Engine fuel pump fault diagnosis method, device and equipment

Abstract

The invention relates to the technical field of fault diagnosis, and discloses an engine fuel pump fault diagnosis method, device and equipment, and the method comprises the steps: collecting the contact voltage, coil current and environment temperature and humidity parameters of a fuel pump relay, and obtaining P0233 fault circuit monitoring data; the fluctuation change of relay contact resistance in the P0233 fault circuit monitoring data is analyzed, a contact degradation early warning signal is obtained, voltage drop and current fluctuation at the moment of P0233 fault occurrence are monitored in real time, and fault transient electrical characteristics are obtained; the method comprises the following steps: constructing a fault feature fingerprint, matching the fault feature fingerprint with three root cause templates of contact ablation, coil aging and connector corrosion, obtaining a P0233 fault root cause type, generating a maintenance test parameter combination required by fault reproduction, reappearing a P0233 fault phenomenon, and obtaining a fault repair verification result. The consistency and reliability of diagnosis results are improved, and the one-time repair success rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of fault diagnosis, and in particular to a method, device and equipment for diagnosing engine fuel pump faults. Background Art

[0002] The intermittent fuel pump circuit fault P0233 is a technical challenge in automotive engine fault diagnosis. This fault exhibits significant environmental sensitivity and random recurrence, often manifesting only under specific temperature, humidity, and vibration conditions while appearing normal in conventional diagnostic environments. The mechanism of this intermittent fault is complex, involving multiple root causes such as relay contact aging, coil insulation deterioration, and connector corrosion. Furthermore, the fault symptoms are often extremely short-lived, making traditional static diagnostic methods difficult to identify potential defects before a fault occurs, and even more incapable of capturing the critical electrical signature information at the moment of fault onset. Summary of the Invention

[0003] The present invention provides an engine fuel pump fault diagnosis method, device and equipment, which establishes an active early warning mechanism for P0233 fault, improves the consistency and reliability of diagnosis results, and increases the one-time repair success rate.

[0004] A first aspect of the present invention provides an engine fuel pump fault diagnosis method, the engine fuel pump fault diagnosis method comprising: Collect the contact voltage, coil current, and ambient temperature and humidity parameters of the fuel pump relay to obtain P0233 fault circuit monitoring data; Analyzing the fluctuation of the relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal; Responding to the contact deterioration warning signal and monitoring the voltage drop and current fluctuation at the moment of P0233 fault occurrence in real time to obtain transient electrical characteristics of the fault; Based on the transient electrical characteristics of the fault, a fault feature fingerprint is constructed and matched with three root cause templates: contact ablation, coil aging, and connector corrosion, to obtain the root cause type of the P0233 fault; A maintenance test parameter combination required for fault reproduction is generated according to the P0233 fault root cause type, and the maintenance test parameter combination is executed to reproduce the P0233 fault phenomenon to obtain a fault repair verification result.

[0005] In combination with the first aspect, in a first implementation of the first aspect of the present invention, collecting the contact voltage, coil current, and ambient temperature and humidity parameters of the fuel pump relay to obtain P0233 fault circuit monitoring data includes: A fuel pump circuit test fixture is used to establish elastic contact connections with the relay contacts and coil terminals. An oscilloscope and multi-channel data recorder are used to perform impedance matching and noise filtering on the electrical signals to obtain the contact voltage and coil current. Monitor the temperature and relative humidity of the fuel pump working environment to obtain the ambient temperature and humidity parameters; The contact voltage, coil current and ambient temperature and humidity parameters are time stamp synchronized and data format standardized to obtain P0233 fault circuit monitoring data.

[0006] In combination with the first aspect, in a second implementation of the first aspect of the present invention, analyzing the fluctuation of the relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal includes: Performing Ohm's law calculation on the contact voltage and coil current in the P0233 fault circuit monitoring data to obtain a contact resistance value sequence; Performing sliding slice analysis on the contact resistance value sequence to obtain a contact resistance fluctuation characteristic data segment; Calculating the standard deviation and the coefficient of variation of the contact resistance fluctuation characteristic data segment, and extracting the frequency spectrum characteristic component of the resistance fluctuation by fast Fourier transform to obtain a contact degradation statistical parameter combination; The contact degradation statistical parameter combination is numerically compared with a standard deviation threshold and a coefficient of variation threshold to obtain a contact degradation early warning signal.

[0007] In combination with the first aspect, in a third implementation of the first aspect of the present invention, responding to the contact degradation warning signal and real-time monitoring of the voltage drop and current fluctuation at the moment of the P0233 fault to obtain the transient electrical characteristics of the fault includes: Receiving the contact degradation warning signal triggers the oscilloscope to switch to high-frequency sampling mode, and at the same time, expands the buffer depth of the multi-channel data recorder to a 30-second time window before and after the fault, to obtain intermittent fault capture configuration parameters; A voltage drop detection threshold and a current fluctuation detection threshold are set based on the intermittent fault capture configuration parameters, and data recording is automatically triggered when the relay contact voltage or coil current exceeds the detection threshold range to obtain a fault capture trigger condition; The fuel pump relay circuit is electrically monitored according to the fault capture triggering conditions. When the P0233 fault occurs, the drop process of the contact voltage and the transient fluctuation of the coil current are synchronously recorded to obtain the transient electrical characteristics of the fault.

[0008] In combination with the first aspect, in a fourth implementation of the first aspect of the present invention, constructing a fault feature fingerprint based on the transient electrical characteristics of the fault and matching it with three root cause templates of contact ablation, coil aging, and connector corrosion to obtain the root cause type of the P0233 fault includes: Performing peak detection and reference voltage comparison on the voltage waveform in the transient electrical characteristics of the fault, calculating the percentage deviation of the voltage drop depth from the rated voltage and the waveform distortion, and obtaining the voltage distortion amplitude; Decomposing the coil current signal in the transient electrical characteristics of the fault in the frequency domain and extracting the current harmonic components; Analyzing the time difference between the relay receiving the control signal and the contact being fully closed based on the timing data of the transient electrical characteristics of the fault, and measuring the coil excitation establishment time and the contact action response time to obtain the relay action delay; The voltage distortion amplitude, the current harmonic components, and the relay operation delay are constructed into a fault feature fingerprint. The similarity matching between the fault feature fingerprint and three root cause templates (contact erosion, coil aging, and connector corrosion) is calculated to obtain the root cause type of the P0233 fault.

[0009] In combination with the first aspect, in a fifth implementation of the first aspect of the present invention, the voltage distortion amplitude, the current harmonic components, and the relay operation delay are constructed into a fault feature fingerprint, and similarity matching between the fault feature fingerprint and three root cause templates of contact ablation, coil aging, and connector corrosion is calculated to obtain the root cause type of the P0233 fault, including: constructing the voltage distortion amplitude, the current harmonic component and the relay action delay into a fault feature fingerprint; Establish three root cause templates based on the preset fault root cause feature library: contact ablation, coil aging, and connector corrosion; The fault feature fingerprint is respectively calculated with the three root cause templates of contact ablation, coil aging, and connector corrosion to obtain three similarity distance values; The three similarity distance values are subjected to minimum value discrimination and threshold comparison, and the template with the minimum distance that is less than the preset matching threshold is selected as the root cause type of the P0233 fault.

[0010] In combination with the first aspect, in a sixth implementation of the first aspect of the present invention, generating a maintenance test parameter combination required for fault reproduction based on the P0233 fault root cause type, executing the maintenance test parameter combination to reproduce the P0233 fault phenomenon, and obtaining a fault repair verification result includes: According to the root cause type of the P0233 fault, a preset root cause environment association database is queried to map the contact ablation type to the high temperature and high humidity environmental condition, the coil aging type to the temperature cycle change condition, and the connector corrosion type to the humidity shock condition to obtain the environmental trigger condition; Numerical calculations are performed on the temperature range, humidity range, vibration frequency, and voltage fluctuation amplitude based on the environmental trigger conditions and fault occurrence history data to determine the minimum trigger value and maximum safety value boundary of each environmental parameter and obtain the electrical parameter range; The environmental trigger conditions and electrical parameter ranges are matched and durations are allocated according to the timing requirements for fault reproduction, and the environmental warm-up time, fault induction time, and state stabilization time are set to obtain a maintenance test parameter combination including a temperature setting value, a humidity setting value, a load current value, a test duration, and an operation step description; The maintenance test parameter combination is executed to drive the environmental simulation device to reproduce the P0233 fault phenomenon, verify the maintenance effect and confirm the fault elimination status, and obtain the fault repair verification result.

[0011] In combination with the first aspect, in a seventh implementation of the first aspect of the present invention, executing the maintenance test parameter combination to drive the environmental simulation device to reproduce the P0233 fault phenomenon, verifying the maintenance effect and confirming the fault elimination status, and obtaining the fault repair verification result includes: Inputting the maintenance test parameter combination into the temperature control module, humidity control module, and load simulation module in the environmental simulation device, automatically adjusting the ambient temperature, relative humidity, and fuel pump load current to the fault triggering condition according to a preset time sequence, and obtaining the fault reproduction environment state; Continuously electrically monitoring the fuel pump relay circuit based on the fault reproduction environment state to obtain an electrical characteristic record during the reproduction test process; Performing waveform similarity calculation and characteristic parameter comparison analysis on the electrical characteristic records during the re-test process and the transient electrical characteristics of the fault collected before the repair, to obtain fault characteristic difference data before and after the repair; The fault elimination judgment is performed based on the fault characteristic difference data before and after the repair. When the voltage distortion amplitude is reduced and the current harmonic distortion returns to the normal range, it is confirmed that the fault has been eliminated. Otherwise, it is determined that the repair is incomplete and needs to be reprocessed to obtain the fault repair verification result.

[0012] A second aspect of the present invention provides an engine fuel pump fault diagnosis device, the engine fuel pump fault diagnosis device comprising: The acquisition module is used to collect the contact voltage, coil current and ambient temperature and humidity parameters of the fuel pump relay to obtain the P0233 fault circuit monitoring data; An analysis module, configured to analyze the fluctuation of the relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal; A response module, configured to respond to the contact degradation warning signal and monitor in real time the voltage drop and current fluctuation at the moment of P0233 fault occurrence to obtain transient electrical characteristics of the fault; A matching module is used to construct a fault feature fingerprint based on the transient electrical characteristics of the fault and match it with three root cause templates of contact ablation, coil aging, and connector corrosion to obtain the root cause type of the P0233 fault; The repair verification module is used to generate a repair test parameter combination required for fault reproduction according to the P0233 fault root cause type, and execute the repair test parameter combination to reproduce the P0233 fault phenomenon to obtain a fault repair verification result.

[0013] A third aspect of the present invention provides an electronic device comprising: a memory and at least one processor, wherein the memory stores instructions; the at least one processor calls the instructions in the memory so that the electronic device executes the above-mentioned engine fuel pump fault diagnosis method.

[0014] Compared with existing technologies, this invention offers the following advantages: Through high-resolution resistance measurement technology and a sliding time window analysis method, it enables early identification of subtle signs of relay contact degradation, breaking through the limitations of traditional passive diagnosis and establishing an active early warning mechanism for P0233 faults. Triggered high-frequency sampling and multi-channel synchronous monitoring technology accurately capture the electrical characteristics of intermittent faults at the moment they occur, resolving the technical challenge of difficult fault reproduction. Through integrated environmental monitoring and machine learning algorithms, a fault trigger probability prediction model based on multiple environmental factors is constructed, enabling precise prediction of the fault occurrence time window. Innovative fault signature fingerprint construction and template matching techniques accurately distinguish between different root cause types, such as contact erosion, coil aging, and connector corrosion, providing precise location guidance for repairs. Portable fault reproduction testing and environmental simulation technology enable objective verification of repair effectiveness and quantitative confirmation of fault elimination status. A dynamic threshold adaptive adjustment mechanism automatically optimizes detection parameters based on vehicle characteristics, improving the consistency and reliability of diagnostic results and significantly increasing the first-time repair success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which the present invention can be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and objectives that can be achieved by the present invention.

[0017] Figure 1 1 is a flow chart of a method for diagnosing engine fuel pump faults provided by an embodiment of the present invention; Figure 2 1 is a schematic block diagram of the structure of an engine fuel pump fault diagnosis device provided by an embodiment of the present invention; Figure 3 It is a schematic block diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations. Figure 1 An embodiment of the engine fuel pump fault diagnosis method according to the present invention includes: Step 100: Collect the contact voltage, coil current, and ambient temperature and humidity parameters of the fuel pump relay to obtain P0233 fault circuit monitoring data; It is understandable that the execution subject of the present invention may be an engine fuel pump fault diagnosis device, or a terminal or a server, which is not limited here. The embodiment of the present invention is described by taking a server as the execution subject as an example.

[0022] Specifically, a fuel pump circuit test fixture is used. This fixture establishes stable and repeatable electrical contact between the relay's contact and coil terminals via an embedded elastic contact structure. Made of a highly elastic conductive alloy and equipped with a micro-positioning and locking mechanism, this structure effectively resists connection interference caused by vibration and displacement during vehicle operation, ensuring signal acquisition continuity and contact resistance consistency, thereby avoiding misjudgments due to poor contact. Sampling is performed using a high-precision automotive oscilloscope combined with a 16-channel multi-channel data recorder. The oscilloscope primarily acquires high-frequency voltage changes across the contacts, while the data recorder simultaneously records dynamic current changes at the coil terminals. An impedance matching network and low-pass filtering circuit are embedded in the signal acquisition chain to shield against external electromagnetic interference and reduce the impact of high-frequency noise, ensuring undistorted and non-distorted signal waveforms. While maintaining a sampling rate of at least 1MHz, contact voltage and coil current waveform curves with engineering usability are obtained. The environmental parameter collection system also features an integrated array of temperature and humidity sensors, boasting an accuracy of ±0.1°C for temperature and ±2%RH for relative humidity. These sensors are installed in close proximity to the relay and fuel pump electrical modules, providing real-time sensing of thermal and humidity changes in their microenvironment. Raw voltage, current, temperature, and humidity data are transmitted via the CAN bus to an embedded edge processing platform. Within this platform, each of these three data types is assigned high-precision timestamps according to a unified data structure template and synchronized within milliseconds. Linear interpolation and sliding alignment algorithms are used to eliminate timing deviations between different sampling modules. The data format is further standardized, including unit unification, sampling frequency alignment, data bit width normalization, and outlier removal. This ultimately creates a P0233 fault circuit monitoring dataset.

[0023] Step 200: Analyze the fluctuation of relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal; Specifically, based on the contact voltage and coil current signals in the P0233 fault circuit monitoring data, Ohm's law is used to calculate the resistance of each set of data points with aligned timestamps. That is, while maintaining unit consistency, the voltage value is divided by the current value at the corresponding moment to calculate the resistance value reflecting the dynamic conduction performance of the relay contact point by point, forming a contact resistance value sequence with a clear time series structure. A sliding slice analysis is performed on the resistance value sequence. By setting a fixed time window (e.g., 15 minutes) and performing sliding interception with a certain step size, local resistance fluctuation behavior is extracted within each time window to form multiple contact resistance fluctuation characteristic data segments with statistical integrity. These data segments retain the dynamic conduction characteristics of the contacts under different environments and working conditions. On this basis, statistical parameter calculations are performed on each data segment, including standard deviation calculation to measure the absolute discreteness of the resistance value, and coefficient of variation calculation to evaluate the relative amplitude of the resistance fluctuation relative to its average value. Frequency domain conversion is performed on the resistance data sequence through fast Fourier transform to extract the periodic characteristic components and high-frequency disturbance signals in the resistance fluctuation, thereby obtaining a contact degradation statistical parameter combination containing time domain and frequency domain information, which characterizes the conduction stability of the relay contacts per unit time and the existence of structural anomalies. This statistical parameter combination is compared with the judgment threshold, where the standard deviation threshold is used to identify situations where the absolute fluctuation is too large, and the coefficient of variation threshold is used to detect relatively unstable states. For example, when the standard deviation exceeds 0.002Ω and the coefficient of variation is greater than 3%, it is preliminarily determined that the contact has a deterioration trend. If a specific frequency mutation occurs in the spectrum, it can also be used as a basis for judging the early stage of contact surface ablation or oxidation. When any one or more parameters exceed their preset thresholds, a contact degradation warning signal is triggered.

[0024] Step 300: Respond to the contact degradation warning signal and monitor the voltage drop and current fluctuation at the moment of P0233 fault occurrence in real time to obtain transient electrical characteristics of the fault; Specifically, after detecting a contact degradation warning signal, the signal acquisition equipment undergoes dynamic parameter reconstruction. Upon receiving the warning signal, the oscilloscope automatically switches to high-frequency sampling mode, increasing its sampling rate from its normal low-frequency mode to a high-frequency mode of no less than 1 MHz to capture microsecond-level voltage transient dips. Simultaneously, the multi-channel data recorder simultaneously expands the depth of its circular buffer, extending the storable data time range by 30 seconds both forward and backward. This creates intermittent fault capture configuration parameters that cover both the fault precursor and subsequent response processes. Under these parameters, the system enters a highly sensitive state and sets voltage drop and current fluctuation detection thresholds based on historical electrical fluctuation characteristics. The voltage drop threshold establishes a tolerance boundary based on the steady-state voltage of the relay in the normal on-state, while the current fluctuation threshold sets a floating range based on the current stability coefficient of the coil in the normal excitation state. When the measured contact voltage drops sharply below the drop threshold or the coil current experiences a rapid perturbation above the fluctuation threshold, the fault capture trigger condition is automatically determined to be met, and all electrical signal data within 60 seconds before and after the current point in time is immediately frozen. On this basis, the electrical behavior of the fuel pump relay circuit is monitored in the full time domain. When the P0233 fault occurs, the oscilloscope and data recorder synchronously record the drop process of the relay contact voltage, including indicators such as waveform distortion slope, drop amplitude, and recovery delay. The transient fluctuation characteristics of the coil current include changes in fluctuation frequency, peak swing amplitude, and duration. These data constitute the transient electrical characteristics of the P0233 fault at the moment of occurrence.

[0025] Step 400: construct a fault feature fingerprint based on the transient electrical characteristics of the fault and match it with three root cause templates: contact ablation, coil aging, and connector corrosion to obtain the root cause type of the P0233 fault; Specifically, a structured analysis of the transient electrical characteristic data of the fault is performed. For the voltage signal, a waveform peak detection algorithm is used to perform a difference comparison with a reference voltage. The contact voltage at the lowest point during the fault and the steady-state value in the normal voltage range are extracted. The voltage drop depth is then calculated and normalized with the rated voltage to form a percentage deviation indicator. A waveform distortion analysis function is also used to assess the degree of deviation from an ideal square wave or sawtooth waveform, obtaining a voltage distortion amplitude parameter that reflects power supply stability and contact conduction quality. For the current signal, a fast Fourier transform algorithm is used to perform frequency domain decomposition of the transient current sequence, extracting the fundamental component and second to fifth harmonic components. Total harmonic distortion is then calculated to reflect the nonlinear response characteristics during coil excitation. These frequency domain characteristics vary significantly across different root cause types and are particularly sensitive to identifying non-steady-state magnetic field characteristics caused by coil aging and poor contact. After signal feature extraction in both voltage and current dimensions, quantitative modeling of the fault sequence behavior is performed. The relay's action delay is calculated by sampling the time difference between the moment the relay receives the control signal and the moment the contacts close. The delay is also calculated by measuring the excitation buildup time from coil energization to the completion of the magnetic field. The physical action response time required for the contact structure to close is then calculated to determine the relay's action delay. This delay can significantly increase with structural aging, coil demagnetization, or spring hysteresis. These three core parameters—voltage distortion amplitude, current harmonic components, and relay action delay—collectively constitute a multidimensional fault signature that reflects the nature of the fault. Once this fingerprint is obtained, a template matching algorithm is used to compare it with three pre-constructed typical root cause templates for similarity. The contact erosion template exhibits significant voltage waveform distortion, high current harmonic content, and minimal change in action delay. The coil aging template is characterized by prolonged excitation buildup time and increased total harmonic distortion. The connector corrosion template exhibits irregular voltage jumps, transient resistance increases, and significantly enhanced humidity response. The matching degree between fingerprints is calculated by integrating multiple indicators such as cosine similarity and Euclidean distance, and the matching template with the highest similarity is selected as the root cause type of the current fault to obtain the root cause type of the P0233 fault.

[0026] Step 500: Generate a maintenance test parameter combination required for fault reproduction based on the P0233 fault root cause type, execute the maintenance test parameter combination to reproduce the P0233 fault phenomenon, and obtain a fault repair verification result.

[0027] Specifically, based on the P0233 fault root cause type, a preset root cause environment association database is automatically queried. This database contains mapping relationships between various typical fault types and their inducing conditions. Among them, the contact ablation type is mapped to high temperature and high humidity environmental conditions, because its ablated surface is more prone to resistance mutation and surface ion migration behavior under high heat and humidity conditions; the coil aging type is mapped to temperature cycling conditions, because its insulation layer fatigue and magnetic flux drop are most obvious under drastic temperature fluctuations; the connector corrosion type is matched with humidity shock conditions, because moisture on the contact surface is prone to micro-electrochemical reactions and lead to contact instability. Through this mapping relationship, the environmental trigger conditions required for each fault root cause are extracted. Then, combined with the historical fault occurrence data stored in the system, a statistical regression analysis is performed on the above environmental factors to extract the typical change ranges of temperature, humidity, vibration frequency, and voltage fluctuation amplitude before and after the fault is induced. The minimum trigger value required for each parameter to trigger the fault and its maximum allowable safe value boundary are calculated to form a set of electrical parameter ranges. After obtaining the above trigger conditions and parameter boundaries, all parameters are paired and combined according to the timing control logic of the fault reproduction experiment, and the duration allocation is completed. This includes the environment preheating time setting to simulate the temperature and humidity gradual change process in natural working conditions; the fault induction time setting to control the starting time point of the electrical load and signal disturbance effect; the state stabilization time setting to ensure that the environmental parameters remain unchanged after the fault is stimulated to facilitate feature extraction. Finally, a maintenance test parameter combination including temperature setting value, humidity setting value, load current value, test duration and detailed description of the operation steps is integrated to generate. According to this parameter combination, the portable environmental simulation device is driven to perform simulation operations, and environmental working conditions, electrical loads, and interference signals are sequentially established to reproduce the P0233 fault process under controllable experimental conditions. After the fault phenomenon is successfully induced, the simulation data is recorded and compared with the original fault fingerprint for verification. At the same time, maintenance measures are implemented and the above test process is repeated. If the fault phenomenon no longer occurs under the full parameter reproduction conditions and the key electrical indicators return to the normal range, the repair is determined to be successful, and the fault repair verification result is output. The corresponding fingerprint status and repair success rate evaluation parameters in the fault database are updated to achieve the linkage between closed-loop verification and knowledge feedback mechanism.

[0028] In a specific embodiment, the process of executing step 100 may specifically include the following steps: A fuel pump circuit test fixture is used to establish elastic contact connections with the relay contacts and coil terminals. An oscilloscope and multi-channel data recorder are used to perform impedance matching and noise filtering on the electrical signals to obtain the contact voltage and coil current. Monitor the temperature and relative humidity of the fuel pump working environment to obtain the ambient temperature and humidity parameters; The contact voltage, coil current and ambient temperature and humidity parameters are time-stamped and aligned, and the data format is standardized to obtain the P0233 fault circuit monitoring data.

[0029] Specifically, a high-reliability elastic connection between the fuel pump circuit test fixture and the relay electrical node is achieved. The fixture uses an elastic contact terminal with micron-level contact surface deformation capability. Its conductive material is elastic copper alloy or gold-plated copper-titanium composite metal. Without destroying the original circuit structure, non-invasive detection of the relay contact voltage terminal and the current path at both ends of the coil is achieved. A micro-positioning support spring system and a vibration damping module are installed inside the fixture structure to ensure that the contact is not loose, drifting, or broken within the vehicle's operating vibration frequency range, thereby providing a stable, low-contact impedance signal coupling path, and cooperating with multi-size adjustable contact surface adapters to support rapid connection adaptation of multiple models of relay structures. The output end of the fixture is connected to a high-frequency automotive oscilloscope and a multi-channel data recorder via a dedicated shielded transmission cable. The oscilloscope is used to capture the high-frequency dynamically changing contact voltage signal, while the data recorder achieves high-time precision tracking and acquisition of coil current changes. At the same time, both are connected to a front-end buffer device composed of an input impedance automatic matching module to maintain the impedance closure relationship between the signal source and the acquisition device. On this basis, a bandpass filter group and an adaptive filtering algorithm module are deployed simultaneously. Signal purification processing is performed through low-pass, band-stop and pseudo-random interference identification mechanisms to effectively suppress non-correlated electrical interference components caused by ignition pulses, CAN bus interference and mechanical contact noise, ensuring that the collected contact voltage and coil current data have high fidelity, high resolution and anti-interference capabilities.While collecting electrical parameters, the system is also deployed with an environmental parameter perception module, which consists of multiple integrated temperature and humidity digital sensors. Each group of sensors is equipped with an independent address code and time synchronization control interface. The temperature measurement accuracy reaches ±0.1°C, and the humidity measurement error is controlled within ±2%RH. The sensor layout is preferably close to the outer wall of the fuel pump cabin or relay housing, and micro-ventilation holes are set to balance the temperature and humidity exchange efficiency between the detection area and the outside world, so as to perceive the changing trend of the thermal and humidity environment in the working space of the fuel pump in real time. The module supports fast-response measurement cycle setting, and its sampling period is no more than 500ms. After digital pre-processing, the data is uploaded to the edge computing control unit through the I2C interface in a standard data frame format, and enters the unified time axis processing process together with the voltage and current data. High-precision is used in this process. The internal clock of the system is used as a unified reference to add a unified timestamp to all data from the oscilloscope, data logger, and temperature and humidity module. A multi-source data alignment algorithm is used to synchronize sampling points from different sources within the millisecond range to avoid data time inconsistencies caused by sampling start offset or interruption interference. After time alignment, a standardized format conversion module is used to convert all data items into a unified unit, format, and data length structure. Missing values, outliers, or sampling discontinuities are interpolated and statistically supplemented. Finally, a P0233 fault circuit monitoring dataset is generated. This dataset contains the full time domain waveform data of the contact voltage, the dynamic response curve of the coil current, and the changing trend sequence of the ambient temperature and humidity. It also integrates the time position information and source channel identification information of each data point.

[0030] In a specific embodiment, the process of executing step 200 may specifically include the following steps: Apply Ohm's law to the contact voltage and coil current in the P0233 fault circuit monitoring data to obtain a sequence of contact resistance values. Perform sliding slice analysis on the contact resistance value sequence to obtain the contact resistance fluctuation characteristic data segment; The standard deviation and coefficient of variation of the contact resistance fluctuation characteristic data segment are calculated. At the same time, the spectrum characteristic components of the resistance fluctuation are extracted through fast Fourier transform to obtain the contact degradation statistical parameter combination; The contact degradation statistical parameter combination is numerically compared with the standard deviation threshold and the coefficient of variation threshold to obtain the contact degradation early warning signal.

[0031] Specifically, structured calculations are performed on the P0233 fault circuit monitoring data. The system uses the contact voltage and coil current values corresponding to each time point as input pairs, and uses Ohm's law, which states that resistance equals voltage divided by current, to perform point-by-point calculations. The contact voltages of all valid sample points in the entire data sequence are divided by their corresponding coil currents to form a time-ordered set of resistance calculation results. This sequence is the contact resistance value sequence that reflects the real-time conduction state of the relay contacts. During the calculation process, sampling points with zero or near-zero current are filtered and marked to avoid numerical divergence or invalid points contaminating the entire data set due to abnormal divisors. Logical markers are also added to intervals where the resistance value changes abnormally. The contact resistance numerical sequence is subjected to sliding slice analysis, and the resistance sequence is extracted in sliding segments on the time axis with fixed window length and step length parameters. The window length is set to 15 minutes, and the step length is set between 30 seconds and 1 minute. The number of samples contained in each slice is determined according to the sampling frequency, and the sample time continuity is maintained within each slice. In this way, the system can extract local change trends from long-term data and form independent but comparable contact resistance fluctuation characteristic data segments in multiple time periods. Each data segment is assigned a unique time label and source information. A statistical feature extraction operation is performed within each data segment, and the standard deviation value of all resistance samples in the segment is calculated as an indicator reflecting the absolute degree of fluctuation. The coefficient of variation, which is the ratio of the standard deviation to the mean value, is then calculated to reflect the relative intensity of the fluctuation. This indicator has high sensitivity to non-uniform changes and low-value mutations. The resistance data segment is input into the frequency domain transformation module, and the time series signal is converted into a frequency domain signal using fast Fourier transform. The spectral characteristics such as its main frequency components, power spectral density distribution and high-frequency energy concentration are extracted to obtain a multidimensional frequency domain indicator reflecting the periodicity, impact and stability of contact resistance fluctuations. These statistical parameters and spectral characteristics constitute a contact degradation statistical parameter combination. Each combination includes sub-parameters such as standard deviation value, coefficient of variation value, main frequency component, harmonic amplitude and spectral energy concentration ratio, and is uniformly represented by a feature vector structure. The contact degradation statistical parameter combinations are compared one by one with the contact degradation judgment thresholds, where the standard deviation threshold is set to 0.002 ohms and the coefficient of variation threshold is set to 3%. If any indicator in the parameter combination exceeds its corresponding threshold, the system preliminarily determines that there is a degradation trend. If multiple indicators exceed the limit at the same time, the judgment level is further increased, and the three risk levels of red, yellow, and green are visually graded. At the same time, the judgment results are pushed to the fault prediction module and the upper control platform in the form of early warning signals.

[0032] In this embodiment, obtaining the contact degradation warning signal also includes the step of establishing a P0233 fault trigger probability prediction model based on multiple environmental factors: the contact degradation warning signal is correlated with the real-time collected temperature cycle, vibration shock, humidity change, voltage fluctuation, load change, start-stop frequency, operating time, fuel quality, atmospheric pressure, electromagnetic interference, road bumps, driving habits, maintenance history, and vehicle age to obtain an environmental factor data set; the weight coefficient of each factor in the environmental factor data set is calculated through historical fault data training, wherein the weight of the temperature cycle factor is set to 0.18, the weight of the vibration shock factor is set to 0.15, and the weight of the humidity change factor is set to 0.12. The weights of the remaining factors are dynamically allocated according to the fault correlation to obtain a weighted environmental factor parameter combination; the weighted environmental factor parameter combination is input into the embedded edge computing processor for random forest algorithm processing, and the weighted environmental factor parameter combination is constructed by An ensemble learning model of 500 decision trees performs voting on the probability of the P0233 fault to obtain a fault probability assessment value. A time series analysis is performed based on the fault probability assessment value and the changing trend of current environmental conditions. A probability threshold judgment and time window partitioning algorithm are used to calculate the time interval within which the P0233 fault will occur within the next 72 hours, resulting in a fault time window prediction result. A time range with a prediction accuracy of ±6 hours is set based on the fault time window prediction result. When the fault probability exceeds the preset threshold and the prediction time window is narrowed to within 24 hours, a trigger signal indicating an impending fault is generated, resulting in a precise fault prediction trigger condition. The precise fault prediction trigger condition is logically integrated with the contact degradation warning signal, with the prediction result updated every 30 minutes and the monitoring sensitivity dynamically adjusted. When both conditions are met, a high-priority fault capture preparation state is initiated, resulting in a fault warning signal.

[0033] In a specific embodiment, the process of executing step 300 may specifically include the following steps: Receiving the contact degradation warning signal triggers the oscilloscope to switch to high-frequency sampling mode, and at the same time, the buffer depth of the multi-channel data recorder is extended to a 30-second time window before and after the fault to obtain the intermittent fault capture configuration parameters; The voltage drop detection threshold and current fluctuation detection threshold are set based on the intermittent fault capture configuration parameters. When the relay contact voltage or coil current exceeds the detection threshold range, data recording is automatically triggered to obtain the fault capture trigger condition; The fuel pump relay circuit is electrically monitored according to the fault capture trigger conditions. When the P0233 fault occurs, the contact voltage drop process and the transient fluctuation of the coil current are synchronously recorded to obtain the transient electrical characteristics of the fault.

[0034] Specifically, the contact degradation warning signal is used as the dynamic starting condition for the entire fault capture mechanism. When the system detects that the contact state has entered the critical degradation range based on the previous contact resistance fluctuation analysis, and the degradation level reaches the preset risk threshold, it sends a configuration change command to the oscilloscope and data recorder through a control instruction. The channel of the oscilloscope originally in low-frequency monitoring mode will switch to high-frequency sampling mode, and its sampling frequency will be increased from the default 10kHz to no less than 1MHz, capturing high-frequency details in voltage distortion with microsecond time accuracy. At the same time, the multi-channel data recorder adjusts the cache strategy, expanding the default ring cache capacity to support a bidirectional buffer structure that supports recording data 30 seconds before and 30 seconds after the fault. The data is automatically archived in timestamp order to ensure that data integrity is preserved in both the warning stage before the fault and the recovery stage after the fault. In this process, the oscilloscope sampling mode and data recording cache strategy automatically generated by the system are uniformly packaged as intermittent fault capture configuration parameters and uploaded to the edge control unit for linkage logic control. Based on the configuration parameters, the system adaptively calculates the voltage drop detection threshold and the current fluctuation detection threshold under the current vehicle operating conditions, power supply status and electromagnetic environment. The voltage drop detection threshold is set to the condition that the normal contact voltage drops by more than 20% of the rated voltage and the duration is greater than 2ms. The current fluctuation detection threshold is set to the condition that the excitation current has an amplitude disturbance of more than ±15% or the fluctuation frequency is higher than 200Hz. The threshold is dynamically adjusted according to the actual relay load characteristics and historical fault statistics, and is jointly analyzed with the current acquisition system noise level to eliminate the possibility of misjudgment. When any real-time sampling data during system operation exceeds any of the above threshold ranges, the fault capture trigger condition is triggered. At this time, the system locks the data of the relevant channels, freezes all contact voltage and coil current data within 30 seconds before and after the trigger point, and sends them to the tag buffer area, with the trigger event as the center. High-precision event tags are generated, and the system enters a highly sensitive fault monitoring state, continuously electrically monitoring the fuel pump relay circuit to capture the fault evolution process. At the moment the P0233 fault actually occurs, the voltage of the relay contacts drops sharply due to poor contact or arc breakdown, causing nonlinear collapse, sawtooth distortion, or instantaneous zero jumps in the voltage waveform. The coil current, on the other hand, experiences peak surges, harmonic distortion, or frequency jumps due to loop incompleteness, electromagnetic saturation, or intermittent magnetic circuits. The system records these dynamic changes through a high-frequency sampling mechanism, including voltage signal characteristics such as the contact voltage drop start time, drop duration, recovery slope, waveform disturbance frequency, and return to steady-state time. Current characteristic parameters such as the coil current's maximum disturbance amplitude, harmonic energy distribution, fluctuation frequency variation trajectory, and energy concentration interval are also recorded, ultimately forming a fault transient electrical characteristic dataset.

[0035] In a specific embodiment, the process of executing step 400 may specifically include the following steps: Perform peak detection and reference voltage comparison on the voltage waveform in the transient electrical characteristics of the fault, calculate the percentage deviation of the voltage drop depth from the rated voltage and the waveform distortion, and obtain the voltage distortion amplitude; Decompose the coil current signal in the fault transient electrical characteristics in the frequency domain and extract the current harmonic components; Based on the timing data of the transient electrical characteristics of the fault, the time difference from the relay receiving the control signal to the contact fully closing is analyzed. At the same time, the coil excitation buildup time and the contact action response time are measured to obtain the relay action delay. The voltage distortion amplitude, current harmonic components, and relay operation delay are constructed as a fault feature fingerprint. The similarity between the fault feature fingerprint and three root cause templates (contact ablation, coil aging, and connector corrosion) is calculated to obtain the root cause type of the P0233 fault.

[0036] Specifically, the contact voltage waveform recorded in the transient electrical characteristics of the fault is subjected to peak detection processing. This process sets a reference voltage window and selects the voltage in the stable working state before the fault as the reference baseline. The system uses a sliding extreme value extraction algorithm to scan the entire waveform data segment, identify the deepest negative offset point and the peak that rebounds after the drop, and then calculates the percentage deviation of the voltage drop depth by dividing the difference between the lowest voltage value and the reference voltage value by the rated voltage value. At the same time, the Fourier reconstruction and ideal model comparison method are used to calculate the nonlinear distortion index of the waveform in the continuous segment of the waveform. The comprehensive waveform distortion coefficient is obtained by combining the amplitude, phase and stability characteristics, which is then defined as the voltage distortion amplitude and recorded in a structured data format. The coil current waveform data from the fault transient electrical characteristics is transformed into the frequency domain. This part uses the fast Fourier transform algorithm to perform discrete spectrum expansion on the sampled time series. The second to fifth harmonic frequencies are identified by extracting the frequency domain energy concentration interval and using the harmonic peak recognition mechanism. The amplitude intensity corresponding to each harmonic frequency is normalized and calibrated before being extracted as a current harmonic component feature group. The total harmonic distortion is also calculated simultaneously as a quantitative indicator for determining coil hysteresis or conduction instability. Based on the extraction of the voltage and current signal features, the system reads the time series data tags in the fault record. Combining the control signal injection time and the rising edge boundary of the relay contact closure completion signal, the delay between the control trigger and the physical action is calculated. This value is the relay action response delay. The excitation establishment time is defined as the period from coil energization to the stabilization of the excitation current, and the contact action response time is defined as the interval from the completion of excitation establishment to the return of the contact conduction voltage to normal. These three time delays constitute the components of the relay action delay, which are used to characterize the linkage delay of the internal magnetic circuit, electrical path, and mechanical action of the mechanism. All of the aforementioned characteristic values—voltage distortion amplitude, current harmonic components, and relay operation delay—are combined into a unified feature vector structure to form a fault signature fingerprint. This fingerprint is represented in a vectorized multidimensional feature space, where each dimension has a clear physical definition and numerical boundaries. This fingerprint is then compared against a pre-set root cause template fingerprint library in the system. This fingerprint library contains three typical root cause feature templates trained by classifying a large number of historical fault samples. The contact erosion template exhibits significant voltage distortion amplitude, high current harmonic distribution, and minimal changes in relay operation delay. The coil aging template exhibits a sharp increase in harmonic content, significantly prolonged excitation time, and minimal voltage drop. The connector corrosion template exhibits short voltage jumps, moderate harmonic component fluctuations, and irregular operation delay. By calculating similarity metrics (e.g., Euclidean distance, cosine similarity, and correlation coefficient) between the current fault fingerprint and these three root cause templates in feature vector space, the degree of match between each template and the current fault is determined. The template with the greatest similarity is selected as the root cause type for the current P0233 fault.

[0037] In a specific embodiment, the process of executing the step of constructing the voltage distortion amplitude, current harmonic components, and relay operation delay into a fault feature fingerprint, and calculating the similarity matching between the fault feature fingerprint and three root cause templates of contact ablation, coil aging, and connector corrosion to obtain the root cause type of the P0233 fault can specifically include the following steps: The voltage distortion amplitude, current harmonic components and relay operation delay are constructed as fault feature fingerprints; Establish three root cause templates based on the preset fault root cause feature library: contact ablation, coil aging, and connector corrosion; The fault feature fingerprint is calculated with the three root cause templates of contact ablation, coil aging, and connector corrosion respectively, and three similarity distance values are obtained; Perform minimum value discrimination and threshold comparison on the three similarity distance values, and select the template with the smallest distance that is smaller than the preset matching threshold as the root cause type of the P0233 fault.

[0038] Specifically, based on the fault parameters output by the standardized feature extraction module, the voltage distortion amplitude, current harmonic components, and relay operation delay are respectively used as independent feature dimensions, numerically normalized using a unified physical quantity measurement unit, and constructed into a feature structure in the form of a three-dimensional vector according to a fixed arrangement order to form a fault feature fingerprint. The voltage distortion amplitude is used to reflect the transient voltage response anomaly caused by unstable relay contact conduction in the power supply system. The current harmonic components characterize the degree of magnetic field coupling nonlinearity of the coil system during the fault excitation process. The relay operation delay reflects the dynamic response efficiency of the entire electromechanical linkage mechanism under signal control. The combination of these three features fully describes the electrical behavior profile and timing variation pattern when the P0233 fault occurs. The system calls up a preset fault root cause feature library, which is trained and summarized by a large amount of historical fault data and its stability has been verified by multiple experiments. It contains three types of typical root cause templates, namely contact erosion template, coil aging template and connector corrosion template. Each template is composed of a three-dimensional feature vector, which gives standard values or reference values in the three indicator dimensions of voltage distortion amplitude, current harmonic component and relay action delay. Among them, the contact erosion template characteristics are mainly manifested in a significantly large voltage distortion amplitude, medium current harmonic disturbance and small change in action delay. The coil aging template characteristics are manifested in a sharp increase in current harmonic content, a significant extension of action delay and an insignificant voltage distortion amplitude. The connector corrosion template is accompanied by medium and high amplitude voltage mutations, irregular fluctuations of low-frequency harmonics and intermittent and inconsistent action delays. By arranging these three types of templates in the template space to form a standard reference set, the system compares the current fault feature fingerprints one by one. During the comparison process, the system uses Euclidean distance as the main algorithm for similarity judgment. According to the definition formula of Euclidean distance, the geometric distance between the current fault feature fingerprint and the three types of templates in the three-dimensional feature space is calculated respectively. This calculation process involves squaring the difference of the three feature indicators in their respective dimensions, summing them up, and then taking the square root. The generated result represents the distance between the current fault state and the template at the comprehensive feature level. The smaller the value, the higher the similarity between the fault fingerprint and the corresponding template. Therefore, the system defines the calculation results as D1, D2, and D3, respectively, where D1 represents the Euclidean distance between the current fault and the contact ablation template, D2 represents the distance to the coil aging template, and D3 represents the distance to the connector corrosion template. After completing the three distance calculations, the system performs minimum value judgment on the three. By comparing the minimum value positions of D1, D2, and D3, it is preliminarily determined which type of root cause pattern the current fault is closer to.To avoid misjudgments due to abnormal data fluctuations or overlapping statistical distributions, a threshold discrimination mechanism is introduced before the final match. That is, after the minimum value discrimination is completed, the minimum Euclidean distance value is compared with the preset matching threshold T. A match is considered successful only when the minimum distance value is less than the threshold T. The system outputs the template with the minimum distance and that meets the threshold condition as the root cause type of the current P0233 fault. The threshold T is set based on empirical data analysis and feature space clustering density, with a value range of 0.15 to 0.25. Its purpose is to provide fault tolerance for fuzzy boundaries or atypical overlapping states. If all three distance values are greater than the matching threshold, the system marks the fault as an unknown type or a composite type, triggering the deep learning model to perform a secondary match or start the manual review mechanism, and outputting a low confidence prompt.

[0039] Among them, after obtaining the voltage distortion amplitude, current harmonic components and relay action delay and before constructing the fault feature fingerprint, it also includes the steps of deeply analyzing and enhancing the fault features based on the double-layer agent model: inputting the voltage distortion amplitude, current harmonic components and relay action delay into the first-layer feature agent model, and performing dimensionality reduction processing and noise filtering on the original features through the principal component analysis algorithm, while using the wavelet transform technology to extract the time-frequency domain detail features of the fault signal to obtain the pre-processed basic feature vector; establishing an adaptive feature selection mechanism for the first-layer agent based on the basic feature vector, identifying the feature components with the highest contribution to the P0233 fault diagnosis through mutual information calculation and correlation analysis, eliminating redundant features and retaining key feature dimensions, and obtaining the optimized core feature set; passing the core feature set to the second-layer deep analysis agent model, and using the deep neural network structure to select the best feature set. The structure performs nonlinear mapping and feature fusion processing on the features, and learns the complex correlation between fault features through a multi-layer perceptron network to obtain a high-dimensional abstract feature representation; a feature enhancement mechanism is established in the second-layer agent model, and data enhancement of rare fault modes is performed through the adversarial generative network technology. At the same time, the attention mechanism is used to highlight the weight distribution of key fault features to obtain an enhanced fault feature vector; a feedback optimization mechanism is constructed between the two-layer agent models, and the analysis results of the second-layer agent update the feature selection strategy of the first-layer agent through gradient backpropagation, forming an iteratively optimized closed-loop learning system, and obtaining adaptively optimized feature extraction parameters; the enhanced fault feature vector is weightedly fused with the original fault feature, and the final fault feature weight distribution is determined through confidence evaluation and uncertainty quantification methods to obtain a comprehensive fault feature fingerprint optimized by the two-layer agent model.

[0040] In a specific embodiment, the process of executing step 500 may specifically include the following steps: Based on the P0233 fault root cause type, the preset root cause environment association database is queried. The contact ablation type is mapped to the high temperature and high humidity environmental condition, the coil aging type is mapped to the temperature cycle change condition, and the connector corrosion type is mapped to the humidity shock condition to obtain the environmental trigger condition. Based on environmental trigger conditions and historical fault data, numerical calculations are performed on the temperature range, humidity range, vibration frequency, and voltage fluctuation amplitude to determine the minimum trigger value and maximum safety value boundary of each environmental parameter and obtain the electrical parameter range. The environmental trigger conditions and electrical parameter ranges are matched and durations are allocated according to the timing requirements for fault reproduction. At the same time, the environmental warm-up time, fault induction time, and state stabilization time are set to obtain a maintenance test parameter combination including temperature setting value, humidity setting value, load current value, test duration, and operation step description; Execute the maintenance test parameter combination to drive the environmental simulation device to reproduce the P0233 fault phenomenon, verify the maintenance effect and confirm the fault elimination status, and obtain the fault repair verification result.

[0041] Specifically, the P0233 fault root cause type is entered into a preset root cause environment association database for conditional query. This database is a structured mapping table of root causes and environmental inducements, established based on a large amount of historical experimental test data and engineering statistical samples. A stable mapping logical relationship is established between typical fault types and their high-frequency inducement environments through multi-variable analysis methods. In this mapping relationship, contact ablation-type faults are most likely to be triggered in high temperature and high humidity environments due to the continuous burning of surface arcs and the increased metal oxidation rate. Therefore, they are mapped to "high temperature and high humidity" as the main environmental condition. Coil aging-type faults are related to long-term temperature cycling changes. Due to the repeated alternation of thermal expansion and cooling contraction of insulating materials, the dielectric performance deteriorates. Therefore, they are mapped to the "temperature cycle fluctuation" condition. Connector corrosion-type faults are prone to condensation and ion migration under humidity shock, resulting in a sharp increase in contact resistance. Therefore, they are mapped to the "humidity pulse change" environment. After matching, these three types of environmental inducement factors form an environmental trigger condition dataset. After obtaining clear environmental trigger conditions, the system further retrieves historical P0233 fault cases and experimental reproduction sample data. Using multivariate regression modeling and minimum excitation parameter analysis techniques, it calculates the minimum trigger value and maximum safety value range for key physical trigger parameters such as temperature, humidity, vibration frequency, and voltage fluctuation amplitude. The minimum trigger value refers to the lowest environmental or electrical parameter value that effectively triggers the target fault under the currently identified root cause type. For example, for the contact burnout root cause, the analysis shows that the minimum trigger temperature is approximately 85°C and the minimum relative humidity is 80% RH. The maximum safety value is the upper limit that maintains system operational integrity without causing systemic damage, such as temperature not exceeding 110°C, humidity not exceeding 95% RH, vibration frequency not exceeding 50Hz, and voltage drop not exceeding 30% of the rated value. All of these environmental and electrical trigger indicators are determined through statistical feature extraction, parameter distribution analysis, and failure probability calculation, and organized into a vector structure to form the electrical parameter range.Based on the logical flow requirements of fault reproduction, environmental trigger conditions are sequentially paired with electrical parameter ranges. The specific application sequence and duration are designed in conjunction with the experimental platform's response characteristics. Based on this, the system establishes a three-stage test time structure. This includes an environmental warm-up time, which slowly adjusts the target environment to the set value and eliminates gradient effects. This timeframe ranges from 5 to 10 minutes. The fault induction time is the core phase from the start of application of the electrical load, voltage disturbance, or humidity pulse to the onset of the fault. During this period, all induced parameters are maintained above the minimum excitation value but not exceeding the maximum safe value, maintaining a stable duration of 30 seconds to 2 minutes. The state stabilization time, which lasts 1 to 3 minutes, is used to maintain the full development of the fault phenomenon and ensure stable data recording by each sensor. This three-stage timeframe constitutes a complete reproduction cycle. This cycle, combined with the parameter settings, is combined into a standardized maintenance test parameter set, which includes elements such as temperature setpoint, humidity setpoint, load current value, supply voltage fluctuation amplitude, vibration frequency, application duration, and fault identification target. This parameter set is accompanied by detailed operational steps and intermediate state judgment nodes. This parameter set format is a JSON structure or PLC control instruction set, which can be directly read and executed by the automated test system. After the parameter combination is generated, the system activates the environmental simulation device and sequentially performs environmental conditioning, signal injection, and load simulation according to the combined parameters. The entire fault reproduction process is completed through the temperature chamber, humidity control system, programmable power supply, and electronic load module. During operation, the system collects all sensor data in real time and determines the occurrence of the fault. The system determines that the reproduction is successful when the P0233 fault code or its electrical signature fingerprint reappears. The system then records the environmental context and operation trajectory of the successful reproduction and immediately enters the repair verification process. During this process, if the repair operation is immediately performed after the fault reproduction is completed, the same test parameter combination is applied again to re-apply the same environmental and electrical stimulus conditions. If the system does not trigger the P0233 fault code again and the voltage and current behavior are stable, the repair is considered successful. The system outputs the fault repair verification result and updates the equipment health status mark and repair success rate indicator. The test data, parameter combination, and final judgment result are archived in the equipment operation and maintenance database for the next round of prediction model training and environmental sensitivity correction.

[0042] In a specific embodiment, the process of executing the step of executing the maintenance test parameter combination to drive the environmental simulation device to reproduce the P0233 fault phenomenon, verifying the maintenance effect and confirming the fault elimination status, and obtaining the fault repair verification result can specifically include the following steps: The maintenance test parameter combination is input into the temperature control module, humidity control module and load simulation module in the environmental simulation device, and the ambient temperature, relative humidity and fuel pump load current are automatically adjusted to the fault triggering conditions according to a preset time sequence to obtain the fault reproduction environment state; Continuously monitor the fuel pump relay circuit based on the fault reproduction environment to obtain electrical characteristics records during the reproduction test process; The electrical characteristics recorded during the re-test process are compared with the transient electrical characteristics of the fault collected before the repair to calculate the waveform similarity and compare the characteristic parameters to obtain the difference data of the fault characteristics before and after the repair. The fault elimination judgment is made based on the difference data of the fault characteristics before and after the repair. When the voltage distortion amplitude is reduced and the current harmonic distortion returns to the normal range, it is confirmed that the fault has been eliminated. Otherwise, it is determined that the repair is incomplete and needs to be reprocessed to obtain the fault repair verification result.

[0043] Specifically, the maintenance test parameter combination is input into the control interface of the environmental simulation device as a control instruction set. The instruction set is distributed to each submodule through a standard communication protocol, including the temperature control module, the humidity control module and the load simulation module. The system starts the automatic adjustment process according to the preset time sequence under the high-precision closed-loop control mechanism based on the temperature target value, humidity target value and load current value set in the instruction, and the time node information in the parameter. The temperature control module adjusts the heat source output according to the temperature setting value, and adopts the PID temperature control algorithm to maintain the internal temperature of the temperature control chamber stable operation with an accuracy of ±0.5°C, while setting the heating rate and steady-state holding time; humidity The control module adjusts the relative humidity to the set target through an electronic humidity generator, and adopts a linkage method of micro-mist humidification and dehumidification to control the humidity change rate and maintain ±2%RH accuracy. The load simulation module simulates the corresponding load current variation characteristics during the operation of the fuel pump by programming an electronic load, adjusting the load current to a set value range between 0.1A and 20A, and supporting complex injection waveforms such as load steps, current ramp-up, and periodic disturbances. The above three types of parameters are executed in parallel in a time series in the environmental simulation device. When the temperature, humidity, and current all enter the set fault trigger range and reach the set stability holding time, it is considered that the fault reproduction environment state has been established. While maintaining this state, the system performs full-channel continuous electrical monitoring of the fuel pump relay circuit, using a high-frequency oscilloscope to collect the voltage waveform at both ends of the relay contacts. At the same time, a multi-channel current acquisition system is used to record the dynamic response process of the coil excitation current in real time. All electrical data are synchronously timestamped and written into the reproducible test data channel. At the same time, the system performs real-time noise filtering and frequency domain analysis operations to ensure the validity and comparability of the data. At this stage, the system focuses on whether the voltage waveform shows distortion behavior, whether the waveform drop amplitude and duration are consistent with the fault, and whether the current is accompanied by abnormal characteristics such as nonlinear disturbances, harmonic enhancement or frequency jitter. After the reproduction test phase is completed, the system will enter the data comparison and analysis process, call the fault transient electrical characteristics collected before maintenance as the baseline data sample, and perform waveform alignment and feature extraction operations on the electrical characteristics collected in the reproduction test. The DTW (dynamic time warping) algorithm is used to align and calculate the similarity score of the two sets of voltage waveform curves, and extract key points such as the drop starting point, the maximum waveform distortion point and the recovery stable boundary point. At the same time, the current waveform is decomposed in the frequency domain, its harmonic components are extracted and the changes in the harmonic amplitudes of each order are compared, thereby forming a characteristic parameter difference vector before and after maintenance. This vector structure includes multi-dimensional indicators such as the change value of the voltage distortion amplitude, the voltage recovery speed change ratio, the change value of the current total harmonic distortion, the frequency shift value of the harmonic main component and the change in the response time delay.The system quantitatively evaluates and makes decisions based on the aforementioned characteristic difference values. The judgment logic follows the following criteria: If the voltage distortion amplitude decreases by more than 50% compared to pre-repair levels and the waveform becomes linear, the voltage waveform returns to within ±10% of the rated value, and the total current harmonic distortion returns to below the system-specified stable operation threshold (less than 5%), while the amplitudes of all harmonics are lower than the upper limit of the historical normal range and the relay operation delay returns to the normal range (e.g., between 10ms and 15ms), the system determines that the fault has been effectively repaired and outputs a fault elimination conclusion. The system then records the repair parameter combination and the final repair status as a successful sample and writes them into the fault database. If any of the above indicators fail to meet the repair judgment criteria—for example, if the voltage distortion amplitude remains above the reference standard, the current harmonic distortion does not significantly decrease, or the operation delay does not improve—the system determines that the current repair operation has not completely resolved the root cause and outputs a judgment of incomplete repair. It also marks the current parameter combination as partially failed and prompts a re-evaluation of the root cause identification or operation plan.

[0044] The above describes the engine fuel pump fault diagnosis method according to the embodiment of the present invention. The following describes the engine fuel pump fault diagnosis device according to the embodiment of the present invention. Figure 2 In one embodiment of the present invention, an engine fuel pump fault diagnosis device includes: The acquisition module 11 is used to collect the contact voltage, coil current and ambient temperature and humidity parameters of the fuel pump relay to obtain the P0233 fault circuit monitoring data; Analysis module 12, used to analyze the fluctuation of relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal; The response module 13 is used to respond to the contact degradation warning signal and monitor the voltage drop and current fluctuation at the moment of P0233 fault in real time to obtain the transient electrical characteristics of the fault; Matching module 14 is used to construct a fault feature fingerprint based on the transient electrical characteristics of the fault and match it with three root cause templates: contact ablation, coil aging, and connector corrosion, to obtain the root cause type of the P0233 fault; The repair verification module 15 is used to generate a repair test parameter combination required for fault reproduction according to the root cause type of the P0233 fault, and execute the repair test parameter combination to reproduce the P0233 fault phenomenon to obtain a fault repair verification result.

[0045] Through the collaborative efforts of these components, high-resolution resistance measurement technology and sliding time window analysis methods can detect the subtle resistance fluctuations of relay contacts under normal operating conditions, identifying early signs of contact degradation. This overcomes the technical limitations of traditional passive diagnosis and provides early warning before a fault fully manifests. Triggered high-frequency sampling technology and multi-channel synchronous monitoring methods accurately capture the voltage drop and current fluctuation characteristics at the moment of the P0233 fault, addressing the technical challenge of capturing intermittent faults and providing complete transient electrical signature data for fault analysis. Fault signature fingerprint construction and template matching techniques can distinguish between different root causes of faults, such as contact erosion, coil aging, and connector corrosion, providing maintenance personnel with precise fault location guidance and avoiding blind repairs and repeated failures. Portable fault reproduction testing technology and environmental simulation devices can reproduce the P0233 fault phenomenon under controlled conditions, objectively verifying repair effectiveness and quantitatively confirming the fault elimination status, significantly improving the first-time repair success rate. The dynamic threshold adaptive adjustment mechanism and standardized testing process can automatically optimize detection parameters according to different vehicle characteristics and usage conditions, reduce the influence of human factors, and improve the consistency and reliability of diagnostic results.

[0046] See also Figure 3 , Figure 3 This is a schematic block diagram of the structure of an electronic device 300 provided in an embodiment of the present invention. The electronic device 300 includes a processor 301 and a memory 302. The processor 301 and the memory 302 are connected via a device bus 303, wherein the memory 302 may include a non-volatile storage medium and an internal memory.

[0047] The non-volatile storage medium may store a computer program including program instructions, which, when executed by the processor 301 , may cause the processor 301 to execute any of the above-mentioned engine fuel pump fault diagnosis methods.

[0048] The processor 301 is used to provide computing and control capabilities to support the operation of the entire electronic device 300 .

[0049] The internal memory provides an environment for the operation of the computer program in the non-volatile storage medium. When the computer program is executed by the processor 301, the processor 301 can execute any of the above-mentioned engine fuel pump fault diagnosis methods.

[0050] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the electronic device 300 involved in the solution of the present invention. The specific electronic device 300 may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0051] It should be understood that the processor 301 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0052] It should be noted that those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working process of the electronic device 300 described above can refer to the corresponding process of the aforementioned engine fuel pump fault diagnosis method, and will not be repeated here.

[0053] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0054] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for enabling an electronic device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0055] As described above, the above embodiments 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 above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these 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.

Claims

1. A method for diagnosing engine fuel pump faults, characterized in that: include: Collect the contact voltage, coil current, and ambient temperature and humidity parameters of the fuel pump relay to obtain P0233 fault circuit monitoring data; Analyzing the fluctuation of the relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal; Responding to the contact deterioration warning signal and monitoring the voltage drop and current fluctuation at the moment of P0233 fault occurrence in real time to obtain transient electrical characteristics of the fault; Based on the transient electrical characteristics of the fault, a fault feature fingerprint is constructed and matched with three root cause templates: contact ablation, coil aging, and connector corrosion, to obtain the root cause type of the P0233 fault; A maintenance test parameter combination required for fault reproduction is generated according to the P0233 fault root cause type, and the maintenance test parameter combination is executed to reproduce the P0233 fault phenomenon to obtain a fault repair verification result.

2. The engine fuel pump fault diagnosis method according to claim 1, characterized in that: The contact voltage, coil current and ambient temperature and humidity parameters of the fuel pump relay are collected to obtain P0233 fault circuit monitoring data, including: A fuel pump circuit test fixture is used to establish elastic contact connections with the relay contacts and coil terminals. An oscilloscope and multi-channel data recorder are used to perform impedance matching and noise filtering on the electrical signals to obtain the contact voltage and coil current. Monitor the temperature and relative humidity of the fuel pump working environment to obtain the ambient temperature and humidity parameters; The contact voltage, coil current and ambient temperature and humidity parameters are time stamp synchronized and data format standardized to obtain P0233 fault circuit monitoring data.

3. The engine fuel pump fault diagnosis method according to claim 1, characterized in that: The analyzing the fluctuation of the relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal includes: Performing Ohm's law calculation on the contact voltage and coil current in the P0233 fault circuit monitoring data to obtain a contact resistance value sequence; Performing sliding slice analysis on the contact resistance value sequence to obtain a contact resistance fluctuation characteristic data segment; Calculating the standard deviation and the coefficient of variation of the contact resistance fluctuation characteristic data segment, and extracting the frequency spectrum characteristic component of the resistance fluctuation by fast Fourier transform to obtain a contact degradation statistical parameter combination; The contact degradation statistical parameter combination is numerically compared with a standard deviation threshold and a coefficient of variation threshold to obtain a contact degradation early warning signal.

4. The engine fuel pump fault diagnosis method according to claim 1, characterized in that: The method of responding to the contact degradation warning signal and monitoring the voltage drop and current fluctuation at the moment of the P0233 fault in real time to obtain the transient electrical characteristics of the fault includes: Receiving the contact degradation warning signal triggers the oscilloscope to switch to high-frequency sampling mode, and at the same time, expands the buffer depth of the multi-channel data recorder to a 30-second time window before and after the fault, to obtain intermittent fault capture configuration parameters; A voltage drop detection threshold and a current fluctuation detection threshold are set based on the intermittent fault capture configuration parameters, and data recording is automatically triggered when the relay contact voltage or coil current exceeds the detection threshold range to obtain a fault capture trigger condition; The fuel pump relay circuit is electrically monitored according to the fault capture triggering conditions. When the P0233 fault occurs, the drop process of the contact voltage and the transient fluctuation of the coil current are synchronously recorded to obtain the transient electrical characteristics of the fault.

5. The engine fuel pump fault diagnosis method according to claim 1, characterized in that: The fault characteristic fingerprint is constructed based on the transient electrical characteristics of the fault and matched with the three root cause templates of contact ablation, coil aging, and connector corrosion to obtain the root cause type of the P0233 fault, including: Performing peak detection and reference voltage comparison on the voltage waveform in the transient electrical characteristics of the fault, calculating the percentage deviation of the voltage drop depth from the rated voltage and the waveform distortion, and obtaining the voltage distortion amplitude; Decomposing the coil current signal in the transient electrical characteristics of the fault in the frequency domain and extracting the current harmonic components; Analyzing the time difference between the relay receiving the control signal and the contact being fully closed based on the timing data of the transient electrical characteristics of the fault, and measuring the coil excitation establishment time and the contact action response time to obtain the relay action delay; The voltage distortion amplitude, the current harmonic components, and the relay operation delay are constructed into a fault feature fingerprint. The similarity matching between the fault feature fingerprint and three root cause templates (contact erosion, coil aging, and connector corrosion) is calculated to obtain the root cause type of the P0233 fault.

6. The engine fuel pump fault diagnosis method according to claim 5, characterized in that: The voltage distortion amplitude, the current harmonic components, and the relay operation delay are constructed into a fault feature fingerprint, and similarity matching between the fault feature fingerprint and three root cause templates of contact ablation, coil aging, and connector corrosion is calculated to obtain the root cause type of the P0233 fault, including: constructing the voltage distortion amplitude, the current harmonic component and the relay action delay into a fault feature fingerprint; Establish three root cause templates based on the preset fault root cause feature library: contact ablation, coil aging, and connector corrosion; The fault feature fingerprint is respectively calculated with the three root cause templates of contact ablation, coil aging, and connector corrosion to obtain three similarity distance values; The three similarity distance values are subjected to minimum value discrimination and threshold comparison, and the template with the minimum distance that is less than the preset matching threshold is selected as the root cause type of the P0233 fault.

7. The engine fuel pump fault diagnosis method according to claim 1, characterized in that: Generating a maintenance test parameter combination required for fault reproduction based on the P0233 fault root cause type, and executing the maintenance test parameter combination to reproduce the P0233 fault phenomenon to obtain a fault repair verification result includes: According to the root cause type of the P0233 fault, a preset root cause environment association database is queried to map the contact ablation type to the high temperature and high humidity environmental condition, the coil aging type to the temperature cycle change condition, and the connector corrosion type to the humidity shock condition to obtain the environmental trigger condition; Numerical calculations are performed on the temperature range, humidity range, vibration frequency, and voltage fluctuation amplitude based on the environmental trigger conditions and fault occurrence history data to determine the minimum trigger value and maximum safety value boundary of each environmental parameter and obtain the electrical parameter range; The environmental trigger conditions and electrical parameter ranges are matched and durations are allocated according to the timing requirements for fault reproduction, and the environmental warm-up time, fault induction time, and state stabilization time are set to obtain a maintenance test parameter combination including a temperature setting value, a humidity setting value, a load current value, a test duration, and an operation step description; The maintenance test parameter combination is executed to drive the environmental simulation device to reproduce the P0233 fault phenomenon, verify the maintenance effect and confirm the fault elimination status, and obtain the fault repair verification result.

8. The engine fuel pump fault diagnosis method according to claim 7, characterized in that: The execution of the maintenance test parameter combination drives the environmental simulation device to reproduce the P0233 fault phenomenon, verifies the maintenance effect and confirms the fault elimination status, and obtains the fault repair verification result, including: Inputting the maintenance test parameter combination into the temperature control module, humidity control module, and load simulation module in the environmental simulation device, automatically adjusting the ambient temperature, relative humidity, and fuel pump load current to the fault triggering condition according to a preset time sequence, and obtaining the fault reproduction environment state; Continuously electrically monitoring the fuel pump relay circuit based on the fault reproduction environment state to obtain an electrical characteristic record during the reproduction test process; Performing waveform similarity calculation and characteristic parameter comparison analysis on the electrical characteristic records during the re-test process and the transient electrical characteristics of the fault collected before the repair, to obtain fault characteristic difference data before and after the repair; The fault elimination judgment is performed based on the fault characteristic difference data before and after the repair. When the voltage distortion amplitude is reduced and the current harmonic distortion returns to the normal range, it is confirmed that the fault has been eliminated. Otherwise, it is determined that the repair is incomplete and needs to be reprocessed to obtain the fault repair verification result.

9. An engine fuel pump fault diagnosis device, characterized in that: Used to execute the engine fuel pump fault diagnosis method according to any one of claims 1 to 8, the engine fuel pump fault diagnosis device comprises: The acquisition module is used to collect the contact voltage, coil current and ambient temperature and humidity parameters of the fuel pump relay to obtain the P0233 fault circuit monitoring data; An analysis module, configured to analyze the fluctuation of the relay contact resistance in the P0233 fault circuit monitoring data to obtain a contact degradation warning signal; A response module, configured to respond to the contact degradation warning signal and monitor in real time the voltage drop and current fluctuation at the moment of P0233 fault occurrence to obtain transient electrical characteristics of the fault; A matching module is used to construct a fault feature fingerprint based on the transient electrical characteristics of the fault and match it with three root cause templates of contact ablation, coil aging, and connector corrosion to obtain the root cause type of the P0233 fault; The repair verification module is used to generate a repair test parameter combination required for fault reproduction according to the P0233 fault root cause type, and execute the repair test parameter combination to reproduce the P0233 fault phenomenon to obtain a fault repair verification result.

10. An electronic device, characterized in that: The electronic device comprises: a memory and at least one processor, wherein instructions are stored in the memory; The at least one processor calls the instructions in the memory to enable the electronic device to execute the engine fuel pump fault diagnosis method according to any one of claims 1 to 8.

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