MyTeslaMate
STO family

STO_a005_pwrSup3V3Fail

Not Available

What does the STO_a005_pwrSup3V3Fail alert mean?

Steering Torque Overlay (STO) assist halted due to 3.3 Volt Power Supply failure.

What you'll see in your Tesla

  • Not Available

What triggers it

Internal: 3.3V Power Supply voltage >= 3.5 Volts or <= 3.09 Volts for 20ms

When it clears

System Reset

Potential impact

Steering Assist reduced

Affected models

Semitruck

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.