MyTeslaMate
BMS family

BMS_a131_Bleed_FET_Failure

Not Available

What does the BMS_a131_Bleed_FET_Failure alert mean?

A bleed Field-Effect Transistor (FET) on the Battery Management Board (BMB) is not operating as designed. This will prevent the battery from balancing the brick by decreasing the brick voltage.

What you'll see in your Tesla

  • Not Available

What triggers it

Upon a periodic wake, after an ECU reset, or every 6 hours, the Battery Management System (BMS) will test all bleed switches by switching them on in turn. If the sensed brick voltage does not significantly change, this alert is set.

When it clears

The bleed test reports sufficient voltage change across each brick.

Potential impact

The bleed FET will prevent the battery from properly balancing the brick by bleeding the voltage down. There is a decrease in available energy to the vehicle potentially leading to decreased range.

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.