PCS family
PCS_a104_ambientTempRationality
Not Available
What does the PCS_a104_ambientTempRationality alert mean?
PCS ambient temperature sensor is reporting an irrational value
What you'll see in your Tesla
- Not Available
What triggers it
Ambient temperature is outside of expected range for more than 1s
When it clears
Ambient temperature is within expected range
Potential impact
DCDC insufficient cooling check will be disabled if the ambient temp sensor is irrational
Affected models
Model 3 2017-2023
Model 3 2024+
Model S 2021+
Model X 2021+
Model Y
Model Y 2025+
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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.