I noticed something today on my 2006 Prius that I wasn't aware of. If the 7.5amp STOP light (aka brake light) fuse under the drivers dash blows or is removed, the car is essentially crippled since you cannot get it into READY mode. Not a very good design in my opinion. So....if your car won't start normally, check that you have brake lights first. If brake lights work, something else is wrong. If brake lights don't work, check the STOP fuse. (brake lights will normally work even if car is off)
It is doubtful the fuse is just for the brakelights, but even so fuses do not blow willy-nilly. Anyways, seems nice that it wont let you go if you can't signal you are stopping to other drivers. One of my cars ties critical car features through the instrument panel. For instance, the alternator enable line (so it actually charges the battery) ties through the incandescent battery illumination bulb. So if the bulb dies, your alternator does too.
Ah yes, brings back memories of my remote starter install. Somehow the stop light wires got grounded out and blew the fuse. Had to borrow another fuse from somewhere else to get to the store to replace it.
Could also be a coincidence too, one day I went to start the car, I depressed the brake and pushed the power button and the "ready" light did not illuminate. I turned it off and on again to reset it, no damage done...but hey my answer is a very long shot.
I believe that this is the case with many cars with automatic transmissions - they will use the break light circuit as a way to sense if the driver has their foot on the brake - if the circuit is not closed many cars will not allow you to shift out of park.
