Once the car system (especially in a closed ecosystem) undergoes a major version upgrade, its bootloader is usually locked, preventing downgrades. If this happens, there is basically no solution in an overseas environment. Therefore, we strongly warn: do not blindly insert a USB drive to upgrade while offline.

We can purchase the hardware (diagnostic device) on your behalf. However, the original online diagnostic accounts (especially those involving anti-theft programming and module matching) have strict domestic IP location and real-name authentication restrictions, making it very difficult to log in stably from overseas for a long time, and we cannot guarantee technical support for this.

We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).