EPAS3S family
EPAS3S_a147_backupVehSpeed
Not Available
What does the EPAS3S_a147_backupVehSpeed alert mean?
Electronic Power Assist Steering (EPAS) transition to DI vehicle speed source
What you'll see in your Tesla
- Not Available
What triggers it
ESP_wheelRotation missing or degraded ESP_wheelSpeedQF or degraded DI_speed backup vehicle speed message
When it clears
Electronic Power Assist Steering (EPAS) power cycle
Potential impact
Electronic Power Assist Steering (EPAS) is in reduced assist state, EAC is inhibited
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.