Hello XXXXXX,
They are brand,vehicle, and model specific. Go to the phone's website. Download the application for YOUR car. Install to phone, then you should be able to follow the vehicles procedure to link to your phone !! Good Luck.
Press the ACCEPT button. Leave positive feedback if I have been helpful. Thank you. Dave
Sorry, but are you refering to the bluetooth pass codes?
If you are then these are specific to the TCU (telephone control unit) installed on your car not the model as the X3 and Z4 electronics are based on E46 3-series technology. Both of your cars should have come with a white peice of card with the passcodes printed on them in the service book wallet.
Or if they are not there then you have 2 options....
1.contact your dealer and have them read via thier diagnostic equipment (which they may charge you for)
2. gain access to the TCU as the code is printed on the side of it.
Rich.
ps if you need anymore info just ask.
BMW Technician
5 years main dealer experience.