Vehicle Current Sensor Diagnosis Ignition Off On States
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for diagnosing abnormalities in current sensors in vehicles are prone to errors due to temporary conditions such as condensation, which can lead to false diagnoses of permanent abnormalities, resulting in unnecessary inspections or repairs.
Innovation Solution
The system acquires two current values, one during an ignition-off operation and another after ignition-on before the current path becomes conductive, allowing for a more accurate diagnosis by comparing these values within specified reference ranges, and notifies the user only when a true abnormality is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If abnormality diagnosis is performed based on current sensor detection value in ignition-off state, then diagnosis can be made when current does not flow, but temporary abnormalities such as condensation cause false positive diagnoses
Solution Approach 1:
The system performs preliminary abnormality diagnosis in the ignition-off state to detect potential abnormalities, then performs a second diagnosis in the ignition-on state to confirm whether the abnormality is temporary or permanent. This preliminary action followed by confirmation resolves the contradiction by reducing false positives while maintaining diagnostic capability.
Solution Approach 2:
The system uses feedback from the first diagnosis result to determine whether to perform the second diagnosis. When the first diagnosis indicates an abnormality, the system feeds back this information and performs additional diagnosis in the ignition-on state to confirm the abnormality type, thereby improving diagnosis reliability without sacrificing accuracy.
2Loss of time
If diagnosis is performed immediately in ignition-off state, then diagnosis can be made quickly, but condensation may still be present causing erroneous abnormality detection
Solution Approach 1:
The system performs a quick preliminary diagnosis in the ignition-off state to identify potential abnormalities, then conditionally performs a second diagnosis in the ignition-on state. This approach minimizes time loss by only performing the second diagnosis when the first diagnosis indicates an abnormality, while still ensuring accurate detection by confirming results when needed.
Solution Approach 2:
The system performs partial diagnosis (first diagnosis) in the ignition-off state as a screening step, and performs complete confirmation (second diagnosis) only when necessary. This partial action approach reduces overall diagnosis time while maintaining accuracy by applying the full diagnostic process only when required.
3Device complexity
If only single current value measurement is performed, then measurement process is simple, but cannot distinguish between temporary and permanent abnormalities
Solution Approach 1:
The measurement process is segmented into two distinct phases: first measurement in ignition-off state and second measurement in ignition-on state. Each phase serves a specific purpose - the first detects potential abnormalities and the second confirms the type. This segmentation allows simple individual measurements while achieving complex diagnostic capability through their combination.
Solution Approach 2:
The system performs periodic measurements at different operational states (ignition-off and ignition-on) to detect abnormalities. By measuring at multiple periodic intervals corresponding to different vehicle states, the system can distinguish between temporary condensation-related abnormalities and permanent sensor failures without excessive complexity.
Data Source
AI summary
A vehicle includes an electronic control unit. The electronic control unit is configured to detect a first current value in a period in which a current path is switched to a non-conductive state by an ignition-off operation. The electronic control unit is configured to detect a second current value in a period that is after an ignition-on operation is performed and before the current path is switched from the non-conductive state to a conductive state in the case where the first current value falls out of a specified reference range. The electronic control unit is configured to diagnose that there is an abnormality of the current sensor when the second current value falls out of the reference range and to diagnose that there is no abnormality of the current sensor when the second current value falls within the reference range.