Unable to charge - BMS_a063, BMS_a091, VCFRONT_a180, VCFRONT_a192

[Tarun Kumar P]

Hello All,

First time posting here (read it as never had the need to, everything I was looking for was already available - until now ).

Received a bunch of error codes in my 2018 M3LR last night:
BMS_a063 - Unable to charge, disconnect and retry
VCFRONT_a180 - Electrical system power reduced, vehicle may shut down unexpectedly
BMS_a091 - Unable to charge, Service is required
VCFRONT_a192 - Electrical system is unable to support all features, Switching off features to conserve energy.

Scenario: Got mobile notification software update will be installed tonight, so put the car for charging, schedule begins at 12 in the night.
Later in the night mobile app notifies there is an issue with charging.
Next morning I notice the circuit breaker of the EV charger is tripped, car hasn't charged even a single mile, charger is locked and unable to unlock --> had to manually unlock through the trunk.
Car shows a bunch of errors on the screen as listed above, unable to put the car in drive or reverse - doesn't let me drive .
Tried the s/w reboot and plugged in the charger to no luck.

Got it towed to the nearest Tesla dealership, car is sitting on their lot with all batteries dead. With holidays and backed up appointments, the earliest they will be able to take a look is sometime next week - so no real ETA .

Not sure if the software update finished or no, I can't even remember which version showed up on the first notification.

Needless to say, vehicle is out of warranty. Hoping its not anything major and doesn't make a huge dent to the pockets.

Q. Any idea of what is going on here? Anyone has seen these error codes at the time of software update?

 

[jjrandorin]

Have you ever replaced the 12 Volt low voltage battery?

 

[Tarun Kumar P]

Have you ever replaced the 12 Volt low voltage battery?

Oh yeah forgot to mention it. I got the 12v battery replaced in Sep 2023 from Tesla.

 

[nicksp]

Hello All,

First time posting here (read it as never had the need to, everything I was looking for was already available - until now ).

Received a bunch of error codes in my 2018 M3LR last night:
BMS_a063 - Unable to charge, disconnect and retry
VCFRONT_a180 - Electrical system power reduced, vehicle may shut down unexpectedly
BMS_a091 - Unable to charge, Service is required
VCFRONT_a192 - Electrical system is unable to support all features, Switching off features to conserve energy.

Scenario: Got mobile notification software update will be installed tonight, so put the car for charging, schedule begins at 12 in the night.
Later in the night mobile app notifies there is an issue with charging.
Next morning I notice the circuit breaker of the EV charger is tripped, car hasn't charged even a single mile, charger is locked and unable to unlock --> had to manually unlock through the trunk.
Car shows a bunch of errors on the screen as listed above, unable to put the car in drive or reverse - doesn't let me drive .
Tried the s/w reboot and plugged in the charger to no luck.

Got it towed to the nearest Tesla dealership, car is sitting on their lot with all batteries dead. With holidays and backed up appointments, the earliest they will be able to take a look is sometime next week - so no real ETA .

Not sure if the software update finished or no, I can't even remember which version showed up on the first notification.

Needless to say, vehicle is out of warranty. Hoping its not anything major and doesn't make a huge dent to the pockets.

Q. Any idea of what is going on here? Anyone has seen these error codes at the time of software update?


View attachment 1004224

What's the miles on your car? If it's the battery or the drive train, you should still have 2 more years left.

 

[Tarun Kumar P]

What's the miles on your car? If it's the battery or the drive train, you should still have 2 more years left.

Mileage isn’t too much, I am at around 43k miles. So yeah the drivetrain and battery are in warranty.

 

[Tarun Kumar P]

Update Day 2: To my surprise Tesla came back with an estimate today at just before 7am local time (I am sure they don't start work that early, but honestly not sure what to make out of the timing).

They need to replace the ASSEMBLY POWER CONVERSION SYSTEM - 48AMP - 1PHASE (1135558-04-A), the total cost including labor is close to $2K .

Have asked them if they know what happened to the PCS and what might have caused it?

Read a few other threads on the forum and replacement of the PCS seems very common (even in new cars) and the service centers seem to keep a good stock of these parts.

At this time, I am more concerned about what might have caused the issue, is any of it due to the AC line that I use at home, as I had noted earlier the circuit breaker had tripped when the incident occurred. Want to rule it out before I plug in the car after its back from repair. Wondering how do I do that.

 

[davewill]

Tell us more about your charging setup. What kind of EVSE, what size circuit, what rate you were charging at, etc... A PCS going bad doesn't really explain tripping the breaker, although I suppose it could cause that. Conversely, tripping the breaker shouldn't really toast the PCS, either. If we could figure out why the breaker tripped, it might be useful. I assume you were able to reset the breaker? Any way for you to test charging again?

 

[father_of_6]

I'm not quick to discount the software update process as a culprit either.

 

[Tarun Kumar P]

Tell us more about your charging setup. What kind of EVSE, what size circuit, what rate you were charging at, etc... A PCS going bad doesn't really explain tripping the breaker, although I suppose it could cause that. Conversely, tripping the breaker shouldn't really toast the PCS, either. If we could figure out why the breaker tripped, it might be useful. I assume you were able to reset the breaker? Any way for you to test charging again?

I use the mobile charger with a 14-50 NEMA outlet - has been working great for a long time. I was able to reset the breaker immediately and tried but the car wouldn't charge.

Latest Update: Tesla replaced the PCS and also the 12V low voltage battery, they charged my car at the service center using the super charger and it works fine. All error message are gone now. Got the car back, but I am still skeptical to put it in my 14-50 NEMA outlet (after burning $2K on the repairs).
The PCS has a 12 month or 12.5k Miles warranty, which gives me some relief, but haven't mustered the courage to plug it in yet.

I asked Tesla what went wrong and they said they don't know, at the same time they said think of PCS as wear and tear since it is constantly switching between different power sources and adjusting the charging levels! They mentioned they will be sending the PCS to engineering to diagnose what went wrong, but that is more from an internal process/troubleshooting and none of that will be available to me as a consumer.

I'm not quick to discount the software update process as a culprit either.

Agree, I too still think there was something that happened at the time of software update that might have caused this. Unfortunately no way to prove it.

Bottomline, you see any of these error codes and you are unable to charge most likely the PCS needs to be replaced.

 

[father_of_6]

PCS is not used for Supercharging.

 

[Tarun Kumar P]

PCS is not used for Supercharging.

Gosh! that means they wouldn't have actually tested the newly installed PCS .

 

[father_of_6]

Gosh! that means they wouldn't have actually tested the newly installed PCS .

I bet it's fine though, if that was the issue.

 

[KenC]

Reading this, the first thing I would look at is the 12v, but since that was changed in the Fall, then the PCS.

I'd have gone into the service menu and taken a look at a few of those screens to see more detailed info on what the errors might have been. Anyway, parts failing are always annoying if you don't get a satisfactory explanation of why they failed.