BMS family
BMS_a142_SW_Isolation_Degradation
Not Available
What does the BMS_a142_SW_Isolation_Degradation alert mean?
The battery management system (BMS) detects that the high voltage (HV) isolation contactor closed below the warning threshold.
What you'll see in your Tesla
- Not Available
What triggers it
The BMS detects that the HV isolation was below the warning threshold when pack contactors closed.
When it clears
The BMS detects that HV isolation is above the warning threshold when pack contactors closed.
Potential impact
This alert indicates that HV isolation is low, but above the sufficient level for vehicle operation.
Affected models
Model 3 2017-2023
Model 3 2024+
Model S 2021+
Model X 2021+
Model Y
Model Y 2025+
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.