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.

It's extremely difficult. Unauthorized modifications can lead to module current overload protection, resulting in a lock. In China, you need to use the factory online engineer account to reprogram it. It's basically impossible to perform online decoding overseas. We strongly warn against blindly modifying the electrical systems of modern integrated circuit vehicles.