The Redundant Control Unit (RCU) Micro Controller Unit (MCU) has experienced an issue.
<0.01% (Extremely rare)
Backup power braking assist unavailable
OK to drive - Schedule service
The RCU may not be able to perform backup power braking assist.
The Redundant Control Unit (RCU) Micro Controller Unit (MCU) has experienced an issue.
The RCU microcontroller has a software, hardware, or power supply issue.
The microcontroller issue is no longer present after the RCU is power cycled. If the issue persists, the RCU may need to be replaced.
Model Y 2025+
customer, service-fix
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