[KiwiME]

"40131 Found history code for cell voltage variation. Inspected cell voltages. No variance present. Likely due to cold weather. Cleared. "

If this were me I'd monitor and log the 98 cell group voltages while charging the traction battery. Use an OBD bluetooth dongle and Car Scanner. I'd guess you'll find one group consistently unstable.

 

[KiwiME]

I don't have any EV scanners tools.

These items are a trivial expense, the Car Scanner app works with either smartphone and is useful for any future EV. It might just take some patience watching while charging. But you can log the data as well and check it later.

What might be happening is that the BMS's voltage monitoring might be intermittently defective on one group and that's what's triggered a warning level. Somehow I recall this problem being reported before. It requires disassembly of the battery to repair.

I've marked the two items to watch with the yellow oval. If one cell group (of the 98) is faulty the number will be steady, identifying which one it is. You might also see the voltage variation show up momentarily in the graph at page 10. Generally a variation of 0.10 V across all the cells is a big problem. They should all be within 0.04, noting that the resolution is 0.02

 

[KiwiME]

There is information on the Car Scanner website regarding problems with "ELM327" dongles. The one I recommended works well but many others will too.