P Lock Malfunction

You mean you swapped the 12v? What brand of batteries did you buy?

Main problem with taking it to a Toyota Stealership is that car is a decade old and they don't do repairs to keep costs down, they do repairs to maximize costs because that's how warranty car repair biz works. So be prepared for them to come up with an estimate that's equal to the value of the car and then they'll try to sell you a new one with your car as a fake discount on price as trade in.

Main thing you want to get from them is to give you the primary error codes and the subcodes and we can help you with repair options and hopefully a Prius expert in Denver area will be able to help you with an inexpensive fix.

In the meantime make it as clear as possible with stealership that you're paying for error code diagnosis and no exploratory investigations. They're too often eager to turn $100 diagnostic jobs into $500 exploration jobs that won't fix anythign, just take more money from you for doing works that the error codes have already done.

 

Oh good... Always enjoyable to a help experienced mechanics with hybrid repairs... A key tool you may already have or want to get is an OBD2 bluetooth reader. Having one in the glove box allows you to use phone apps, especially Dr. Prius app, which will read error codes and most importantly the hybrid system subcodes. Here's buyer's guide: Hybrid battery diagnostic and repair tool for Toyota and Lexus

You can also buy a similar cable that will run Toyota Techstream on a windows laptop, but that's a little more challenging of an install.

 

I usually just start googling for answers. Here's a Youtube video on a quick fix for it:

And below is a screenshot / pic of title of threads to read when you type in "P Lock Malfunction prius" in Google because google knows I like Priuschat.

 

It could be as simple as a bad ground connection from the battery negative post to the frame under the hatch lip near the right rear corner. Inspect for corrosion/arcing and loosen, spin, and tighten for good luck. See what the dealer says on Monday after they inspect and take a load test. They should provide you with a state of charge figure and recommendations. Maybe new battery is defective. Maybe charging circuit is to blame. +1 on recommendations for your own set of diagnostic tools, one time purchase price near what a dealer will charge for their diagnostic. Good luck.