Interface box High

The interface box High (ULF-SBX-H) is used to connect Bluetooth-capable mobile phones to the vehicle electrical system. The other functions depend on the vehicle equipment (e.g. M-ASK language processing system, AUX-IN connection with USB connection).

The interface box High contains no transmitter and receiver module for GSM mobile communication. This function is contained purely within the customer's mobile phone.

The Bluetooth connection between the mobile phone and the interface box High is established automatically. A precondition for this is that the mobile phone has logged on once to the interface box High.

Depending on the vehicle equipment the interface box High can be installed along with the Telematic Control Unit (TCU). In this case the Telematic Control Unit always assumes control of the telephone.

Functional description

The function for making a phone call with a mobile phone and the interface box High (ULF-SBX-H) is based on wireless data transmission using the Bluetooth radio standard.

Functions inside the vehicle:

  • Automatic prioritisation for establishing connection according to the list of mobile phones signed on
  • Hands-free mode with full-duplex transmission, echo compensation and display of the current operating mode
  • Language processing system
  • Transfer of audio data, telephone call information (e.g. GSM signal strength), telephone book and status of the mobile phone
  • Communication via a USB audio interface with connected external audio source

    The USB audio interface consists of a USB connection and an AUX-IN connection. The USB connection is used for data transfer and electrical connection of connected audio sources with USB connections.

  • Automatic charging of the mobile phone rechargeable battery if the corresponding snap-in adapter has been installed.

4 Bluetooth mobile phones may be logged on to the interface box High at the same time.However, the logged on mobile phones can be only be used one at a time. The automatic connection of already logged on mobile phones takes place on the basis of the pairing list.Mobile phones that are further up in this pairing list are logged in first and thus connected more quickly than mobile phones that are further down. If a fifth mobile phone is logged on, one of the first four logged on mobile phones is deleted from the pairing list.

In order for the interface box High to be functional, every mobile phone to be used must be logged on at least once. To do this, the interface box High needs to be in pairing mode. The linking is supported by the pairing assistant.

The pairing consists of 4 steps:

  1. Activating Bluetooth on the mobile phone and in the vehicle
  2. Pairing using the settings menu in the vehicle
  3. Entering the Bluetooth passkey on the mobile phone and in the vehicle
  4. End pairing

The Bluetooth connection is established once the pairing menu is exited.

After replacing the interface box High, log the Bluetooth mobile phone in again.

After replacing the interface box High (ULF-SBX-H) the Bluetooth mobile phones need to be logged in again. The Bluetooth passkey can be selected at random.

The interface box High (ULF-SBX-H) needs to be re-encoded in the following instances:

  • after replacing the interface box High
  • after replacing the head unit

When taking a call using the buttons on the multifunction steering wheel the interface box High switches to hands-free mode.

Connecting MP3-Audio sources to the USB or AUX-IN connections

The interface box High is always installed into the vehicle in combination with the 6FL USB audio interface option. In the interface box High the digital audio signals sent by the USB interface are decoded and sent to the Media Oriented System Transport (MOST). In addition the analogue audio frequency signals from the audio socket or AUX-IN connection are prepared for the MOST

Data import via the USB audio interface (optional extra 6FL) in the centre console is not possible. This interface is also used for connecting external audio sources (e.g. Apple iPod or MP3 player with USB connection, USB sticks or mobile phones with MP3 players). Hard disks however cannot be connected.

The external audio sources are played via the vehicle's audio system.

When connecting an external audio source via USB the contents of the source will be read by the interface box high. The directory structure will be prepared for display in the central information display (CID) and stored. Only the track information is stored in the interface box High, not the actual MP3 files. IN addition a plausibility check is run to see if the track can be played in the vehicle. Only tracks that can be played will be displayed.

It can take some time to prepare the files. While the database in the interface box High is being populated with track information it is only possible to select music files by directory navigation. Once the database is complete the tracks can be selected by genre, artist and album.

Approx. 20,000 titles can be stored in the interface box High. Once the storage capacity is reached the tracks of the audio source plugged in first will be overwritten. If this source is then re-plugged in the track information must be read off it again. Depending on the memory capacity of the external audio source, this scanning can once again take a while.

The external audio source can be controlled via the central information display (CID) and the controller (CON).

Item Description Item Description
1 Interface box High (ULF-SBX-H) 2 USB port
3 Connection for Bluetooth aerial 4 MOST interface
5 54‐pin plug connection

Structure and inner circuit

The interface box High (ULF-SBX-H) is connected to the vehicle electrical system by means of a 54-pin plug connection.

The interface box High has a MOST interface, a USB connection and a connection for a Bluetooth aerial.

The rear current distributor supplies the interface box High with terminal 30B.

Item Description Item Description
1 Interface box High (ULF-SBX-H)

Pin assignments

The graphic above shows only the supply and bus connection. The current pin assignment can be found on the BMW ISTA (Integrated Service Technical Application) diagnosis system among the wiring diagrams. Click on the component code in the wiring diagram to activate the "Installation location" and "Pin assignment" tabs.

Nominal values

Observe the following nominal values for the interface box High:
Variable Value
Supply voltage 9 to 16 V
Supply voltage at USB connection 5 V
Nominal current at USB connection 500 mA
Temperature range -40 to 85 °C

Diagnosis instructions

Failure of the component

If communication to the interface box High fails, perform the standard checks (global testing procedure). If there is an internal control unit fault, the following behaviour is to be expected:

  • Fault entry in the interface box High (ULF-SBX-H)

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