CC family
CC_a020_3vRailIncorrect
Unable to charge - Wall Connector issue
What does the CC_a020_3vRailIncorrect alert mean?
Microcontroller supply rail is incorrect.
What you'll see in your Tesla
- Unable to charge - Wall Connector issue
- Wall Connector needs service
What triggers it
Microcontroller supply voltage is outside of valid range.
When it clears
Microcontroller supply voltage enters valid range.
Potential impact
Wall connector will not operate.
Affected models
Cybertruck
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.