Error message--park and brake

It may be a lower than normal voltage from the auxiliary battery.
I had exactly the same message while waiting at a drive-up window at a bank a couple years ago.

My eventual solution was to replace that battery. I've seen elsewhere that it can go bad (not take a charge).

There are other threads on PC that address this issue.

 

Jack,

The cryptic message about "the brake being engaged and that I should
try putting it in Park again when I was on level ground," is often an
indirect indicator of a weak 12V battery.

Do you have a way to check the voltage after it sits overnight?
It should be reading 12.5V or better, preferably at or above 13.0V.

Service life on the battery is ~4 years. However, if you ever had to
jump start the car, a near-complete discharge really diminishes the
capacity of the battery to hold a charge and leads to reduced service
life.

Have you noticed dimmed headlights or interior light with the car in
the Acc mode? -- brake pedal not depressed, two pushes of Power
button. that would point clearly to the 12V battery on its way out.

 

See the following for the built-in battery test procedure:
http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html

 

My prius had a similar strange message pop up on the screen..the touch screen says Warning and has 3 icons one showing PS, the second showing a battery and the 3rd showing a car with an exclamation mark.
The battery is fairly new but we have had an extremely cold last few days. I only bought the prius second hand about 2 months ago so I am unsure of what this message means...HELP!!

 

Usually one of the MFD icons will be lit more than the other two. Pls see which icon that is and post.

 

the car with the exclamation mark is the icon most lit up.

 

This means that the hybrid system has a problem. Are any other warning lights on? Any driveability symptoms?

The DTC needs to be read so you'll have a clue about the car's problem. Good luck.