BlueBus: A fully integrated A2DP Bluetooth solution

[nextlvel]

I tried searching through the thread, but the search isn't the best, or maybe it's my skills. Has anyone had the issue of, after turning off the car, then getting back in, say 5 mins later (fueling up at a gas station) my iPhone 14 Pro will connect to the bluebus and show the audio metadata but not produce any sound? Thanks in advance! t3ddftw

[Der_Spanier]

What PSUEng said is correct -- IHKAs made after 09/2003 do not have this bug. The problem is that the LSZ I/O status response message, to make the comfort blinkers work, is longer than they programmed the IHKA to accept which results in undefined behavior.

Thanks Ted!

Sounds like there’s no other way to fix this other than to replace the IHKA. Edit: ordered a new module with the latest part number (64116956319, SW version 19.0, build date 02/2005). That should fix the problem. The middle part of the dash will get quite the upgrade thanks to the Bluebus... first a 2007-built CD53, now a 2005 IHKA.

Today I changed the VO to reflect all the spec changes. It has fixed an issue I was having with the CD53 I got, so it wasn’t a complete waste of time, but the climate control issue is still very much present.

[fuddy]

The comfort blinkers are up there as one of my favorite features.

It saved me the trouble of sourcing another LCM

[fuddy]

What PSUEng said is correct -- IHKAs made after 09/2003 do not have this bug. The problem is that the LSZ I/O status response message, to make the comfort blinkers work, is longer than they programmed the IHKA to accept which results in undefined behavior.



Does it have the oval mirror or the mirror with the SOS button? If it has the SOS button, then the connector is probably already connected to the BMW Assist Module (TCU):




Thanks!
-Ted

Ah, yeah I have the SOS mirror. I see I can remove the TCU completely and connect the cables to the bluebus.

[///Marecki]

The comfort blinkers are up there as one of my favorite features.

[PSUEng]

If it helps anyone out since it may be that the earlier versions of the updated IHKA may not work (if I read Ted's comment correctly), here is a photo of my original unit from my 12/2002 built coupe (background) and the replacement IHKA (foreground). Note the date stamp info on the updated unit. Zero issues since upgrading. I pulled this one apart and cleaned the temp sensor and I think it actually functions better than my original unit.

[t3ddftw]

I need to do this as mine has this issue. Do you happen to know if M3's have a specific control unit compared to non-M's?

Nope; they are also fully plug and play across all MYs. Grab one from a facelift car at the junkyard and send it

-Ted

[ejendow]

Correct. Most, but not the very early, facelift IHKAs (with the buttons beside the LCD) do not have this issue..

-Ted

I need to do this as mine has this issue. Do you happen to know if M3's have a specific control unit compared to non-M's?

[t3ddftw]

Similarly, it would fix the error if I install an IHKA from 09/2003 in my 2002

Correct. Most, but not the very early, facelift IHKAs (with the buttons beside the LCD) do not have this issue..

-Ted

[Andy2424]

The I/K-Bus spec says that the maximum frame size is 32 bytes, but being that so many different OEMs were part of making modules for these cars, they didn't all understand or care about that "limitation". Of course, the guy who sat down and wrote the code for the IHKA DID read that and probably just `memcpy(frame, buffer, sizeof(buffer));`

Similarly, it would fix the error if I install an IHKA from 09/2003 in my 2002

[t3ddftw]

I didn't know what the root cause for this bug was until now. Amusing!

The I/K-Bus spec says that the maximum frame size is 32 bytes, but being that so many different OEMs were part of making modules for these cars, they didn't all understand or care about that "limitation". Of course, the guy who sat down and wrote the code for the IHKA DID read that and probably just `memcpy(frame, buffer, sizeof(buffer));`

[heinzboehmer]

What PSUEng said is correct -- IHKAs made after 09/2003 do not have this bug. The problem is that the LSZ I/O status response message, to make the comfort blinkers work, is longer than they programmed the IHKA to accept which results in undefined behavior.

I didn't know what the root cause for this bug was until now. Amusing!

[t3ddftw]

Thanks for your feedback!

I’ll get my car’s VO to match its actual equipment and if the issue persists, get in touch with Ted for proper support. I’ll keep you all posted in case someone else has the same problem.

What PSUEng said is correct -- IHKAs made after 09/2003 do not have this bug. The problem is that the LSZ I/O status response message, to make the comfort blinkers work, is longer than they programmed the IHKA to accept which results in undefined behavior.

So just got mine, installed it on my 04 M3 Cabrio, bluetooth works great. I can't find the harness for the phone connector though. Anyone have tips for cabrio owners? Car is pre wired for phone.

Does it have the oval mirror or the mirror with the SOS button? If it has the SOS button, then the connector is probably already connected to the BMW Assist Module (TCU):




Thanks!
-Ted

[fuddy]

So just got mine, installed it on my 04 M3 Cabrio, bluetooth works great. I can't find the harness for the phone connector though. Anyone have tips for cabrio owners? Car is pre wired for phone.

[Der_Spanier]

I had the same issue in my 2003 M3 and if I recall, Ted advised me to either 1] turn off triple blink or 2] upgrade to the later model HVAC control module. I upgraded the module and no problem since. Contact Ted and he'll give you proper direction; great person to work with.

Thanks for your feedback!

I’ll get my car’s VO to match its actual equipment and if the issue persists, get in touch with Ted for proper support. I’ll keep you all posted in case someone else has the same problem.