January 2024 Cold Snap 2021 Model 3 Completely Bricked

[russw]

There's too much PII to just upload the invoice. But I've copied the important stuff below.

Repair Notes: Diagnosed and Replaced Pyrotechnic Battery Disconnect. Replaced 12V Battery.Replaced Rear Drive Unit Inverter.We confirmed the customers concern. We then removed and replaced the rear inverter as well asthe other parts listed above in accordance with the Tesla service manual. We took the vehicle on atest drive to observe and verify normal operation.Correction: Diagnosis: High Voltage Circuit Integrity CheckCorrection: Pyrotechnic Battery Disconnect (Remove & Replace) - Remove and Replace Parts Replaced or AddedPartQuantityHIGH VOLTAGEBATTERY -PYROTECHNICDISCONNECT -ASSEMBLY(1064689-00-J)1.00Correction: Battery - 12V (Lead Acid) (Remove & Replace) - Remove and Replace Parts Replaced or AddedPartQuantityASSEMBLY - 12VBATTERY AND VENTPLUG(1129182-00-B)1.00Correction: Inverter - Rear Drive Unit (3DU) (Remove & Replace) - Remove and Replace Parts Replaced or AddedPartQuantityBOLT AND WASHERM6X22(1112246-00-A)3.00BOLT, TE,M10X1.5X75.2,STL[109],ZNNI+WAX.(1111864-00-B)3.00BOLT M6-1.0X23(1100020-00-A)12.00LABEL-COVER-ACCESS-LUG-PHASE(1096344-00-C)1.00DRIVE INVERTER ASSEMBLY-REAR 3DU- HIGHCURRENT- TWOPHASE OPEN(1079924-17-L)1.00BOLT,PF,M6x12,2.00

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Same thing happened to my 2022 M3LR last week. 25K miles on it, in SF Bay Area so no extreme temperatures. I got out of the car and the pyro fuse blew (you can hear the pop).Threw lots of errors and wouldn't drive after that. Had driven it about 15 miles to the location it died. It had been 8 hours or so since I charged it to 80% at home (charges at 11Kwh) that morning. Wasn't particularly cold (50 degrees F?).
The interesting bit is that they also replaced my 12V battery in addition to the rear motor inverter, same as above. They said that when the fuse blows it protects the HV battery but not the 12v battery. Seems odd, but ok, must be a technical reason for that.
The service center said the failure is very rare.

 

[Tronguy]

Same thing happened to my 2022 M3LR last week. 25K miles on it, in SF Bay Area so no extreme temperatures. I got out of the car and the pyro fuse blew (you can hear the pop).Threw lots of errors and wouldn't drive after that. Had driven it about 15 miles to the location it died. It had been 8 hours or so since I charged it to 80% at home (charges at 11Kwh) that morning. Wasn't particularly cold (50 degrees F?).
The interesting bit is that they also replaced my 12V battery in addition to the rear motor inverter, same as above. They said that when the fuse blows it protects the HV battery but not the 12v battery. Seems odd, but ok, must be a technical reason for that.
The service center said the failure is very rare.

Oddly enough, the 2018 M3 LR RWD that the SO and I drove around from 9/2018 had that happen to it in mid 2019. The SO got in, tried to drive it out of the garage, and, wowzers, all the alarms lit up at once.

Called it into Tesla; they sent a tow truck. The driver tried jumping the car, no dice. Somehow got it out of gear (or maybe just dragged it out of the garage?) and got it up on the flatbed, then off it and the SO went to the local Service Center.

After a couple of days of waiting for the troubleshooter to free up, they gave us a Model S loaner and told us Evil Things had happened. It took several more days to get the car fixed, some of that waiting for parts to be shipped from California!

The repair bill cited the Pyro Fuse, the Pagoda Wiring Harness, and the 12V battery. The reason for the battery is fairly straightforward: It's a 12V battery and it's not getting charged and, essentially, runs itself flat.

A fully discharged lead-acid 12V battery tends to get itself damaged. The six cells in it, due to random numbers and manufacturing variations, don't carry equal charge. So, when getting discharged all the way down like this, the weaker cells run out of charge and the voltage across them reverses. Even if the battery recovers from this, the weak cells really don't come all the way back and the battery is likely to fail soon. And a non-recovering battery often has one or more cells that don't work, so, instead of having a 12V battery, one has a 10V, or 8V battery, and, well, that's that.

My conclusion was that some wire or other in the Pagoda area managed to short itself out to ground, probably due to bad laying out in the factory. The Pyro fuse is a "pyro" because, when it opens up, it blasts a non-conductive gas across the burned-out part of the fuse so one doesn't get an arc started. Not that important, say, at 12V or even 120 VAC, but a pretty big deal with the several hundred volts in the battery pack.

 

[russw]

Oddly enough, the 2018 M3 LR RWD that the SO and I drove around from 9/2018 had that happen to it in mid 2019. The SO got in, tried to drive it out of the garage, and, wowzers, all the alarms lit up at once.

Called it into Tesla; they sent a tow truck. The driver tried jumping the car, no dice. Somehow got it out of gear (or maybe just dragged it out of the garage?) and got it up on the flatbed, then off it and the SO went to the local Service Center.

After a couple of days of waiting for the troubleshooter to free up, they gave us a Model S loaner and told us Evil Things had happened. It took several more days to get the car fixed, some of that waiting for parts to be shipped from California!

The repair bill cited the Pyro Fuse, the Pagoda Wiring Harness, and the 12V battery. The reason for the battery is fairly straightforward: It's a 12V battery and it's not getting charged and, essentially, runs itself flat.

A fully discharged lead-acid 12V battery tends to get itself damaged. The six cells in it, due to random numbers and manufacturing variations, don't carry equal charge. So, when getting discharged all the way down like this, the weaker cells run out of charge and the voltage across them reverses. Even if the battery recovers from this, the weak cells really don't come all the way back and the battery is likely to fail soon. And a non-recovering battery often has one or more cells that don't work, so, instead of having a 12V battery, one has a 10V, or 8V battery, and, well, that's that.

My conclusion was that some wire or other in the Pagoda area managed to short itself out to ground, probably due to bad laying out in the factory. The Pyro fuse is a "pyro" because, when it opens up, it blasts a non-conductive gas across the burned-out part of the fuse so one doesn't get an arc started. Not that important, say, at 12V or even 120 VAC, but a pretty big deal with the several hundred volts in the battery pack.

Interesting about the 12v, makes sense, thanks. Also good info about the Pyro fuse.

I'm hoping the new inverter has some improvement in it that will help prevent future failures. There was a recall in China for these M3 rear inverters. The recall was up to Jan 2022 production and the recall was after that. My car was a Dec 2021 build.