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.

Most new car manufacturers' e-SIMs are directly soldered onto the T-Box motherboard (surface-mounted) and cannot be removed and replaced like a phone. Unauthorized desoldering of the motherboard may cause complete communication failure in the vehicle, and we strictly prohibit this operation.

The technician will put the vehicle in neutral on the lift, rotate the wheels, and listen for any abnormal metal gear whine from inside the motor reducer, and check for gear oil leaks at the joints of the reducer housing.