What Are the Basic Procedures for Automotive Fault Diagnosis?
2 Answers
The basic procedures for automotive fault diagnosis include: 1. Understanding the initial condition; 2. Inquiry and test drive; 3. Verifying fault symptoms; 4. Analysis and research; 5. Reasoning and hypothesis; 6. Proposing diagnostic steps; 7. Testing and confirming the fault point; 8. Verification after fault elimination; 9. Identifying the fault. Automotive fault diagnosis refers to the detection, analysis, and judgment conducted under non-disassembly conditions to determine the technical status of a vehicle or to identify the location and cause of a fault when the vehicle has potential fault hazards, deteriorating technical conditions, or partial or complete loss of operational capability. The methods of automotive fault diagnosis are divided into: 1. Manual diagnostic method; 2. Instrument and equipment diagnostic method.
I've been working in car repairs for a long time, and diagnosing faults requires a systematic approach with several steps. First, gather detailed information from the car owner—such as the conditions when the issue occurs, its frequency, and symptoms, like engine shaking or stalling. Then, conduct a preliminary inspection: pop the hood to check for oil leaks, burnt smells, or loose components, and scan the dashboard for warning lights. Next, use diagnostic tools like an OBD scanner to read trouble codes, narrowing down the issue to specific systems like electrical circuits or the engine. After that, perform hands-on tests on key components, such as measuring battery voltage or using a multimeter to check circuit continuity. Don’t forget a simple test drive—drive a short distance to observe the car’s behavior. Avoid rushing through the process, as skipping steps often leads to misdiagnosis; many minor issues get exaggerated due to overlooking the owner’s description. Timely diagnosis saves major repair costs and prevents chain failures.
