Problem in transfering file via bluetooth
It all depends. When you want to connect a blue tooth to a phone, You will need to switch on the blue tooth device and the phones blue tooth you are pairing with.
When pairing both device, you will ask for pairing code, You four digit numbers(default code(0000). and pair.
After pairing both device, you detected paired, you can now use the blue tooth device with your phone.
there are no special code for pairing Blue tooth device.
Normal codes used are any four digit, four numbers you want to use.(0000, 1234).