OBC Location

[jcp240z]

I am trying to determine where the OBC is actually located. The cluster and the MID/Nav are really just displays. What unit(s) actually does the trip functions, date/time, etc.
My 03 originally came with Nav & DSP. This was replaced with a Pioneer unit by the previous owner.
I would like to regain the OBC functionality but really don't want to obtain and refit the original hardware. If I could retrofit what is necessary fora high Display cluster, MID in the glove box I'd be happy.

[TerminatorX5]

when you use the button on the left stalk (BC button on turn signal lever), do you get any information on the cluster's alphanumeric display?

[jcp240z]

I get avg fuel, avg speed, but speed limit is blank, time/ date blank, trips etc. So the cluster works but I believe those functions managed some where else. I recall some where that they were in the MkV if you had Nav or in the radio module if not,but I can't find any info.

[TerminatorX5]

in the stock configuration, when you pressed and held the BC button for a few seconds, on the NAv screen you would get the screen that showed the checkboxes for the functions that you wanted to show up on the cluster. once the screen is replaced, you can't see them anymore...

[Qsilver7]

The OBC is in the IKE (instrument cluster electronics)...but it is controlled through the MID or Nav display in BMWs with the high instrument cluster...and the MID or Nav screen is also the OBC's primary display (not the instrument cluster's 20 digit alpha/numeric display).

That means (as you've experienced) once you remove the Nav display (or the MID)...you've removed the ability to set/start/reset/stop any of the OBC features. The 20 digit alpha/numeric display in the instrument cluster has first priority to the CHECK CONTROL system. The ability to display the OBC features there is a "fringe benefit". That is why the OBC must be "programmed" to appear in the cluster...and if any Priority 1 or 2 warning occurs...any OBC feature is immediately wiped from the cluster display. Also, if electrical power is disconnected...all OBC features programmed into the cluster will be wiped out and must be reprogrammed to appear there.

I'm not sure if the MID & Nav display connections are exactly the same...but if they are...you could find a used HIGH MID and reconnect it to the cluster and store the MID in the glove box or other location. This would allow you to reprogram the OBC features you wanted to appear in the cluster's display. Again, the only way to set/start/reset/stop any of the OBC features is thru the MID or Nav screen.

The turn indicator stalk only calls up the OBC features to appear in the HIGH CLUSTER...it has no way of setting/starting/stopping/resetting the OBC features.

Since you have the high cluster & DSP...you'd need to find a MID from an e39 or e53 that is configured correctly (has DSP & BC icons on the buttons along the right side):

_

Prior to 9/97 build date...the e38 & e39 high clusters had a separate IKE (which contains all the electronic data like OBC/VIN/Serv Interval/Mileage/etc) which makes it easy to swap clusters that had bad pixels etc...because you could just remove the original IKE and connect it to a replacement cluster...and VOILA!...no more problems. But after the 9/97 build date...the IKE was integrated into a one-piece cluster...thus making a "swap" more difficult due to the redundant data storage that is shared (and coded) with the LCM...which is specific to each BMW.

Hope this makes sense.

[Skyline]

The idea of using a MID located in the glove box can make sense, assuming you have somewhere to plug it in. Sometimes when an aftermarket radio is installed, they use an adapter harness and plug into the stock radio connector. Or worse, hack off the stock radio connectors, and just splice into to wires they need.

If you're lucky, the aftermarket stereo was installed using all new wiring, as would be done in a high end installation. (Running new RCA cables to amp(s) in the back, new speaker wire from amps to speakers, etc)

[Stanleyf233]

Did you sort this? I am exactly the same predicament although it will be of my own creating. my X5 4.4 sport has 16:9 satnav with DSP. I hate it, and will shortly be removing the multi changer, DSP amp, head unit, TV module, sat nav and radio unit (if i can). But as you say, we lose OBC functionality, over come by placing a MID unit in the Glove box. Mine is a single DIN flip out so will go above a correctly fitted MID unit.

Head unit removed, two plugs in the back. one blue, one white. White has now been adjusted (filed) to fit the black connector on my MID unit. I have two MID units, one is from a 5 series the other a 7 series (its smaller profile but exactly the same functions) both are refurbed units and neither shows any sign of life when plugged in.

This is now holding me up on my install! somebody must have done this before!!

Does my MID require coding to the car to work?

Anybody got any ideas??