MyTeslaMate
IBST family

IBST_a093_UEXSOvertemperature

Power braking assist reduced

What does the IBST_a093_UEXSOvertemperature alert mean?

iBooster (IBST) detected an ECU output (UEXS) over-temperature condition and has been switched off.

What you'll see in your Tesla

  • Power braking assist reduced
  • Braking may require increased effort

What triggers it

UEXS has over-temperature and has been switched off.

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.