Universal charger and hands-free kit (ULF) control unit: Construction

The ULF control unit comprises the components illustrated in the block diagram below, which includes signal inputs and outputs and power supply:

Fig 1: Identifying ULF Control Unit Components

Courtesy of BMW OF NORTH AMERICA, INC.

LEGEND FOR ULF CONTROL MODULE COMPONENTS

Index	Abbreviation	Description	Explanation
- - -	BT.ANT	Bluetooth antenna	Bluetooth antenna
1	PM	Power management	Voltage monitoring
2	MPC	Microprocessor	Microprocessor
3	EEPROM	Electronically Erasable Programmable Read-Only Memory	Fault memory
4	SDRAM	Synchronous Dynamic Random Access Memory	Working memory
5	FLASH		Data memory
6	BTM	Bluetooth module	Bluetooth interface
7	BTM	Bluetooth module	Bluetooth interface
8	NF_OUT	Loudspeaker	Voice output
9	MICRO	Hands-free microphone	Voice input
10	S/E-button	Transmit/receive button	Button to accept and end a phone call
11	K bus	K bus connection	Connection to other K bus components
12	RAD_MUTE	Radio mute	Signal to mute the audio system during a phone call
13	Kl.30	Terminal 30	On-board supply voltage
14	Kl. R	Terminal R	Ignition lock position 1 (terminal R)
15	Kl.31	Terminal 31	Earth
16	PSU	Power supply unit	Power supply
17	MUTE	Interface for radio mute	Interface for output of signal for radio mute
18	K bus	K bus interface	Interface for K bus communication

The connection of the ULF control unit to the vehicle electrical system is made via a 54-pin connector. Refer to PIN ASSIGNMENT, 54-PIN MULTI-PIN CONNECTOR .