What are the commonly used methods for automotive fault diagnosis?
3 Answers
Commonly used methods for automotive fault diagnosis include: 1. Empirical Method: This relies on the basic skills and extensive experience of drivers and maintenance personnel to quickly and accurately diagnose automotive faults; 2. Observation Method: Automotive mechanics carefully observe the fault phenomenon at the location indicated by the car user and then make a judgment on the fault; 3. Auditory Method: When the car is running, the engine operates under different conditions, and the car and engine as a whole emit a noisy but regular sound. When a fault occurs in a certain part, abnormal noises will appear. Experienced individuals can immediately diagnose the automotive fault based on the abnormal noises; 4. Test Method: This involves checking the functions of the car and engine without or with minimal disassembly to achieve the purpose of fault diagnosis.
I've been driving for thirty years, and fixing cars has become second nature to me. Diagnosing problems requires a step-by-step approach—first, listen to see if the engine sounds steady, check if any warning lights are on the dashboard, and sniff for any unusual odors in the car. Last time the coolant temperature warning light suddenly came on, I immediately pulled over, popped the hood to check the coolant, and found a cracked pipe leaking. If the car won't start, I always check if the battery terminals are loose first—it's much faster than calling a tow truck. Cars are like people; small issues left unattended can turn into big troubles. Don't wait until you're stranded on the road to panic. Keeping a multimeter handy to check voltage is practical, and you can even tell when the tires are low on air by the rolling sound. These experiences are the first line of defense for safe driving.
In the repair business, diagnosing faults has long been standardized. We most commonly use an OBD scanner—plug it into the port under the steering wheel, and it reads the fault codes in ten minutes. I remember a BMW once reported an oxygen sensor fault, but upon disassembly, we found mice had chewed through the wiring. Nowadays, the onboard computers in new models can detect 90% of issues, even analyzing motor current data streams for sticky power windows. Manual checks are still essential, though—like testing resistance section by section for wiring issues or removing wheels to inspect calipers for brake noise. Truth is, 4S shops have more advanced equipment. Our small shop’s survival trick? Swapping parts to test stubborn cases—soapy water from a spray bottle instantly reveals exhaust leaks.
