What are the methods for automotive fault diagnosis?
2 Answers
Automotive fault diagnosis methods include: 1. Understanding initial conditions; 2. Inquiry and test drive; 3. Verifying fault symptoms; 4. Analysis and research; 5. Reasoning and hypothesis; 6. Proposing diagnostic steps; 7. Testing to confirm fault points; 8. Verification after fault elimination; 9. Fault detection. Automotive fault diagnosis refers to the detection, analysis, and judgment conducted to determine the technical condition of a vehicle or to identify the location and cause of a fault when the vehicle has potential faults, deteriorating technical conditions, or partial or complete loss of operational capability, without disassembly. Automotive fault diagnosis methods are divided into: 1. Manual diagnosis method; 2. Instrument and equipment diagnosis method.
When car owners come to me for help diagnosing vehicle faults, I follow a step-by-step approach. First, I gather information about the symptoms, such as engine shaking or warning lights on the dashboard. Then, I perform a physical inspection to check for leaks or loose wiring harnesses. Next, I use a multimeter to test voltage and resistance, identifying electrical issues like blown fuses or faulty spark plugs. For control system errors, I connect an OBD scanner to read trouble codes, which can precisely point to sensor or injector problems. Don't forget a test drive to listen for unusual noises and assess acceleration smoothness. For complex issues like transmission faults, I use a diagnostic computer for an in-depth scan, as modern vehicle ECU systems store extensive data. Avoid disassembling parts blindly—diagnose from simple to complex to save time and ensure accuracy.
