Check hybrid system and code p261b

I was driving and got this “check hybrid system” and lost powef. Pulled over and got the code P261B. Turned car off and set for a few mins and when I turned it back on the chech hybrid system was gone. I replaced the water pump but when I turn the car on now it says check hybrid system. I tried putting it in maintenance mode and can get the screen to say maintenance mode but then when I press the brake and start button it just turns off. This is a 2011 Prius with around 230,000 miles on it. Please help.

 

The only code it gives me is P261B.