BMS_a027 error

[Qasim]

I have 2021 Model 3, after Recent update to 2022.28.1 I had this BMS_a027 fault. It says High voltage isolation dropped under threshold many drive sessions. I’ve seen these posts in Tesla Facebook groups which were the same issues after recent update to 2022.28.1
Strangely all post disease from Facebook now but I’ve screenshot.

 

[jjrandorin]

If this is not a salvage vehicle, take it to tesla.

 

[Qasim]

Someone just posted this

 

[Janet H]

I am having the same problem. The upgrade was done Sunday, and I now have three error messages: BMS_a170, BMS_a027 and DI_a201. Help?

 

[jjrandorin]

I am having the same problem. The upgrade was done Sunday, and I now have three error messages: BMS_a170, BMS_a027 and DI_a201. Help?

Same advice. If its not a salvage vehicle, take it to tesla.

 

[Beckasoup]

Ugh, saaaaaaame. Had to drive all the way to work with no Re-Gen braking. Rebooted twice to no avail. Putting in a ticket.

 

[Danielk9]

Same problem. Set up an appointment. Similar error happened a month ago and was “fixed” by replacing the inverter.

 

[David_PA]

Very helpful information. My Model 3 had a number of errors. After doing a soft reboot now have the BMS_a027 and BMS_a170 error as shown by DanielK9.

Any thoughts in respect to if it safe to drive the vehichle to a repair center (approximately 50 miles) with these errors?

 

[Danielk9]

I plan on driving 13 miles to my service center. The drivetrain warranty should cover it once it is there. This will be third time to the service center in a couple of months. First was a 12V battery issue, second was very similar error to this, and now this one.

 

[David_PA]

The only page I can find with the BMS_a027 and BMS_a170 error codes is this page and those reporting these errors got them around the same time. My errors occurred prior to the 2022.28.1 update. After the update the BMS_a170 error was gone. After a reset, the BMS_a170 error returned.

In my case I am trying to get my Model 3 towed as the trip to the service center is NJ highway.

 

[Danielk9]

So what happened is that the error was not cleared after the actual problem was fixed two months ago. At that point I had one of the errors (027) and was told not to drive the car. It was towed and the inverter was replaced. At that point they did not clear the error. But it was not user facing until this update, at which point it showed up. I drove to the service center and they had to connect physically to the car to clear it. Which they did. Car drives normally now. I’ll update you if anything changes.

 

[David_PA]

They will also be replacing the inverter in my vehicle and my car will be done late Monday afternoon, which is fast turnaround.

 

[Dzhama Omarov]

So what happened is that the error was not cleared after the actual problem was fixed two months ago. At that point I had one of the errors (027) and was told not to drive the car. It was towed and the inverter was replaced. At that point they did not clear the error. But it was not user facing until this update, at which point it showed up. I drove to the service center and they had to connect physically to the car to clear it. Which they did. Car drives normally now. I’ll update you if anything changes.

Am i Right to understand that you had errors BMS_a027 and BMS_a170 and then your inverter was replaced. After the replacement you had no errors, but after some time the errors returned due to not being cleared off?

 

[Danielk9]

Am i Right to understand that you had errors BMS_a027 and BMS_a170 and then your inverter was replaced. After the replacement you had no errors, but after some time the errors returned due to not being cleared off?

The errors returned after a software update because the update changed one of the errors to be user facing, rather than internal. That's what they said, anyway. They cleared the error in about half an hour and the car has been fine since. The errors DID appear after a software update.

 

[Dzhama Omarov]

The errors returned after a software update because the update changed one of the errors to be user facing, rather than internal. That's what they said, anyway. They cleared the error in about half an hour and the car has been fine since. The errors DID appear after a software update.

I see, thank you very much!)

 

[Tessie805]

Just updated to 2022.36.6 and after the reboot, i got errors BMS_a027 and BMS_a170.

Has anyone heard back from service? Do I really need to bring my car in? The closest service is 90 minutes away and if "speed is reduced" then I'll be driving on the highway at reduced speeds?

Is this an actual problem? Or software issue?

 

[Dzhama Omarov]

Just updated to 2022.36.6 and after the reboot, i got errors BMS_a027 and BMS_a170.

Has anyone heard back from service? Do I really need to bring my car in? The closest service is 90 minutes away and if "speed is reduced" then I'll be driving on the highway at reduced speeds?

Is this an actual problem? Or software issue?

Clearing the errors helped me, I’ve been driving for a week now, no signs of any error

 

[Dzhama Omarov]

Just updated to 2022.36.6 and after the reboot, i got errors BMS_a027 and BMS_a170.

Has anyone heard back from service? Do I really need to bring my car in? The closest service is 90 minutes away and if "speed is reduced" then I'll be driving on the highway at reduced speeds?

Is this an actual problem? Or software issue?

Have you had any motor/inverter replacements in your car?

 

[Tessie805]

Have you had any motor/inverter replacements in your car?

I haven't. It's just surprising that it comes up right after a software update.

I have a service appointment on Friday. They said this issue cannot be diagnosed with a mobile appointment. But since I have to drive 90 mins on a highway to get to it, I'm not sure how fast I can go on "limited power". Hopefully fast enough for highway driving.

 

[Tessie805]

Just updated to 2022.36.6 and after the reboot, i got errors BMS_a027 and BMS_a170.

Clearing the errors helped me, I’ve been driving for a week now, no signs of any error

How do you clear the errors?