MyTeslaMate
BMS family

BMS_a049_SW_Thermal_Event

Shutdown - Pull over and exit vehicle safely

What does the BMS_a049_SW_Thermal_Event alert mean?

The battery management system (BMS) detects conditions that indicate a potential propagating thermal event.

What you'll see in your Tesla

  • Shutdown - Pull over and exit vehicle safely
  • Immediate service is required

What triggers it

At least one brick under/over voltage alert was recently active, and at least one isolation alert was recently active, and at least one battery monitoring board (BMB) missing (MIA) alert was recently active, and the max thermistor temp exceeds the limit, and the pack temperature gradient (maxTemp - minTemp) exceeds the threshold, and that gradient is increasing at a rate greater than the slop threshold.

When it clears

None. This alert clears upon BMS reset.

Potential impact

Indicates rapid temperature rise in conjunction with other critical alerts. Pack may remain inoperable and should be serviced according to proper procedures.

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.