Very Strang Electrical/Battery Issue

[recentfuture]

Fellow Enthusiasts,

Picked up a 2008 last year and I have been in the process of completely resuscitating this M3. Any and everything has been replaced/upgraded/repaired. Except the battery. Alternator/Ground Cable/Junction box all replaced. My car has died on me in the middle of driving 3 times since completing the restoration. All three times I've gotten clusters lights for ABS and idrive notification for brake failure. Oddly enough the driver side window controls for windows and mirrors doesn't work. Replaced the piece with dealer oem part, still no good. Replaced the footwell module - still no dice. The alarm doesn't engage when locking the car, the stereo (sound) doesn't work. Could all of these minor electrical issues be related to a bigger issue which causes the errors and subsequent shut down during driving? Has anyone ever experienced anything like this? I got the car for a steal but im in the hole for quite a bit after upgrades made to the vehicle. Any and all helpful comments/tips are appreciated.

[Redd]

Ok I'll ask the obvious question - why haven't you replaced the battery?

[DrFerry]

Flood damaged?

[recentfuture]

Originally Posted by Redd

Ok I'll ask the obvious question - why haven't you replaced the battery?

I intend to this week. Car drives and runs strong when this doesn't happen so I'm not sure if that correlates. Still doesn't give me a reason for why half the electronics in the car work and stuff like the alarm and radio don't.

[DrFerry]

I suggest measuring the voltage across the battery using the under hood terminals. If the steady state voltage at rest with motor off is less than ~12.8V strange codes, and behavior happen - such as the clock running slow or "increased emissions" warnings. A healthy AGM battery reading is about 13.3V. There's many threads out there on E9X battery gremlins.
.

[Redd]

I've recently been troubleshooting voltage issues which I have narrowed down to the Intelligent Battery Sensor (IBS). It was causing weird battery discharge problems. After I disconnected the IBS, I've been getting the full 14v from the alternator and no more discharge problems.

You can try to disconnect the IBS and see if it helps. It's the small blue connector on the negative battery cable. If disconnecting the IBS fixes your problem then you might need to replace the IBS.

[recentfuture]

Originally Posted by DrFerry

I suggest measuring the voltage across the battery using the under hood terminals. If the steady state voltage at rest with motor off is less than ~12.8V strange codes, and behavior happen - such as the clock running slow or "increased emissions" warnings. A healthy AGM battery reading is about 13.3V. There's many threads out there on E9X battery gremlins.
.

Voltage came back at 12.2 - also noticed the time in the cluster double blank. Thought that was weird. Indy diagnosed as alternator. Apparently BMW billed me for alternator swap but it didn't actually happen.

[recentfuture]

Originally Posted by Redd

I've recently been troubleshooting voltage issues which I have narrowed down to the Intelligent Battery Sensor (IBS). It was causing weird battery discharge problems. After I disconnected the IBS, I've been getting the full 14v from the alternator and no more discharge problems.

You can try to disconnect the IBS and see if it helps. It's the small blue connector on the negative battery cable. If disconnecting the IBS fixes your problem then you might need to replace the IBS.

If alternator isn't the solution this will be the next move, hopefully won't be necessary.

[Redd]

Originally Posted by recentfuture

If alternator isn't the solution this will be the next move, hopefully won't be necessary.

Just unplug the IBS first. It's one little blue connector attached to the battery negative cable. You will instantly be able to read full alternator 14v. If you aren't getting 14v with the IBS disconnected then it might be the alt.

[PACarGuy]

Originally Posted by Redd

Ok I'll ask the obvious question - why haven't you replaced the battery?

Would definitely second this. Over the last year or so had an intermittent red lift icon show up on my instrument cluster when I opened the door and an occasional K-CAN fault that would go away after clearing. Car drove fine with no other real symptoms.
Then yesterday I got the red lift icon and accompanying CC-ID 207 error (Central Electronics Failure ) after start up, and even though the car started and ran fine, I had the DSC, ABS, and Brake lights on in my dash. Only fault that came up on codes was Instrument Cluster, which I was able to clear. Then no DTC codes came up with Carly but the CC-ID 207 warning persisted. I had changed my battery to an Autocraft AGM with proper CCA from Autozone in October 2018 and figured my battery should be fine after less than four years. I even checked the voltage at the terminals and got 13.3V. Welp, per the suggestion of my Indy and after reviewing many thread forums, I decided to try a new battery to see if it would help. Coughed up the money at the dealer and installed it today. No more Central Electronics Failure and no more warning lights on the instrument cluster.
These cars are clearly very sensitive to bad or weak batteries and perhaps to non quality brands (though I thought the Autocraft brand was decent).


EDIT (Mar 2023): I was still getting occasional red car on a lift when I open the door but haven’t had the other issues recur yet, and no other error codes showing up. I have suspected a module somewhere is causing my issue, perhaps the JBE module, but my indy couldn't reproduce it or get any other codes to show up other than an LVDS break error (due to my Carplay unit that I installed, which has had that error since 2019 when I installed it). They did notice, however, that the battery was not actually registered to the car, even though I did that using Carly...or so I thought! They registered it using ISTA. Maybe that will fix my issue...

[recentfuture]

Alternator was the issue. Swapped alternator was a lemon. Purchased OEM from dealer and poof problem solved. I now have a MOST Bus issue as I have lost nav ability and audio in the vehicle. Sigh.

[Thumbie]

Originally Posted by PACarGuy

They did notice, however, that the battery was not actually registered to the car, even though I did that using Carly...or so I thought! They registered it using ISTA. Maybe that will fix my issue...

Did that fix the issue? I installed mr12volt and am getting the same symptoms you are. I replaced battery and registered via Bimmercode (or so I thought) but that changed nothing.

[spammysammich]

BimmerLink works correctly to register batteries. He stated that he needed a new oem battery.

[PACarGuy]

Originally Posted by Thumbie

Did that fix the issue? I installed mr12volt and am getting the same symptoms you are. I replaced battery and registered via Bimmercode (or so I thought) but that changed nothing.

Sorry to miss this. No, I still have the issue occasionally, but it doesn't seem to affect anything. I'm chalking it up to the Carplay box causing some breaks in the CAN or something like that. My indy suggested removing the CP box to see if it changes anything, but I like the functionality and it doesn't seem to impact anything at all.

[Thumbie]

Originally Posted by PACarGuy

Sorry to miss this. No, I still have the issue occasionally, but it doesn't seem to affect anything. I'm chalking it up to the Carplay box causing some breaks in the CAN or something like that. My indy suggested removing the CP box to see if it changes anything, but I like the functionality and it doesn't seem to impact anything at all.

No worries.

My problem actually just stopped one day almost a year ago and never came back haha.