ignition function under stable operating conditions.

[0019] S20: In response to the spark plug continuously operating for a first duration, reduce the current and detect the second resistance value of the spark plug.

[0020] In one embodiment, the spark plug's continuous operation for a first duration can refer to the duration during which the spark plug continues to operate after completing the first ignition, such as the spark plug continuously igniting within the first duration.

[0021] In one embodiment, reducing the current can mean that the current provided by the spark plug is less than the current provided to the spark plug when the parking heater is started. This can reduce power consumption and maintain the high temperature of the spark plug to maintain the ignition function by relying on the high temperature generated by fuel combustion under stable ignition conditions.

[0022] In one embodiment, detecting the second resistance value of the spark plug may refer to detecting the second resistance value of the spark plug after the current is reduced.

[0023] Alternatively, detecting the second resistance value of the spark plug can refer to detecting the second resistance value of the spark plug after a preset time period of reducing the current.

[0024] Alternatively, detecting the second resistance value of the spark plug can refer to repeatedly detecting the resistance value of the spark plug within a preset time period after the current is reduced, and determining the average value of the multiple detections as the second resistance value. Here, the preset time period can be a third time period.

[0025] S30: By comparing the first resistance value and the second resistance value, determine whether the spark plug has an ignition abnormality.

[0026] In one embodiment, step S30 may include: calculating a first absolute value of the difference between the first resistance value and the second resistance value; and determining whether the spark plug has an ignition abnormality based on a comparison of the first absolute value and a first threshold.

[0027] For example, it may include calculating a first absolute value of the difference between the first resistance value and the second resistance value; and determining that the spark plug has an ignition abnormality in response to the first absolute value being greater than a first threshold.

[0028] The first threshold can be a fixed value, or it can be a value corresponding to the current operating gear.

[0029] In one embodiment, the parking heater may have multiple operating levels, with different heat outputs at different operating levels. For example, the fan speed, oil pumping volume, and / or oil pumping frequency of the parking heater may differ at different operating levels.

[0030] In this way, after the spark plug has successfully ignited for a period of time, the current is reduced to maintain the high temperature of the spark plug by relying on the high temperature of combustion, so as to continue to ignite the fuel. By comparing the resistance value at this time with the first resistance value when the first ignition was successful, it can be determined whether the spark plug is in a state that can continue to ignite, thereby determining whether there is an ignition abnormality. This greatly improves the detection efficiency of spark plug failure and avoids abnormalities caused by ignition failure.

[0031] In some embodiments, such as Figure 2 As shown, determining whether the spark plug has an ignition abnormality by comparing the first resistance value and the second resistance value includes: S31: Calculate the first absolute value of the difference between the first resistance value and the second resistance value; S32: In response to the first absolute value being greater than the first threshold, it is determined that the spark plug has an ignition abnormality.

[0032] In one embodiment, step S32 may include: in response to the first absolute value being greater than a first threshold, determining whether the spark plug has an ignition abnormality based on the operating data of the parking heater.

[0033] In one embodiment, the operating data may include at least one of the following: the heat exchanger temperature of the parking heater, the operating time of the parking heater at each operating level, the number of times the parking heater is started, and the number of times the parking heater fails to ignite.

[0034] The operating data for the parking heater refers to the relevant operational data of the parking heater. The parking heater includes a burner and a heat exchanger. The heat exchanger, enclosed by the burner, is a device used for heat exchange with incoming air. Its outer surface heats the incoming air before it is discharged as hot air. The heat exchanger temperature refers to the surface temperature of the heat exchanger, which can be obtained through a temperature sensor located on its surface. The exhaust gas temperature refers to the temperature of the exhaust gas generated by the parking heater and discharged through the exhaust pipe, which can be obtained through a temperature sensor located in the exhaust pipe or on its inner or outer surface.

[0035] In one embodiment, determining whether the spark plug has an ignition abnormality based on the parking heater's operating data in response to the first absolute value being greater than a first threshold may include: in response to the first absolute value being greater than the first threshold, acquiring the heat exchanger temperature and the ambient temperature; calculating a second absolute value of the difference between the heat exchanger temperature and the ambient temperature; and in response to the second absolute value being less than or equal to the second threshold, determining that the spark plug has an ignition abnormality.

[0036] Thus, based on the difference between the spark plug's resistance value and the reference resistance value after the current is reduced, it can be determined whether the spark plug's resistance value changes too much before and after the current is reduced. If the resistance value changes too much, it indicates that the spark plug's temperature is insufficient for ignition, and there may be an abnormal situation of ignition failure.

[0037] In some embodiments, the parking heater further includes a heat exchanger, and the method further includes: In response to the first absolute value being less than or equal to a first threshold, the heat exchanger temperature and the ambient temperature are obtained; Calculate the second absolute value of the difference between the heat exchanger temperature and the ambient temperature; In response to the second absolute value being greater than the second threshold, it is determined that the spark plug is igniting normally.

[0038] In one embodiment, the heat exchanger temperature can refer to the surface temperature of the heat exchanger, that is, the temperature of the aluminum body of the heat exchanger. For example, the heat exchanger temperature can be obtained by a first temperature sensor disposed on the surface of the aluminum body of the heat exchanger.

[0039] In one embodiment, the ambient temperature can refer to the temperature of the air drawn into the heat exchanger. For example, the ambient temperature can be obtained by a second temperature sensor located at the air inlet of the heat exchanger.

[0040] In one embodiment, the first threshold may be a first threshold corresponding to the current operating gear. For example, the method may further include: determining the current operating gear of the parking heater; and obtaining the first threshold corresponding to the current operating gear.

[0041] Thus, if the change in spark plug resistance does not exceed the first threshold, the combustion status can be determined by whether the heat exchanger temperature exceeds a certain value of the ambient temperature. When the difference between the heat exchanger temperature and the ambient temperature is large enough, it can be confirmed that the spark plug ignition is in normal condition.

[0042] In some embodiments, before determining that the spark plug ignition is normal in response to the second absolute value being greater than a second threshold, the method may further include: Determine the current operating level of the parking heater; Obtain the second threshold corresponding to the current operating gear.

[0043] In one embodiment, the second threshold represents the range of differences between the heat exchanger temperature and the ambient temperature that should exist when ignition is normal at the current operating setting.

[0044] In one embodiment, the first threshold characterizes the range of change in spark plug resistance value before and after the current decreases when ignition is normal in the current operating gear.

[0045] In one embodiment, the first threshold is different for different operating levels.

[0046] In one embodiment, the second threshold is different for different operating levels.

[0047] Therefore, by determining the corresponding second threshold based on the current operating gear, the threshold can be matched more accurately with the combustion status of the parking heater at the current gear, avoiding misjudgment caused by the comparison threshold not matching the actual current combustion status.

[0048] In some embodiments, determining that the spark plug ignition is normal in response to the second absolute value being greater than a second threshold includes: In response to the second absolute value being greater than the second threshold, the change of the second absolute value within the first time period is determined; If the change in the second absolute value meets the first preset condition, it is determined that the spark plug is igniting normally.

[0049] In one embodiment, when the parking heater is started, current is supplied to the spark plug to ignite the spark plug, and after detecting the first resistance value of the spark plug, the heat exchanger temperature and the ambient temperature are detected multiple times within a first time period, and the second absolute value corresponding to each detection is calculated.

[0050] Among them, multiple detections of heat exchanger temperature and ambient temperature can refer to detection at multiple times, with the heat exchanger temperature and ambient temperature being detected separately at each time, and the second absolute value of the difference between the two being calculated.

[0051] In one embodiment, the change of the second absolute value within the first time period may include the trend of the second absolute value within the first time period, such as a trend of continuous increase, continuous decrease, increase followed by decrease, decrease followed by increase, etc. It may also include the rate of change and amount of change of the second absolute value within the first time period.

[0052] In one embodiment, the first preset condition characterizes the change in the temperature difference between the heat exchanger and the ambient temperature within a first duration under normal ignition conditions. For example, the first preset condition may include at least one of the following: the trend of change of the second absolute value within the first duration, the amount of change, and the rate of change.

[0053] In one embodiment, the first preset condition includes at least one of the following: The trend is one of continuous increase; The change is greater than the third threshold; The rate of change is greater than the fourth threshold.

[0054] In one embodiment, the trend of change is a continuous increase, which can mean that the second absolute value continues to increase within the first time period. That is, for any first moment within the first time period, the second absolute value corresponding to any second moment after the first moment is greater than the second absolute value corresponding to the first moment.

[0055] In one embodiment, the change amount being greater than the third threshold can be the second absolute value corresponding to the end time of the first duration, and the difference between the second absolute value corresponding to the start time of the first duration and the second absolute value is greater than the third threshold.

[0056] In one embodiment, a rate of change greater than the fourth threshold can refer to the difference between the second absolute value corresponding to the end time of the first duration and the second absolute value corresponding to the start time of the first duration, which, when divided by the first duration, is greater than the fourth threshold.

[0057] In one embodiment, when the first preset condition includes two or more of the above-mentioned conditions, the change of the second absolute value meets the first preset condition. This can mean that the change of the second absolute value meets any one of the first preset conditions, or that the change of the second absolute value meets all of the first preset conditions.

[0058] Thus, by analyzing the changes in the second absolute value within the first time period, the change in the difference between the heat exchanger temperature and the ambient temperature before and after reducing the current can be characterized. Based on preset conditions, it is possible to accurately determine whether the change in the heat exchanger temperature is in line with the normal state, and thus determine whether it is in a normal ignition state.

[0059] In some embodiments, determining that the spark plug has an ignition abnormality in response to the first absolute value being greater than a first threshold may include: In response to the first absolute value being greater than a first threshold, the second resistance value is detected multiple times within a second time period, and the corresponding first absolute value is calculated. In response to the fact that the change of the first absolute value within the second time period meets the second preset condition, it is determined that the spark plug has an ignition abnormality.

[0060] In one embodiment, the second duration may be less than the first duration, or it may be greater than or equal to the first duration.

[0061] In one embodiment, the second resistance value is detected multiple times within a second time period, that is, multiple times within a second time period after the current is reduced. For example, the second resistance value is detected at multiple moments within the second time period, and a first absolute value corresponding to each detected second resistance value is calculated.

[0062] In one embodiment, the change of the first absolute value within the second time period may include the trend of the first absolute value within the second time period, such as a trend of continuous increase, continuous decrease, first increase and then decrease, first decrease and then increase, etc., and may also include the rate of change and amount of change of the first absolute value within the second time period.

[0063] In one embodiment, the second preset condition characterizes the change in the difference between the second resistance value and the first resistance value within a second time period under normal ignition conditions. For example, the second preset condition may include at least one of the following: the trend of change of the first absolute value, the amount of change, and the rate of change within the second time period.

[0064] In some embodiments, the second preset condition includes at least one of the following: The trend is one of continuous increase; The change exceeds the fifth threshold; The rate of change is greater than the sixth threshold.

[0065] In one embodiment, the trend of change is a continuous increase, which can mean that the first absolute value continues to increase within the second time period. That is, for any third time point within the second time period, the first absolute value corresponding to any fourth time point after the third time point is greater than the first absolute value corresponding to the third time point.

[0066] In one embodiment, the change amount being greater than the fifth threshold can be the difference between the first absolute value corresponding to the end time of the second duration and the first absolute value corresponding to the start time of the second duration being greater than the fifth threshold.

[0067] In one embodiment, a rate of change greater than the sixth threshold can refer to the difference between the first absolute value corresponding to the end time of the second duration and the first absolute value corresponding to the start time of the second duration, which, when divided by the first duration, is greater than the sixth threshold.

[0068] In one embodiment, when the second preset condition includes two or more of the above-mentioned conditions, the change of the first absolute value meets the second preset condition. This can mean that the change of the first absolute value meets any one of the second preset conditions, or that the change of the first absolute value meets all of the second preset conditions.

[0069] Thus, by analyzing the changes in the first absolute value within the second time period, the changes in the spark plug resistance value before and after reducing the current can be characterized. Based on preset conditions, it is possible to accurately determine whether the change in the spark plug resistance value conforms to the normal state, and thus determine whether it is in a normal ignition state.

[0070] In some embodiments, detecting the second resistance value of the spark plug includes: The second resistance value of the spark plug is detected according to a preset detection cycle or preset detection frequency.

[0071] like Figure 3 As shown, step S20 may include: S21: In response to the spark plug continuously operating for a first duration, reduce the current and detect the second resistance value of the spark plug according to a preset detection cycle or preset detection frequency.

[0072] In one embodiment, the preset detection cycle or preset detection frequency can be a preset fixed value, or it can be determined based on the current operating gear, for example, different operating gears correspond to different preset detection cycles or preset detection frequencies.

[0073] In one embodiment, the preset detection cycle or preset detection frequency can also be determined or adjusted based on the current operating data of the parking heater. For example, the preset detection cycle or preset detection frequency is different at different heat exchanger temperatures.

[0074] In this way, by continuously testing the second resistance value according to a certain testing cycle or frequency, abnormal changes in the spark plug resistance value can be detected in a timely manner, and the ignition abnormality of the parking heater can be continuously monitored during the overall operation to avoid ignition failure.

[0075] In one embodiment, after determining that the spark plug has an ignition abnormality, the pumping action of the oil pump or nozzle can be stopped, for example, the operation of the oil pump or nozzle can be stopped, and the operation of the blower can also be stopped.

[0076] In one embodiment, after determining that the spark plug has an ignition abnormality, an alarm message can also be output. For example, the alarm message can be output in any one or more ways such as light emission, buzzer, text display, icon display, or voice output to remind the user that the spark plug has an ignition abnormality.

[0077] As one possible implementation, this application provides a heater ignition determination method, which may specifically include: During the ignition process, a relatively high current needs to be supplied to the spark plug during the initial ignition to bring it to a high temperature and achieve ignition. At this point, the initial resistance value of the spark plug is read and used as the reference resistance value.

[0078] After the spark plug has been working for a period of time, its power is reduced, meaning the current is decreased. At this point, the high temperature generated by fuel combustion is mainly used to maintain the spark plug's high temperature, allowing it to continuously ignite the fuel. During this state, the spark plug's second resistance value is continuously monitored and used as the detection resistance value. This value is compared with a reference resistance value. If the difference is within a preset range, the spark plug is considered normal and ignition is successful. If the difference between the reference resistance value and the detection resistance value exceeds the preset value, ignition is considered to have failed, and the user is notified of an ignition error.

[0079] Furthermore, a first temperature sensor is installed on the aluminum body of the heat exchanger, and a second temperature sensor is installed at the air inlet of the heat exchanger. Then, the resistance value of the spark plug, the temperature value of the aluminum body (i.e., the temperature of the heat exchanger), and the ambient temperature value are read. The spark plug resistance value is compared with the reference resistance value, and the aluminum body temperature is compared with the ambient temperature. If the difference between the spark plug resistance value and the reference resistance value is within the preset range, and the difference between the aluminum body temperature and the ambient temperature is greater than the set value, then ignition is considered successful. This can improve the success rate of ignition detection.

[0080] This application also provides a parking heater, which includes a control module for executing the spark plug malfunction judgment method described in any one or more embodiments of this application.

[0081] In one embodiment, the parking heater further includes a heat exchanger, a first temperature sensor, and a second temperature sensor; The first temperature sensor is disposed on the surface of the heat exchanger to obtain the temperature of the heat exchanger; the second temperature sensor is disposed at the air inlet of the heat exchanger to obtain the ambient temperature.

[0082] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are generated entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0083] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0084] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining spark plug malfunction, applied to a parking heater, wherein the parking heater includes a spark plug, characterized in that, The method includes: When the parking heater is started, current is supplied to the spark plug to ignite the spark plug, and the first resistance value of the spark plug is detected; In response to the spark plug continuously operating for a first duration, the current is reduced, and a second resistance value of the spark plug is detected; By comparing the first resistance value and the second resistance value, it can be determined whether the spark plug has an ignition abnormality.

2. The spark plug malfunction judgment method according to claim 1, characterized in that, The step of determining whether the spark plug has an ignition abnormality by comparing the first resistance value and the second resistance value includes: Calculate the first absolute value of the difference between the first resistance value and the second resistance value; In response to the first absolute value being greater than a first threshold, it is determined that the spark plug has an ignition abnormality.

3. The spark plug malfunction judgment method according to claim 2, characterized in that, The parking heater further includes a heat exchanger, and the method further includes: In response to the first absolute value being less than or equal to a first threshold, the heat exchanger temperature and the ambient temperature are obtained; Calculate the second absolute value of the difference between the heat exchanger temperature and the ambient temperature; In response to the second absolute value being greater than the second threshold, it is determined that the spark plug is igniting normally.

4. The spark plug malfunction judgment method according to claim 3, characterized in that, Before determining that the spark plug ignition is normal in response to the second absolute value being greater than the second threshold, the method further includes: Determine the current operating level of the parking heater; Obtain the second threshold corresponding to the current operating gear.

5. The spark plug malfunction judgment method according to claim 3, characterized in that, The step of determining that the spark plug ignition is normal in response to the second absolute value being greater than the second threshold includes: In response to the second absolute value being greater than the second threshold, the change of the second absolute value within the first time period is determined; If the change in the second absolute value meets the first preset condition, it is determined that the spark plug is igniting normally.

6. The spark plug malfunction judgment method according to claim 5, characterized in that, The first preset condition includes at least one of the following: The trend is one of continuous increase; The change is greater than the third threshold; The rate of change is greater than the fourth threshold.

7. The spark plug malfunction judgment method according to claim 2, characterized in that, The step of determining that the spark plug has an ignition abnormality in response to the first absolute value being greater than the first threshold includes: In response to the first absolute value being greater than a first threshold, the second resistance value is detected multiple times within a second time period, and the corresponding first absolute value is calculated. In response to the fact that the change of the first absolute value within the second time period meets the second preset condition, it is determined that the spark plug has an ignition abnormality.

8. The spark plug malfunction judgment method according to claim 7, characterized in that, The second preset condition includes at least one of the following: The trend is one of continuous increase; The change exceeds the fifth threshold; The rate of change is greater than the sixth threshold.

9. The spark plug malfunction judgment method according to claim 1, characterized in that, The detection of the second resistance value of the spark plug includes: The second resistance value of the spark plug is detected according to a preset detection cycle or preset detection frequency.

10. A parking heater, characterized in that, The parking heater includes a control module, which is used to execute the spark plug malfunction judgment method according to any one of claims 1 to 9.

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