OK so you have a 2004 WDCT TCU. It has a 2.4GHz radio (cream FAKRA connector) that you can't connect your BT phone to. The TCU should work in Europe with 900/1880 SIM cards. The SIM inside the TCU is for BMW ASSIST. The sim in the cradle or in the TCU slot is for the WDCT handset. Here in England if you buy a THREE (3G provider) SIM, they share the 2G network with Orange/Tmobile for 900/1800 coverage.

Anyway, this is old technology.


Since you have the 54 pin connector you can swap your old TCU for a new TCU or ULF.


The TCU and ULF software and hardware got better as time went by. The last ULF was a GEN13. The last iBus TCU rolled out in the 2008/9 X3 facelift. Do not get confused when browsing eBay. After the E46/E39/E38/X5 Mk1/Z4 Mk1/X3 Mk1 the TCU went to optical fibre, and it gained a second connector next to the 54 pin one, and is not compatible with your car.

Pros and cons:

The ULF has voice control for the phone and Nav
The TCU has voice control for the Nav only

The TCU apparently has a better ring tone than the ULF.
The ULF needs a pairing button or eject box, the TCU does not.

The EU ULF appears to be quite tricky to pair in a retrofit.