REX starting but not charging - Loud fan noise when charging

FYI - have the car for 3+ years, this is the first time this happens. Its a 2014 i3 with REX. Never had a problem before. Just passed the 40k mile mark. Now the REX will start when battery charge is below 6.5% but won't stay on. DriveTrain error symbol is on, and display shows "Only electric drive possible. Limited driving range. Continued driving possible. Consult nearest service center." I made it home and plugged in the Level-2 charger, a loud fan noise in the front came on and stayed on the entire time it was charging. That is all new behavior. Never did this before.

I checked the trouble codes with a regular code reader and it displays these two codes: P1M50 and P0N91
Unfortunately, I don't have the software to see what these codes translate to and a google search came back empty.

I made a service appointment with BMW to have this checked out.
Has anybody experienced this as well? Is there a website or software available to translate these trouble codes by any chance?

For a car with less than 50k miles on it, these little 'issues' are sure concerning, especially once one has to start paying for it out of pocket when the short warranty for this experimental car is over. I love to drive this car but I sure wish BMW would keep extending the warranty to keep the experiment going ...

Fan noise may be cooling system for the battery. Mine has done that (cooling fan coming on) a few times. REx not charging is a different issue.

I had this problem about a month ago, 'Drivetrain error' and REX would not turn on. Did not check the OBD codes.

The dealer initially checked for a short in a REX module, when that tested ok, they replaced the wire harness. Have not had the fault since...

just to provide an update on what the dealer did to fix my particular issue: It was due to a faulty fuel-relay that made the REX starve for fuel. However, they could not find a cause for the loud fan noise and it didn't happen while it was at the dealer. I have it now charged twice at home since the service, and the loud fan has not kicked in again so far. So, I am crossing my fingers that it was somehow related and is a thing of the past as well. thank you for all your comments.

golli said:

However, they could not find a cause for the loud fan noise and it didn't happen while it was at the dealer.

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If this noise seems to be coming from the rear of the car, it's probably the A/C compressor which in addition to cooling the cabin, also cools the battery pack which could have been warm from driving in warm weather and from charging. This compressor can be quite loud.

If this noise seems to be coming from the front of the car, it's probably the fan cooling the radiator for the REx engine's coolant. I don't have a REx, so I don't know how loud this fan could be, but I doubt that it is nearly as loud as the A/C compressor.

@Golli,

Was it a relay inside the tank or somewhere else?

Thank you for your help as we are a couple here having the same issue without any gos reponse from dealer. My car has been to the dealer 3 times for a total of 12 hours without any success!!!

If you have any part number that could help us, that would be greatly appreciated.

alohart said:

golli said:

However, they could not find a cause for the loud fan noise and it didn't happen while it was at the dealer.

Click to expand...

If this noise seems to be coming from the rear of the car, it's probably the A/C compressor which in addition to cooling the cabin, also cools the battery pack which could have been warm from driving in warm weather and from charging. This compressor can be quite loud.

If this noise seems to be coming from the front of the car, it's probably the fan cooling the radiator for the REx engine's coolant. I don't have a REx, so I don't know how loud this fan could be, but I doubt that it is nearly as loud as the A/C compressor.

Click to expand...

Think Aloha is right - I have one i3 BEV and a i3 REX. The rex had the fan in front exchanged and the BEV had the climate compressor exchanged.
The compressor is more regular and noisy where the fan is a more quiet fan however noisier than the usual coolings sounds...