Aloha! Just picked up a free Prius and am trying to diagnose what the issues are. Dr.Prius App pulled the p3000 code and the Red Triangle is coming on so looks like battery isn't charging. App shows #5 block jumping really high and low. Not sure how to interpret this. Car only has 111k. Ran the battery test but not sure if the results are perfect because engine kept coming on when the test was almost complete. Any help would be radical. Mahalos!
You need a hybrid compatible OBD2 reader that can also pull subcodes (INFs), the DTC that you've reported (P3000) has five (5) different subcodes, not knowing the associated INF(s) makes it difficult to offer an efficient course of action.
Hawaii + 2009 Prius = Bad Battery Pack That Dr. Prius app is pretty lame, they report things that they can't. But it is a good barometer, just take the results with a grain of salt. You clearly have an extremely weak module that is fluctuating wildly. You don't have the subcodes for the code you're reading but that code comes from an ECU near the front of the car that says "hey, something is seriously screwy with the HV Battery, you should interrogate the Battery ECU". My guess is the battery ECU has faults logged that show you need to replace the pack and you can see the block you need to replace. If it is a free car and you have all the time in the world to keep playing whack a mole, you can be red-light-free (extremely temporarily) for about $30 on eBay. If you are going to keep this car for some length of time, new is the way to go.