BMS family
BMS_f027_SW_Drive_Iso_Repeated
Unable to start vehicle
What does the BMS_f027_SW_Drive_Iso_Repeated alert mean?
The battery management system (BMS) detects that there was a repeated loss of isolation during drive.
What you'll see in your Tesla
- Unable to start vehicle
- Service is required
What triggers it
The BMS detects that isolation dropped multiple times below the minimum threshold while driving.
When it clears
The BMS isolation counter undergoes a manual reset.
Potential impact
The vehicle will not start.
Affected models
Model S 2012-2020
Model X 2015-2020
Track your Tesla's alerts automatically
Alerts like this reach MyTeslaMate through your car's Tesla telemetry API. MyTeslaMate logs every alert your Tesla reports and turns it into readable history and real-time notifications — hosted TeslaMate with no server to run.