About a week and a half ago my prius started giving me this problem. When I push the power button to shut the car off it will shut off and then come back on about 5 seconds later in the power mode where the radio comes on and you can roll down the windows. This problem causes my car to loose memory of the radio presets, clock and my trip A & B mileage. I don't know what the cause of this is, but it seems to be happening almost evertime I try and turn the car off now. Can anyone help?
yep! check your 12v battery connections first, that's your most likely culprit. make sure they're good and tight.
Or the 12V battery is drained for some reason (have you ever left the lights on, or a door or the hatch open all night, or something else to drain it?). Or the power button is faulty.