Engine wouldn't shut off

My first thought is there's some mechanical problem with the power button, something hanging up. Does it feel normal? Try pressing repeatedly, at different angles.

 

....and with that lack of detail and information, I'm clueless too....

But yeah....the machine is designed to turn off. If yours isn't...pursue it with the service department until you find an answer.

 

how long has it been running? does it turn on and off like normal, or does the engine not stop at all? did it shut down when you ran out of gas? did you try disconnecting the 12v battery? how was the battery charge indicator behaving during said problem? you might have hv battery issue.

btw, welcome to priuschat!

 

Can you be more specific. Were you stopped, in drive or park etc. The reason I am asking the start/stop button does different things depending on the conditions when it is pushed.

 

Did you try holding it for a few seconds?

 

You may have a bad display module. Power button is part of the problem, Toyota has extended the warranty on this part. Especially if the problem is repeatable. I carry my 2008 Prius notification in the glove box, you probably got one also but may not have paid attention. Nevertheless, the dealer can look it up.

Update: The TSB 0172-09 is attached. Here's a link to a Combination Meter thread.

 

I agree with rjparker, although the part in question, subject of the warantee extension, is more properly called the "Combination Meter", and the thing fails in all sorts of ways. Not turning off is one of them.

 

and yet, the dealer was clueless. how sad.

 

I have a 2004 prius and does the same problem. I read about combination meter. And I go to ebay, to repair it. It cost about 150 dollar. I replace and solve the problem.

How to replace: On step 15 don't forget to remove to bolt that hold air bag. I am not read it carefully and almost give up.
gen ii prius - combination meter removal
ingineerix.com/cmremoval/

 

I've had this happen on three occasions to my 2005. In all three cases I was able to power down after about 5 minutes. It hasn't happened in years. I figured one of the software updates took care of it. If its hardware then its extremely intermittent in my case.