My daughter is stranded in my 2006 Prius with 35000 miles. The screen showed the message: "There's a problem with the transmission 'P' lock mechanism. Park you car on a flat surface, and fully apply the parking brake." It is parked on a flat surface. What to do?
I'm no expert, but there is at least one thread here on this. The "There's a problem with the transmission 'P' lock mechanism" message has been associated with a weak 12V battery: http://priuschat.com/forums/gen-ii-...ion-transmission-lock-mechanism-abnormal.html You may find more using transmission lock as the search term. With luck, one of the trouble shooting gurus will post up. Oftentimes on Sunday they come up in the mid-late evening. Hope this helps.
It's likely that the car needs a new 12V auxiliary battery which can be purchased from your local Toyota dealer's parts dept. In the meantime, if your daughter can get help on a Sunday evening, see if a jump will help start the car (she must make sure that battery polarity is not reversed as this will likely cause the inverter to fail, a 4-digit repair bill.) Or try charging the battery, however use no more than 4A current flow.