PCS2 family
PCS2_a021_powerRailUnderVoltage
Not Available
What does the PCS2_a021_powerRailUnderVoltage alert mean?
The generated power rail (4.5V, 10V, or 18V) has gone lower than the allowed lower threshold
What you'll see in your Tesla
- Not Available
What triggers it
The power rail (4.5V, 10V or 18V) has gone lower than the allowed lower threshold
When it clears
The power rail (4.5V, 10V or 18V) returns above the allowed lower threshold
Potential impact
DCDC and AC Charging may be limited or unavailable.
Affected models
Model 3 2017-2023
Model 3 2024+
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.