Obd doesn't link
 

Hello, first I want to thank everyone for this magnificent forum. After this, I explain my case. I owner a mini cooper s r53. The airbag light was on several months ago and the car is running well but two weeks ago i traid to connect the computer and solve the airbag problem but the obd doesn't link and appear ' is not possible to link with the ecu". So i can't check it.
i test fuses, relays, connetions wiring from fuses box and everything is okay.
please, i need help.