RCU family
RCU_a015_fluidLeakDetected
Backup power braking assist unavailable
What does the RCU_a015_fluidLeakDetected alert mean?
The Redundant Control Unit (RCU) has detected a hydraulic brake fluid leak.
What you'll see in your Tesla
- Backup power braking assist unavailable
- OK to drive - Schedule service
What triggers it
The RCU detects an internal or external hydraulic brake fluid leak or detects air in the hydraulic system.
When it clears
The RCU no longer detects a hydraulic leakage or air after being power cycled.
Potential impact
The RCU may not be able to perform backup power braking assist.
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.