Drivetrain Malfunction error 2014 REX

Hi everyone, first post :) Thanks for hosting this dedicated forum! Done some hunting around on this topic before I posted. Seems like this is an issue for the early model i3's unfortunately! Mine is a 2014 with 51k miles, I'm in central California. This error message came up a few times last week so I had the dealer diagnose it, and there assessment was replacing the high voltage cable to the tune of $1800. Still shooting codes after that replacement. Now they thinks its a module that has gone bad communicating between the HV system and the battery, which they want to replace for $4300. Youch! I love my i3, but I bought it used 3 years ago and at this point its only worth maybe 13k? It still drives, but gives me the error code every turn on.

So I took it to another regular repair shop for a second opinion, who was kind enough and sent me the diagnostic codes posted below. They sent me screen shoots with a bit more info also, but I can't seem to attach them here. They were clear they couldn't repair anything at this level of issue, as they don't have the more in depth tools for analysis and reprogramming. I'll list them below. Any insight from you techies based on this. I can't afford to sink this level of money in while the dealer seems to be guessing and just replacing very expensive parts and labor. Thanks in advance,

Gabriel

DME
"21E96F - Motor pool ACC to driver requirement not producible"

ELECTRIC MOTOR CONTROLS: CONVENIENCE CHARGING ELECTRONICS
"21E60A - Electronics charger: DSP active discharge of open circuit failure

ELECTRONIC MOTGOR CONTROLS: ELECTRICAL MACHIN ELECTRONICS
"222849 - Charge management function: Stationary cooling not possible"
"222825H/2238501 - Refer to OEM repair information for code description"
"222826 - Charge management function: Check control message 885, Charging with reduced output"
"2228DB - Information emergency running manager: low state of charge of the high voltage battery"
"2228B8 - Information emergency running manager, engine ECU: unable to activate driving readiness"


OBD2
"P1C70 - Manufacturer specific" unable to find description

Is the AC working properly? I mean do you get cool air if you turn AC on?

Yes, AC is working fine

Hello Bodygarden, it's always a good thing to have new posters here, so thanks for joining!

If my math is right, you bought your i3 in 2020? Is it a BEV or a REx?

Thanks for the welcome! Yes, probably 2019. Its a REX model

I noticed on some posts people replacing the 12v battery, could that have anything to do with it?

If car is on original 12v battery, then yes go ahead and replace. It’s low cost in the scheme of things. You do need to code on installation, but garage with ISTA software can do it, or you can do yourself with right kit.

spartacus68 said:

If car is on original 12v battery, then yes go ahead and replace. It’s low cost in the scheme of things. You do need to code on installation, but garage with ISTA software can do it, or you can do yourself with right kit.

Click to expand...

I don't know what registering a new 12 V battery does on an i3, so I'm not an authority on this matter.

A certified BMW i mechanic in a Facebook i3 group claims that i3 battery registration only records the installation date, the battery type, and the battery capacity but doesn't affect the charging behavior or the longevity of the battery. On BMW's ICE vehicles, registration apparently alters the alternator's charging behavior based on the battery's age and other factors. Modern BMW ICE vehicles might turn off their alternators at times to improve fuel efficiency. Their battery's condition might determine when and for how long their alternators could be turned off.

With no alternator, it makes sense that i3 battery registration might not affect the battery's longevity. Several i3 owners have reported installing new 12 V batteries without registering them. I'm not aware of any reports that failure to register has decreased a battery's longevity. However, that's not easy to determine.

Bodygarden, don't hesitate replacing the 12 V battery if you aren't able to register the battery. You could always register it later if you think doing so is worthwhile. For what it's worth, I registered a replacement battery in our former 2014 i3 just because I happened to own an OBD scanner that could do it. The BimmerLink smartphone app can also register a battery.

Thanks Sparatus and Art! Yes, its still on its original 12v battery. Is there any indication that all these drivetrain errors could be due to the low/poor battery though? I'm open to replacing it if there is probability it could be associated, just didn't want to go guessing at replacing things. Anything would be more affordable than what the dealer is telling me that I need to pay them another $4700 to replace a communication module that they think might be the issue?? Open to any alternatives to repair it another way. Thanks again,

Gabriel

Bodygarden said:

Yes, its still on its original 12v battery. Is there any indication that all these drivetrain errors could be due to the low/poor battery though? I'm open to replacing it if there is probability it could be associated, just didn't want to go guessing at replacing things. Anything would be more affordable than what the dealer is telling me that I need to pay them another $4700 to replace a communication module that they think might be the issue?? Open to any alternatives to repair it another way

Click to expand...

You might hold the record for 12 V battery longevity. It's really time to replace it before you're left stranded some day when the battery has insufficient power to start the car. Low 12 V system voltage can set all sorts of spurious DTC's which might explain what you're experiencing.

I can't believe the dealer wants to replace your 3G communications module which doesn't do anything now that 3G telephone service has been discontinued. The communications module is just sitting there consuming a bit of power trying to connect to a non-existent 3G signal but never succeeding.

Gotcha, should I order the factory replacement model battery? I'm guessing that would match whats in there?

The dealer is calling the module a communication module for lack of a better term. I don't think its the 3g communication module. I already replaced the high voltage cable. The 'module' in question somehow regulates or talk between the battery and the high voltage system is what I'm being told is the issue giving the drivetrain codes.

Bodygarden said:

Gotcha, should I order the factory replacement model battery? I'm guessing that would match whats in there?

Click to expand...

Order any AUX18L battery. Although some i3 owners have installed a less expensive power sports battery, ETX18L, it doesn't have common battery cell venting that connects to a vent tube at the right rear of the battery. Typically, buying a BMW-labeled battery would be more expensive even though all AUX18L batteries sold in the U.S. are manufactured by East Penn Manufacturing under various brands (e.g., Deka).

Bodygarden said:

The dealer is calling the module a communication module for lack of a better term. I don't think its the 3g communication module. I already replaced the high voltage cable. The 'module' in question somehow regulates or talk between the battery and the high voltage system is what I'm being told is the issue giving the drivetrain codes.

Click to expand...

That makes more sense. If there really is something wrong with this module, replacing the 12 V battery likely won't help. But who knows? It's time to replace the 12 V battery, and the cost isn't very high, so it's worth doing.

Just make sure to fully charge the replacement battery prior to installing it. Also, disconnect the high-voltage disconnect to the right of the frunk box prior to disconnecting the old battery. The reconnect it after installing the new battery. To be extra careful not to store DTC's, it's best to let the HV system go to sleep before disconnecting the HV disconnect. That typically takes ~30 minutes after doing anything that would awaken the HV system like unlocking the frunk, doors, or hatch.

Got the battery ordered, Well hope for the best with drivetrain function improvement. At least I won't stall out anytime soon in an inconvenient locale. Thanks for the install tips! I'll updated if anything miraculous resolves with the drivetrain. Thanks,

Gabriel

Did this get resolved and if yes what was the fix plesase? I have the same charging with reduced power fault code.