long stick wedged from your console to the gas pedal.
Assuming no codes perhaps your driving with your foot rested on the brake?
Otherwise, I would begin investigating the brake switch that tells the cruise control your braking. Since I have not fiddled with that part of the car perhaps someone can clear up those details on how the prius knows your braking for cruise control. I’d be curious to know if your brakes flash intermittently while driving.
Hope these ideas help.
