Prius won't go into drive...

Sounds like she wasn't pressing hard enough on the brake pedal when she pushed the Start button. Common problem for some...

 

If you noticed in u-tub your ready light did not come on in the dash and the red light was on the start button! Green light will show on the start button when the ready light is on, Probably need a new 12V battery, Hal

 

With all due respect to your wife, if you can't reproduce the problem it was most likely operator error. Simple solution: *don't* shut the car OFF when waiting in it. Just leave it ON. If she/you tire of pressing the brake pedal, shift it to Park.

It would be prudent to check the 12V battery eliminate it as a contributor; it's easy and needs no tools:
http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html

Otherwise as noted above the brake pedal position sensor may be faulty or need adjusting.

 

I believe it is 51 AH if you have Smart key and 48AH with normal. H

 

Unintended dropping into neutral is disconcerting but alot of us do that routinely to clean the brake pads. Since Prius uses regen braking there's not alot of brake pressure used by the driver to stop the car hence the brake rotors up front tend to get rusted from lack of use. Look at yours and you'll see what I mean. Easy solution for cleaning is to get up to highway speed.....put the shifter into neutral which releases regen and apply steady and fairly firm repeated pressure to the brakes. Pump your brakes. Make sure no ones in front of you though as you'll be surprised how poor the brakes are without regen assist. And no one behind you as they'll think your crazy braking for nothing. When your done put the shifter back into D. I do it all the time at 60-70 miles an hour.
Like any other car you own its good to become familiar with shifting effortlessly into neutral to prevent any kind of engine runaway situation. Its very very easy.
This procedure can be done safely at any speed.

 

Those battery readings are OK, there's no need to replace it immediately. It is a sealed AGM so if you really want to check the water level you'll have to pry it open.

 

it just happend to my father's prius this morning, i dont know f i did stupid thing, but i moved the gear stick to D & hold it there with my hand, & start moving with the car, after 2-3 sec's i left the gear stick without any problems !!!

 

R-P, I experienced the 'cannot shift into D' twice in one day over a year ago but the car has been trouble free since. I excluded the brake sensor and 12V as the problem, so if it recurs I plan to replace the shifter. It costs about $70 USD used + shipping, and is very easy to install DIY.

 

I have been dealing with the same issue for a few months now on my 2008. The Toyota guys have no idea but I see people writing about it all over the Internet. You turn on your car like usual and all the amber lights come on and you can only shift into Neutral and nowhere else. Sometimes you can turn the car off and then back on and it works, and sometimes there's nothing you can do. Sometimes I can't get the car to shut off. They've replaced a battery, and something else and every time I come in the guy says "Sounds like an electrical problem" well DUH - I need to find someone who actually knows this car and that person does not work at the Toyota Dealership (North Hollywood Toyota) where I have my car services. If anyone finds a solution, please tell me. I've spent a bunch of money and these guys don't know what the problem is.

 

Also for all the people blaming user error, they just haven't had this problem yet. It's not user error. The dealer got the car to replicate the problem and they know how to start a Prius and I've been driving this one since 2008 so I have truly figured out how to start my car in that time. It's not user error.

 

My first guess would be that the brake light switch is faulty and needs to be replaced. Press HARD on the brake pedal when you are trying to make the Prius READY.

 

The next time it does not start, have someone check for brake lights, or look for the reflection from them if you are in a position to do so.

 

"The next time it does not start, have someone check for brake lights, or look for the reflection from them if you are in a position to do so."
The Prius brake light switch actually is composed of two switches (one is normally open, the other is normally closed), and both must operate correctly for the car to become READY. The hybrid vehicle ECU expects to receive signals from both switches.

So, if the brake lights turn on, that is evidence that the normally open switch is working but does not prove the other is operational.

 

I can't remember if I read the symptoms of a bad combination meter, would that prevent the car from shifting into drive? Someone pull up the TSB on the symptoms of bad combination meter.....

 

A bad combination meter (which is evidenced by the speedometer not working) might prevent the car from moving from READY to IG-OFF.