STO family
STO_a104_mcuVoltFail
Not Available
What does the STO_a104_mcuVoltFail alert mean?
Steering Torque Overlay (STO) assist halted due to microcontroller voltage monitor startup failure.
What you'll see in your Tesla
- Not Available
What triggers it
Internal: microcontroller voltage monitor failure twice on startup
When it clears
System Reset
Potential impact
Steering Assist reduced
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.