The Redundant Control Unit (RCU) power supply voltage is too high.
<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) power supply voltage is too high.
The RCU power supply voltage is higher than 18 volts for 2 seconds or higher than 19 volts for 500 milliseconds.
The RCU power supply voltage has returned below 17.5 volts.
Model Y 2025+
customer, service-fix
Sign up for Tessie. Try it free for 14 days. Happiness guaranteed.