Being out in LA, I recently bought a car – I ended up with a used BMW. It’s pretty sweet, but I’m me so obviously I’ve moded just about everything I can without actually buying parts. Mostly that means software mods – windows up on key fob lock press, that sort of thing. But I’ve also been trying to mod bluetooth into it, and only recently had success. Tonight I got curious and took the module which controls bluetooth and USB aux-in apart (referred to as a MULF2 High Basis, it lives in the trunk and connects to a USB plug in the center console). Here’s what I found.
TOP SIDE: Not much interesting, mostly glue logic.
OASIS OS81050
MOST bus interface controller
http://www.smsc-ais.com/AIS/content/view/172/216/
MAX1793
LDO Regulator
LVC14A
Hex Schmidt Trigger (glue logic)
NXP LVT244A
Octal buffer (glue logic)
BOTTOM SIDE:
NXP SAF1562
PCI USB 2.0 Host Controller
http://www.nxp.com/documents/data_sheet/SAF1562.pdf
This one’s interesting in that it’s a full-fledged host controller like you’d find in your PC – it advertises compatibility with built-in OS drivers in Linux and Windows. It suggests that the board is probably running some kind of embedded Linux, which makes lots of sense. Interestingly, it looks like the chip has both 2x USB1.0/1.1 controllers and a separate USB2.0 controller, with two transceivers (physical ports on the chip) for them to connect to. So you can be running 2x 1.1 ports or 1x 1.1 and 1×2.0, for example. If I had to guess, the controller is running 1 and 1, with the USB2.0 dedicated to the center console port, and the USB 1.1 going to the on-board bluetooth controller (see below).
Spartan XA3S500E
500k Gate Spartan 3E automotive FPGA
http://www.xilinx.com/support/documentation/data_sheets/ds635.pdf
Not especially surprising – if I had to guess, they’re using it to implement a MOST PCI controller or something like that. Really, it could be anything or a bunch of things, though.
Renesas SH7780 (R8A7780)
400MHz 32-bit CPU with 32-bit PCI bus
http://www.renesas.com/products/mpumcu/superh/sh7780/sh7780/index.jsp
This isn’t especially interesting. Just some generic RISC CPU. But it probably has the horsepower to run a stripped-down embedded linux. More likely, it’s actually not, though, it’s probably running a lighter-weight RTOS.
9DF42
Definitely DRAM or SRAM of some kind (running memory for the CPU)
Unfortunately, I can’t find any info on size or anything. If it’s big DRAM, that probably means the board runs embedded linux. If it’s smaller, probably a more compact RTOS. Tough to say – the 512mbit flash is definitely program memory (the SH7780 has none), and 512Mbit (64MB) is big enough for a compact embedded linux.
It’s interesting, I’m not really sure what the unpopulated BGA (ball-grid array) below the flash would have been. It doesn’t look like a spot for another RAM or flash chip, which would have been pretty expected (use free space on your PCB to add more ram, then if the programmers can optomize the software enough, just stop populating one chip to save a couple bucks a unit).
BlueCore BC41B143A
Bluetooth 2.0+EDR USB 1.1 Slave
http://pdf1.alldatasheet.net/datasheet-pdf/view/114800/ETC1/BC41B143AXX-IXB-E4.html
This chip runs the Bluetooth show. Basically, it’s a USB1.1 Bluetooth dongle plugged into the computer that runs on the rest of the board. Via software in the chip, you can choose to implement whatever profiles you want supported by the Bluetooth 2.0+EDR spec, including Handsfree (as they’ve done) and probably A2DP too (wonder why they haven’t?). It could be that the rest of the computer is too slow to handle A2DP, or that streaming the audio data from the chip requires a USB2.0 port (the only one of which I can only presume is occupied by the center console port). Curious either way why the hardware should theoretically support bluetooth streaming, but they’ve seemingly omitted the capability.
BONUS: I forgot to write the number of the chip on the top right. Initially I thought it might be an audio DAC, but maybe or maybe not. After USB and MOST, there are 6 wires going into the MULF – the big ones are pretty clearly +12V and electrical ground. That leaves 4. They could be l/r/ground/something, but I think not. I think they’re CAN-HI, CAN-LOW, CAN-V+ and CAN-GND for diagnostic/vehicle bus communication. Most people tend to think diagnostics for the MULF are over the MOST port, and there’s a MOST-CAN bridge somewhere in the dash, but I’d still bet anything those 4 are CAN for basic control (the vehicle is on, do your thing, etc).
If that’s true and no analog audio out happens in the MULF, I’m not sure why they didn’t simply implement A2DP. It’d have been easy enough. And now that I think of it, the chip is probably an audio ADC for microphone input, since that IS wired into the MULF. Maybe I’ll go pull mine apart again and probe it, now I’m curious.
@manuel I don’t know what you’re asking about plugged or welded. The chip is soldered, and yes, you could replace it with a sufficient hot air station (a temperature-controlled rework station, I mean). It’s a tricky process and only relevant if you can be reasonably sure that chip itself is fried.
Buenas tardes Alex¡
Tengo un e91 Lci 2009. Me ha dejado de funcionar el bluetooth y marcación por voz. He leído que el modulo electronico Mulf2 que tengo se ha roto. Que componentes del interior de este son los que tengo que reemplazar por experiencia y casos de otras personas?
Un saludo y muchas gracias.
Hi have replaced my MUlF2 with one from eBay. I have BMW, but fitted a replacement from a mini it seem when I pair. Not able to sync phone book from iPhone etc. how do I do this ? Didn’t understand the comment above about “empty man file “ also noticed that I don’t have as many voice control options. Can you provide the simple way to get these working.
Hello Alex.
Sorry for disturbing you on such an old topic but I could really, really use some help.
I have an E61 2009 model with no BT connectivity whatsoever. Do you possibly have some kind of schematics of what I need to add to retrofit the MULF 2 to my car?
Thank you for your time and reply in advance!
Hi Alex, I hope you’re still responding!! My 2010 bmw 128i convertible is having radio issues. The mechnaic replaced the fuze box in the car but now there is a new issue ever since pickup. The radio has a faint clicking noise, the radio will randomly shut off and power on when listening to the radio, the aux, and USB don’t work (it came from the factory with that), the sos is disabled, and the phone is disabled. That’s my first issue my next one I don’t think it is related but it also might be because both issues started happening after the mechanic; the passenger seat occupancy sensor warning light (the mechanic said) on the dash, it’s just the airbag light. is there any workaround for that, or is it just that sensor, or could the connection be loose? Nothing was wrong with the car before the mechanic. when for a new starter cause it didn’t start, and they said it was because the fuze box replaced that. It turned out that the starter also didn’t work, so they also replaced that. If you have any answers, thank you a lot Alex. I do not want to go back to the mechanic. It was a bad experience, and’d rather do it myself if possible.
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It sounds a lot like when the mechanic replaced your fuse box, they finished the job with the wrong configuration of fuses for your car. I’m suspicious of why they replaced the fuse box at all if the starter was actually dead – that should have been a highly avoidable mistake.
Anyway it sounds like your telematics unit is simply unplugged, so I’d bet if you find the fuse for it, there simply isn’t one there. I’d start there. The radio randomly restarting and the air bag light are suspicious, but if the wrong fuses are installed right now as I suspect, I suppose those could be the result of other missing fuses too.
I’d find the fuse diagram for your year, go fuse by fuse and decide which are things your car definitely has, and make sure all of those circuits have the correct size fuse in the correct position.
Just for anyone that might be interested the 9DF42 memory is actually D9FQV which is a Micron part – MT46V16M16BG-6:F-ND. The datasheet is currently available from DigiKey.
On your “MULF2 Top” image, would you have any idea what the vertical components / values (would likely be) on the bottom right next to the blue plug (approx 3 pins up from the bottom)? I see a feed through capacitor and a regular cap under it, but the components directly to the right of it on my board have fried. No idea what they are.
Thanks
@Tim Values, no clue at all. The one on the far right is a cap too, but no idea about value. My best guess, and it’s not a great one, is that the other is either a high voltage cap, or maybe a high voltage resistor, based on its length. I don’t like that logic since the copper its attached to isn’t separated by much from the other polygons that are not obviously high voltage.
Hi, is it possible to change bluetooth 2.0 to 5.0 in mulf2 module?
I’m going to start with “definitely not,” but for what purpose? Why do you ask? What do you want out of such an upgrade?