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BMS_u008 gives limp mode but car continues to drive

I'm asking this for a friend who has some issues with his Model S P85 from 11-2013. Car has 330.000km and has eaten 3 driveunits along the way, still on original battery but contactors are replaced with Innocell 7 years ago.

First he got a 12V battery warning and only a few days later he is getting error BMS_u008, we replaced the 12V battery and that error went away but BMS_u008 continued. Next thing we did was Google and see what comes up.

On Google I see a lot of fault codes combined with this same issue. i.e (BMS_w172 or DI_w062) but none of that is what happens here.

Also he has no range loss due to this error or other isolation errors that would shut HV (or the DC/DC) down. He can drive the car perfectly fine only supercharge, power and regen are nerfed.

Unfortunately we cannot enter Factory mode or use Toolbox since this is disabled after 2022.8 and he also has the MCU upgrade done, we could try to see if we can find something with scanmytesla but not sure if that will help us.

Does anybody have any idea what we can check to make sure only a complete battery replacement is left?


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