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.

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.

The technician will check the production date codes and brand logos in the lower left corner of all the car's glass (including the windshield, four doors, and rear window) to see if they match the vehicle's factory date on the nameplate. If any glass is found to have a date later than the vehicle's production date, it will be recorded as evidence of a "previous damage replacement."