[E46] Custom DIY OEM Bluetooth install, For thoses who don't want to donate a kidney

First, sorry about the length of the post.

I Thought I'd share this here and it seems to come up on other forums.

I've made my own BT loom as I didn't fancy paying a dealer £150 for the harness (update: NLA from dealers), I started looking on the internet about a DIY custom solution, an OEM ULF with a custom harness, after all the OEM ULF is just a BT module with an I-Bus interface, right.

Since my car has the 40 quadlock and SatNav, custom making the 54pin ULF harness was very straight forward, here is the 54pin pinouts.

Pinouts
=====================================
BM54 - Main, 16 Pin Quadlock Connector

X13646-10----------------------- MUTE -----------------------PIN 51 ULF
X13646-12----------------------- GND ------------------------PIN 36 ULF
X13646-15----------------------- +12 V Perm----------------PIN 17 ULF
X13646-16----------------------- +12 V Switched------------PIN 35 ULF

X13646-9------------------------ I-BUS -----------------------PIN 15 ULF
X13646-11----------------------- TEL ON ---------------------PIN 33 ULF

BM54 - Small, 12 pin connector (C Btm right)
X13649-6---------------------- Tel Audio Out + --------------PIN 37 ULF
X13649-12--------------------- Tel Audio Out - --------------PIN 38 ULF

Extras, MIC:

MIC + ----------------------------------------------------------PIN 1 ULF
MIC - ----------------------------------------------------------PIN 19 ULF
MIC Shield-----------------------------------------------------PIN 21 ULF

Eject box, 18 Pin elo connector
=====================================

GND-----------------------(Pairing switch)--/ ----------------PIN 32 ULF
Cradle_On--------------------------------------------------------PIN 11 ULF

Pin 1 = Green (PAIRING)
Pin 2 = Brown (GROUND)
Pin 5 = Red (ign or direct 12v +)
Pin 13 = White (Cradle_On) Pin 11 of ULF.

Or

Pin-7 Pairing Button------------PIN 32
Pin-8 Cradle_On
Pin-10 12v+
Pin-17 Ground.

I started by getting the 54pin plug from the dealer, as it was on back order, I looked around and came across the same plug used by Audi for there BT module, I ordered the plug and connectors, and they were here within 3 days.

54 Pin connector £1.97 ($4) Audi Dealer - Audi p/n 4e0-972-144.


Pins for connector £3.01 ea Audi Dealer - Audi p/n 000-979-010.


Several things of eBay:

Pair button ---------------£1.30 ($2.60), I didn't bother with the eject box as the phone is always charged and BT enabled, now changed to the OEM cradle (I got one cheap).


Leads (Mic & Switch)-----£4.49 ($10), used 2.5mm speaker lead. (as they don't have to carry any high voltages, I thought this would be OK, and it seems to work just fine).

Then I made up the 54pin plug.


I used 5m of lead for the Mic and 3m of lead for the Pair button, normal HQ speaker lead is fine for whats needed and exceeds the spec of the OEM wire thats used, and give very good results.

This is the finished result and work as OEM.



I had to get several bits from the dealer (its hard to believe but they were cheaper than eBay).

Antenna, antenna fakra lead, antenna bracket and mic.




The satnav detected the BT module straight away.


then select phone


Go through pair process and bobs you uncle.

Total outlay is approx £180 ($360), sound quality is much better than that of the nokia kit and I now have full integration with the MFSW/ SatNav display, as well as voice control, the phone book has transferred and you can use the buttons on the display to call and receive calls.

Well pleased with the results.

The beauty of the DIY option is that its bespoke, all the inputs/outputs are self contained in the retrofit loom, unlike the OEM BT loom which picks up inputs from all over the car (power/switched power/gnd/i-bus/tel on/mute etc).

HTH

P.S
I should have mentioned, mine was a lot easier to install than the OEM harness, I fitted mine without having to remove the passenger seat (as OEM), so I installed it in under 2 hours, not the 10 the the dealers say it takes.

Extra bits needed.
Bluetooth Antenna, BMW p/n 84-50-6-928-461,
Bluetooth Antenna bracket, BMW p/n 84-13-6-912-160,
FARKA ULF to Antenna, BMW p/n 61-12-6-912-541,

Microphone, BMW p/n 84-31-6 938-762, (saloon/coupe only)
Microphone Cover, BMW p/n 51-44-8 250-108,

Also, Since I would have been watching the tv anyway I don't count the time taken to make the loom up, but its roughly 4 - 5 Hours start to finish

 

I may have one at home (I had some spares left over so I made up a spare harness at the same time), I'll need to dig it out and test it.

It's for the BM54 radio module (40pin radio) not the 17 round pin type, let me have a look and get back to you, if that's OK.

You have a cab, so do you have the combo light/mic fitted in the roof of your cab or is it just a light module?

If it's just a light then you will require a different mic (I don't have the part number for that) and it makes the install a bit trickier, as it's mounted in the steering wheel cowl.

 

Will do

 

Real nice. I love how to's, specially those written by our own members. Stuck.

 

Hi Andy,

It depends on exactly which kit is installed, if you have the type with the 26DB rs232 phone module then you *may* be able to get the converter lead and the extra stuff, here is a pic of the upgrade kit, I think that navman in the USA do a kit/or the converter.

The problem with the 26pin rs232 plug is that it has more than 1 possible config so what works for one car may not work in another, it's a bit hit and miss, most people in your position, add the BT harness and dump the fixed kit.




If you have the 54pin (ulf type plug) then you can get a small converter plug from the dealers and it will allow you to swap the telephone module for the BT ulf, but you will still need the bits above (ulf, antenna, fakra lead and cradle) though, it just allows you to use your current lead.

HTH

 

Yes, it can, but the ULF would have to go behind the glovebox, (or you would need to run a fair amount of wire to the back), the radio module also has a different plug on the back and therefore needs the older style telemute lead.

I've never done one up front but It should be possible.

Here is the pin layout for the 17 round pin radio module.

 

Is that my ears burning...

Nice of you to say stu and tom, but I don't know everything, Just a few bits and bobs on the audio, nav and phone systems.

I might be making up a few BT harnesses in the next couple of weeks and I'm thinking of putting a complete BT retrofit kit together (harness, ULF, mic, antenna etc) and seeing how it does.

 

I've only just done one, but as yet I've not had time to make them up, and the price will depend on the ULF thats used, the newer the more expensive.

 

IPhone's only work well with a Gen13 ULF, which is loads of money, I think that you can get away with an earlier ULF but the Iphone needs to have the latest firmware on it.