IBST family
IBST_a020_VPREU5VOutOfRange
Power braking assist reduced
What does the IBST_a020_VPREU5VOutOfRange alert mean?
iBooster (IBST) monitoring of voltage pre-charge (VPRE) U5V over and undervoltage bits has detected an out of range value.
What you'll see in your Tesla
- Power braking assist reduced
- Braking may require increased effort
What triggers it
IBST monitoring of VPRE U5V over and undervoltage bits detects an out of range value.
When it clears
iBooster can not recover from this condition. iBooster replacement may be required.
Potential impact
IBST may not operate as expected.
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.