[Daveyvtec]

Hi all, quick question. My 2020 330e threw a spanner light in the dash. I scanned it with BimmerLink and got the code 21F1C8 which BimmerLink tells me is HVS: Cell Monitoring, cell defect detected in module 6.

I had been driving for a while, a couple of hundred kilometers and used the onboard charger a couple of times during the day. Now the car won’t charge. BimmerLink will clear the code after a few tries but the light stays on the dash and still no charging.

Anyone familiar with this issue? I’m seeing some places saying it needs a software/firmware update, other saying a whole battery replacement! Any bit of guidance will do here. Thanks

[phiber]

Check out this video:

If it's not the module itself then it's the BMS of that module.
You'll need to get this fixed.