EPAS3P family
EPAS3P_a109_uiTuneReqCsError
Not Available
What does the EPAS3P_a109_uiTuneReqCsError alert mean?
Invalid UI_chassisControlChecksum value received
What you'll see in your Tesla
- Not Available
What triggers it
Unexpected UI_chassisControlChecksum value received
When it clears
Electronic Power Assist Steering (EPAS) recevies expected UI_chassisControlChecksum value
Potential impact
Reduced steering assist
Affected models
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.