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).

The technician will start the vehicle and turn on the air conditioning system, measuring the actual temperature at the vents at the lowest and highest settings with a thermometer; at the same time, they will connect a manifold pressure gauge to check if the refrigerant pressure in the high and low pressure lines is within the normal range, determining if there is a chronic refrigerant leak.

Basic perception functions (like Adaptive Cruise Control ACC, Lane Keeping Assist LKA, and Automatic Emergency Braking AEB) rely on the vehicle's local radar and cameras, and can operate normally overseas. However, advanced features that heavily depend on high-precision maps and cloud data (like Navigation on Autopilot NOA and Full Self-Driving FSD) cannot be activated overseas.