They are dozens of threads on the dreaded P Lock problem. Few of them lead to a solution. This thread title is intended to stand out and lead others to a simple repair.. It seems there is more than one possible cause. My 2008 Prius had an intermittent P Lock problem. This You Tube video shows the source of the problem with my car. Here's a shot of the freeze frame data from the C2310 code. The eighth line of the left column labeled "Battery Voltage Value" showed .62 volts. That voltage is what the Transmission Control Computer is reading at pin 13. The computer needs a constant 12 volt supply to retain the memory of the P Lock mechanism position. The You Tube video shows the fault can lye between the 7.5 amp "P Con" fuse and this plug next to the positive jump point in the engine bay fuse box. It's the blue wire that leads from the P Con fuse to pin 13 on the Transmission Control Computer. On my car the pin for the blue wire had corroded to the point of breaking. I installed a jumper wire from the P Con fuse to the blue wire which restored a good 12 volt supply to the Transmission Control Computer.