Dead iDrive Controller debugging

[Cyberdemon]

So a few days ago I took my iDrive screen out to polish some scratches on it. While I was working on the car out in the cold, I had the battery connected and because my battery was 11 years old and I kept jumping in and out of the car, eventually the voltage dropped, the car woke up with a million errors and I knew it was time to change the battery.

Fast forward, I changed the battery with the same type (Duralast H8-AGM, 900CCA, 94AH vs the 90AH oem battery), connected everything back and everything seems fine except my iDrive controller is dead. The iDrive display is working, car drives fine, sound is working and I can still change between presets using the hard keys.

I registered the battery and hooked up to ISTA+ and was getting a few different codes.


I don't remember exactly, but I'm almost positive the iDrive controller worked after I reinstalled the screen (theory #1 was I borked or tugged something the wrong way when removing the screen). I remember when I turned the car on using the iDrive to scroll to the vehicle status to see the litanny of low voltage and other errors - so I'm almost positive it worked pre-battery change.

I had cleared the codes once with ISTA, it was also giving me a MOST bus error that cleared itself.

Are there any connections for the MOST bus inside the battery well area that I could have screwed up by installing the battery?

Update 1:
-Removed the display and CIC unit to check the connections and make sure nothing got squished when installing/reinstalling the carplay box. I can try disconnecting the Carplay box if it comes down to it though it had been working fine and is still working fine (can confirm it switches to the box when in reverse and is still working fine).

-Disconnected the battery for 20 minutes and reconnected, no change.

-Measured the voltage at the charging point under hood and it shows about 12.22v which sounds like its a bit low so I stuck it back on the tender again.

-Checked the Amplifier area for any signs of moisture that could lead to a short, looks dry and clean (and there was no water exposed to the car for a while)

It doesn't look like the controller has a specific fuse associated with it, but I'll give that a look next.

I tried looking up the pinup for the iDrive controller and it looks like pin 1-2 are 12v/ground and I didn't get any signal on those from the meter (need to look where those connections come from next), but pin 3/4 which should be the CAN lines were giving me some voltage.

Help me dig out of this rabbit hole before my wife keeps telling me "this is why you should've leased!"
Any other ideas for diagnosis?

[PACarGuy]

Hmm, this is a tough one. Not sure if the controller is on a separate fuse (doubtful), but I would try that route first as well. When I changed my battery a couple of years ago I blew the fuse for the instrument cluster and I think something else too, and had to hunt them down and replace them. Unfortunately, as you know, the fuse diagram isn't exactly the most precise...you'll have to pull a few from the radio/head unit category and see if any are shot.

EDIT: also found this thread: https://www.e90post.com/forums/showthread.php?t=1394069

[Cyberdemon]

Originally Posted by PACarGuy

Hmm, this is a tough one. Not sure if the controller is on a separate fuse (doubtful), but I would try that route first as well. When I changed my battery a couple of years ago I blew the fuse for the instrument cluster and I think something else too, and had to hunt them down and replace them. Unfortunately, as you know, the fuse diagram isn't exactly the most precise...you'll have to pull a few from the radio/head unit category and see if any are shot.

EDIT: also found this thread: https://www.e90post.com/forums/showthread.php?t=1394069

I just pulled almost every fuse I could see in the radio category, all looked good.

The IDrive didn't appear to be getting 12v, so I have the car sitting on the tender to top off the battery. It may just still be a bit low even though it's new. I drove for about 20 min yesterday to try to give it some charge but I'll try to get it to 100% and try again.

I suppose that might roll out the controller itself but now I need to dig into the diagrams to figure out where that 12v on the IDrive harness goes.

My tender is slow so I'll probably have to check tomorrow and let it sit overnight. Will check to see if the battery is giving better voltage then.

[Bubbles]

Originally Posted by Cyberdemon

I just pulled almost every fuse I could see in the radio category, all looked good.

The IDrive didn't appear to be getting 12v, so I have the car sitting on the tender to top off the battery. It may just still be a bit low even though it's new. I drove for about 20 min yesterday to try to give it some charge but I'll try to get it to 100% and try again.

I suppose that might roll out the controller itself but now I need to dig into the diagrams to figure out where that 12v on the IDrive harness goes.

My tender is slow so I'll probably have to check tomorrow and let it sit overnight. Will check to see if the battery is giving better voltage then.

If that doesn’t work, code your car back to normal pre-CarPlay and see if that works. Make sure you have adequate voltage. When I was troubleshooting my backup camera I coded out rear backup light checks and it cause the front angel eyes to got out - strange (not immediately but after a few drives). I reverted the coding to stock and the angels eyes came back. I believe there is a counter for modules that will fail safe off in too many error occur within a period of time. You have to reset that counter to get it active again.
I have two errors that remain that do not appear to impact performance.

Checked for fault codes (Reingold/ISTA used) after the install (cleared) and the following faults remain:
S 0063 No communication possible with Amplifier
S 0112 No communication possible with ULF-SBX-H

I believe the “s” indicates coding/programming will not be possible.
Good luck.

[Cyberdemon]

Left the battery on the tender and got it up to 13V. Started the car and no surprise changes, but I tested the iDrive connector now and it is registering 12V to the controller on pin 1 & 2. I pulled the codes again and still get no communication with controller, but now the no comm with amp has been replaced with no communication possible with MOST Gateway, S0376 - the LVDS error cleared itself.

I tried disconnecting the battery again and will report back in a bit. Trying to figure out if something in the MOST bus would stop the controller path when everything else seems like it's working OK?

[Cyberdemon]

No luck after disconnecting the battery. I pulled the controller apart and it looks fine so I'm out of ideas other than replacing this or at least replacing the pcb, but how this got fried is beyond me.

[Bubbles]

Originally Posted by Cyberdemon

No luck after disconnecting the battery. I pulled the controller apart and it looks fine so I'm out of ideas other than replacing this or at least replacing the pcb, but how this got fried is beyond me.

Weird. Good news is used controllers can be had cheap on eBay.

[Cyberdemon]

I was getting a bunch of MOST errors randomly so I tried disconnecting the carplay box entirely just to rule that out as a possible issue, but to no avail. It resolved the mystery codes with the amp/headunit but controller is still borked.

I'm down to just the controller error and ISTA has no other diagnostic tests other than checking the pins.

The ones on ebay are all totally beat to shit for $200, so now I'm debating is it worth buying another potentially faulty one for $200 to take apart myself or just spend $420+ to get a guaranteed one from FCP Euro. Aren't even any for sale locally that I could buy just to test if this fixed it.

[Cyberdemon]

Disassembled my entire iDrive controller, there's no evidence of anything wrong and I was able to confirm 12V coming into the board so no bad solder joints or anything, something on the controller just seems screwed.

Now to buy a new one and hope it doesn't send me down a coding rat hole since it says new controllers need to be programmed.

[Bubbles]

Originally Posted by Cyberdemon

I was getting a bunch of MOST errors randomly so I tried disconnecting the carplay box entirely just to rule that out as a possible issue, but to no avail. It resolved the mystery codes with the amp/headunit but controller is still borked.

I'm down to just the controller error and ISTA has no other diagnostic tests other than checking the pins.

The ones on ebay are all totally beat to shit for $200, so now I'm debating is it worth buying another potentially faulty one for $200 to take apart myself or just spend $420+ to get a guaranteed one from FCP Euro. Aren't even any for sale locally that I could buy just to test if this fixed it.

Originally Posted by Cyberdemon

Disassembled my entire iDrive controller, there's no evidence of anything wrong and I was able to confirm 12V coming into the board so no bad solder joints or anything, something on the controller just seems screwed.

Now to buy a new one and hope it doesn't send me down a coding rat hole since it says new controllers need to be programmed.

I bought a used controller for 40$ and it did not require coding to operate. I swapped it for an old one that was cosmetically beat up. I can’t find the damn thing otherwise I would send it to you to hold you over.

[Cyberdemon]

Originally Posted by Bubbles

I bought a used controller for 40$ and it did not require coding to operate. I swapped it for an old one that was cosmetically beat up. I can’t find the damn thing otherwise I would send it to you to hold you over.

Thanks, managed to find one used for $75 just need to wait for it to show up. Will probably mush the two controllers together for whichever parts are cleanest. I've read some people had issues with it working based on the software version of the controller (since there were several newer part numbers that looked the same), but this one is an identical part number so hopefully it'll be a drop in.

[Cyberdemon]

Final outcome was the controller just fried. Replaced it with a board from the same part number and it works again. Most likely getting a shadow code about it not being programmed but I'll live with that.

How the car manages to damage a sensitive electronic on a battery change is another disappointing story I'm not sure how to answer though.

[bighindu79]

Originally Posted by Cyberdemon

Final outcome was the controller just fried. Replaced it with a board from the same part number and it works again. Most likely getting a shadow code about it not being programmed but I'll live with that.

How the car manages to damage a sensitive electronic on a battery change is another disappointing story I'm not sure how to answer though.

Battery changes can introduce the risk of frying circuits. When I replaced my battery two years ago, I made sure I disconnected the negative terminal first , then wrap the end in electrical tape and zip tie it to a body panel (same steps for the positive terminal) to ensure it didn't come in contact with anything to cause a short circuit while I was working. Then I did the reverse by connecting the positive terminal first followed by the negative terminal. No issues and the only thing I had to do was reset the time and date.

[Cyberdemon]

Originally Posted by bighindu79

Battery changes can introduce the risk of frying circuits. When I replaced my battery two years ago, I made sure I disconnected the negative terminal first , then wrap the end in electrical tape and zip tie it to a body panel (same steps for the positive terminal) to ensure it didn't come in contact with anything to cause a short circuit while I was working. Then I did the reverse by connecting the positive terminal first followed by the negative terminal. No issues and the only thing I had to do was reset the time and date.

Yeah that wasn't an issue here. I don't know if somehow breaking the IBS connector could have been linked to this in any way, but either way the fuses should've protected it. Clearly this has happened to a number of others so something was funky with the design of the IDrive circuitry.

[akkando]

Originally Posted by Cyberdemon

Yeah that wasn't an issue here. I don't know if somehow breaking the IBS connector could have been linked to this in any way, but either way the fuses should've protected it. Clearly this has happened to a number of others so something was funky with the design of the IDrive circuitry.

Is it possible the Carsara box wiring played a roll in this during battery change?

[Cyberdemon]

Originally Posted by akkando

Is it possible the Carsara box wiring played a roll in this during battery change?

It's unlikely only because there are a number of other folks who complained about this issue long before CarPlay boxes. I also didn't use the IDrive harness so there was no unique link between the two the wiring still runs through the original harness.

[Bubbles]

Originally Posted by Cyberdemon

Final outcome was the controller just fried. Replaced it with a board from the same part number and it works again. Most likely getting a shadow code about it not being programmed but I'll live with that.

How the car manages to damage a sensitive electronic on a battery change is another disappointing story I'm not sure how to answer though.

Good you got it resolved, in some cases INPA can clear stubborn codes that other platforms can’t.

[nyc4runnin]

Originally Posted by Cyberdemon

Thanks, managed to find one used for $75 just need to wait for it to show up. Will probably mush the two controllers together for whichever parts are cleanest. I've read some people had issues with it working based on the software version of the controller (since there were several newer part numbers that looked the same), but this one is an identical part number so hopefully it'll be a drop in.

where did you find a unit for $75 ? im in the same boat, CIC headunit died randomly...

[Cyberdemon]

Originally Posted by nyc4runnin

where did you find a unit for $75 ? im in the same boat, CIC headunit died randomly...

I posted a wanted ad in the FB group. Had a couple people respond and found the least awful one I could find. Looked like it had some weird liquid stains but I swapped my buttons over and just kept the internals so it worked out fine.

[MPower7]

Very helpful thread. Tried to use a battery box to start a car with dead battery then changed the battery. After battery swap idrive controller is no longer working. Is that a particular part number that we need to buy or can any CIC controller work on the e9x m3? I'm hearing about different pin types and don't want to buy the wrong one.

[Cyberdemon]

Originally Posted by MPower7

Very helpful thread. Tried to use a battery box to start a car with dead battery then changed the battery. After battery swap idrive controller is no longer working. Is that a particular part number that we need to buy or can any CIC controller work on the e9x m3? I'm hearing about different pin types and don't want to buy the wrong one.

There were a few variations, look at the part number on your controller and look for something with a matching PN if you can find it.