Had the red triangle twice now but it says 'no codes' in both autel scanner and torque pro. I've cut it off again now. Could it be anything to do with overheating in this hot weather?
Did it flash quickly then dissappear? Could be anything from low oil to intermitten inverter pump failure to an overheating engine... Start with checking your oil immediately. That is the place to start when seeing an intermittent red triangle flash with no code. Posted via the PriusChat mobile app.
Try Dr. Prius app... The two apps you mentioned don't read codes very accurately on Prius, especially sub-codes...