The Guys are correct, the OBD socket under the steering wheel will only read the engine module, to read the airbag module this has to be done using a 20pin to 16pin obd2 cable changer plugged into the engine bay diagnostic socket.
Year 2000 car should connect ok to OBD2 scanners, I use a Creator 310+ scanner which connects ok to my 1999 Z3 and my 2003 Z4.