MyTeslaMate
IDB family

IDB_a063_RCUactuationDLC

Backup power braking assist unavailable

What does the IDB_a063_RCUactuationDLC alert mean?

Redundant Control Unit (RCU) actuation message RCU_actuation was not received or message length is incorrect.

What you'll see in your Tesla

  • Backup power braking assist unavailable
  • OK to drive - Schedule service

What triggers it

RCU_actuation is not received for longer than 200 milliseconds or RCU_actuation is received with incorrect data length for longer than 200 milliseconds.

When it clears

RCU_actuation Controller Area Network (CAN) message is received with correct data length for 200 milliseconds.

Potential impact

There may be an issue with the transmitting Electronic Control Unit (ECU) or CAN bus.

Affected models

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.