I-Bus install and ULF change on E86 BMW Z4 Coupe

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I-Bus install and ULF change on E86 BMW Z4 Coupe

Post by WayOfTheGinja » Sun Mar 14, 2021 4:15 pm

It's been about 6 months since I bought my E86 Coupe and I've been busy :driving: Kind of wish I'd bothered with a full build thread but so far I have; changed the front badge, successfully stopped the driver's seat rattling by spraying teflon lube into the sides, replace the brushed aluminium trim with some in much better shape from eBay, cleaned the gunk out of the lighter socket and got it working, replaced the ash tray, replaced my wingmirror glass and got the heating working on them again, tightened the struts under the bonnet and fixed that rattle, cleaned my VANOS solenoids, added door speakers and sound deadening, added an aux socket (https://fruitycarcables.co.uk/), attached bluetooth media streaming to the CD changer wiring, changed the gear knob, changed the gear change surround, upgraded the windscreen wipers, (paid someone else to) change the windscreen, replaced the cheapo stubby with the official BMW one (so worth it - FM reception infinitely better!!!), sound generator mod and collated the previous service history into something more respectable looking (phew) but... that damned factory bluetooth (ULF) still didn't work.

I could occasionally get it into pairing mode but it showed up as "BMW ULF" (not BMW then the last 5 digits of the VIN as expected) and the PIN was 1234 (not the one written on the ULF). If it ever paired it would instantly disconnect.

So... bought myself an I-Bus interface from https://modbmw.com/shop/ibus-interface/ and decided to plumb it in behind the head unit (as the CD changer wiring where it can also be fitted is a b*tch to get to in an E86). Used some Scotch lock style wire-taps (pin-out - viewtopic.php?t=42371) and plugged it into my better half's laptop - after manually installing the com-port driver (just Googled the misbehaving entry in device manager) it connected to Navcoder.

Playing with Navcoder for an hour or so confirmed my suspicions - the original ULF did not behave how it should so I pulled it out and installed one from ebay (older model number, pulled from an X5, £20 off eBay) - reconnected the battery, plugged in Navcoder again and bingo - no fault codes. (Accessing the ULF or CD changer wiring in an E86- https://www.bimmerfest.com/threads/07-z ... se.507452/) Still wouldn't stay paired though... :headbang: Got fed up and decided that I was never going to have my factory phone prep working, disconnected the battery, bolted everything back together with the X5's ULF in place just in case. Re-connected the battery and there it was, connected to my iPhone 11, not dropping the connection! It all works perfectly, phone book comes up on the Business head unit, successfully made a couple of calls! Ultimately I'm not sure what changed between my first and second test, I'm never going to unpair it as I fear this was a one off!

So this whole endeavour cost me maybe £70 (I-Bus, cable clips, new ULF and Navcoder licence). I was worried that, despite a LOT of forum reading it wasn't going to work but several of my leaps of faith paid off:

- You can easily install an I-Bus interface behind the head unit
- "K-Bus" is interchangeable with "I-Bus" in this context - not sure what the actual difference is but documentation varies
- A different model ULF can be swapped in without coding it (although I used Navcoder to check for fault codes, easily activate BT pairing and to adjust the bluetooth device name to match my car's VIN)
- An iPhone from 2021 can connect with a ULF from 2004, even if it requires a few goes

Next thing I want to find out is if you can connect a USB-OBD cable and use Navcoder as I was going to try this but nowhere could I find explicit confirmation. Now that I've got everything else this is only a £15 outlay... watch this space!

Photos in approximate build order plus a sweet shot of the car (just because...) outside my folks' garage during one of our brief intermissions between lockdowns last year.

Anyone want any advice or help on this, or any of the mods detailed in the first paragraph then get in touch.

Now to save up for some Eagle asymmetric F1s to replace these cheapo "Rapid P609s" that someone cruelly put on this lovely car...
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E86 Z4 Coupe - Montego Blue

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I-Bus install and ULF change on E86 BMW Z4 Coupe

Post by dj_jormi » Sun May 02, 2021 6:54 pm


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