BMS family
BMS_a027_SW_Repeated_Isolation_Failure_In_Drive
Power limited - OK to drive
What does the BMS_a027_SW_Repeated_Isolation_Failure_In_Drive alert mean?
High voltage isolation dropped under threshold in many drive sessions
What you'll see in your Tesla
- Power limited - OK to drive
- Vehicle may not restart after this drive
What triggers it
Isolation or isolation degradation alert is set many times
When it clears
Many drive sessions with no isolation or isolation degradation alerts
Potential impact
Vehicle will be unable to restart
Affected models
Model 3 2017-2023
Model 3 2024+
Model S 2021+
Model X 2021+
Model Y
Model Y 2025+
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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.