BMSSEMI family
BMSSEMI_a087_SystemIsolation
High voltage system error detected
What does the BMSSEMI_a087_SystemIsolation alert mean?
High Voltage (HV) isolation is experiencing a fault condition.
What you'll see in your Tesla
- High voltage system error detected
- Vehicle may not restart - Service is required
What triggers it
HVPACKx_feimNeeded is true for at least one HVPACK.
When it clears
HVPACKx_feimNeeded is false for all HVPACKs.
Potential impact
Battery Management System (BMS) will exit the HV_UP state once vehicle is no longer in drive. The user will no longer be able to drive.
Affected models
Semitruck
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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.