Originally Posted by Brian-bmw

The ULF and TCU modules are two different components that can provide Bluetooth capabilities. The ULF is solely dedicated to Bluetooth. The TCU does a lot more, but only the newer modules have Bluetooth and Voice Recognition. Ironically, the TCU is about ½ the cost of a ULF.

Here is a high-level summary of the two. There may be more differences, because this is largely based on observation from the BMW community.

* All ULF modules provide Bluetooth
* Only the newer TCU modules have the Bluetooth feature

* Most ULF modules have built-in voice recognition
* ULF has voice recognition enabled in the factory default coding
* Only the newest TCU modules have the voice recognition feature.
* TCU has voice recognition disabled in the factory default coding
* NavCoder can enable and disable voice recognition in both TCU and ULF modules

* ULF has the complete VR instruction set that includes navigation commands
* TCU only has the telephone-related VR instruction set

* ULF requires a pairing button (typically with an eject box and and adapter wiring)
* TCU does not require a pairing button

* ULF 13th generation discounted "official" retail price is $455 (Tischer BMW as of June 2009), but unavailable through US dealers
* ULF 13th gen typically costs >$600 from eBay and other non-BMW sellers
* TCU costs $328 + $50 core (Tischer as of June 2009), and is easily available through all US dealers

* ULF 13th prices used on eBay are typically around $500
* TCU used prices on ebay are typically arond $250 for the newest version

* TCU seems to have better in-car volume than the ULF (my own personal experience comparing my ULF to two other TCU installations).

* TCU shows signal strength on the navigation screen telephone menu.