An OBD scan is one of the most cost-effective tools in a remote pre-purchase inspection, but you need to know what it can and cannot tell you. What it reveals well: current and stored fault codes across the engine, transmission, ABS, airbag, and body modules. A car with dozens of cleared codes in multiple modules may have electrical problems or a history of tampering. It also shows readiness monitors — if all monitors show 「not ready」 on a car that claims to be freshly serviced, the codes were probably cleared recently to hide something. What it reveals with the right software: live data. You can watch engine idle stability, coolant temperature under load, transmission shift behavior, and battery cell voltages on EVs. Abnormal fuel trims or misfire counters can flag worn injectors or coils before any warning light appears. What it cannot do: prove real mileage (odometers can be corrected digitally), detect physical accident repairs, or judge paint and rust. Practical advice: ask your inspector for a full-system scan report with screenshots, not just a 「no codes」 verbal summary. For Chinese brands, make sure the tool supports their protocols — mainstream scanners cover BYD, Geely, and Chery well, but some small brands need brand-specific software.

Interior assessment is divided into three core areas: the driver's high-frequency contact area (steering wheel, gear shift, edge of the driver's seat), central control button area, and rear seats and ceiling. The natural sheen of leather surfaces (patina) is normal; however, any physical damage (such as leather tearing, fabric burn holes, or plastic breakage) will be classified as "structural interior damage" and clearly marked.

A Chinese VIN is 17 characters, and decoding it takes minutes but reveals a lot. Positions 1-3 are the World Manufacturer Identifier. Cars sold domestically in China usually start with L (for example LFV for FAW-VW, LGB for Dongfeng Nissan), which tells you it was built in China rather than imported. Position 10 is the model year letter or number. Positions 4-8 describe the model, body type, and drivetrain, so you can verify the seller's description matches the actual car. Cross-check the VIN in three places: the plate at the base of the windshield, the sticker on the door jamb or B-pillar, and the registration certificate. Mismatched VINs or signs the plates were re-riveted are a serious red flag for a cloned or rebuilt vehicle. Use the VIN to pull a history report from a Chinese data provider and to verify recall status with the manufacturer. Any seller who hesitates to share the full VIN is telling you something important.