Lexus RX 450h 2012 Owner's Manual page 621

5-2. Steps to take in an emergency
Messages displayed when refueling
The following messages are displayed after the fuel filler door opener is
pressed. If the messages do not change or are displayed continuously,
have the vehicle checked by your Lexus dealer.
Message
620
Preparing the vehicle for refueling.
Wait a moment.
You may commence refueling.
Finish refueling within 30 minutes.
Close the fuel filler door.
Details