Hey guys, First off, thank you for any help and insight. I love how active this community is and how great some of the members are in contributing excellent information. I know this is a common error code to get. I'm pretty sure the HV battery has some bad cells. I bought the car, a 2008 prius with 125k miles for 1k$. The last owner had been working on it, had it running but let it sit for 8months due to family issues and other projects. He said he tried replacing a few of the packs inside with some he had bought on eBay. Didn't work and he gave up and sold it to me. So I get the P3000 P0afa code when I use my Bluetooth scanner and Dr. Prius app. No surprise there that the battery still has issues. I have reluctantly ordered a reman cardone from rockauto. Depending on the return process I may return it before I even open it up. I saw newpriusbatteries and it has me very interested. My questions: The Dr. Prius app shows voltages all over the place (see picture) sometimes negative even. Is this possibly a sign of a bad ECU? I have not taken out the HV battery to inspect wiring harness etc. For corrosion yet. I'm asking this because I really can't afford to get the newpriusbatteries set and pay for a new to me ecu. I'm thinking I may test the cardone battery to see if it revives the car and return it if it doesn't show good results in the Dr. Prius app...but only if I can return it if it's opened. How can I test the ECU though? I'm also thinking of getting a hobby charger (and light bulb) and recharging/discharging the packs to see if I can pull off a low budget miracle. Also....how many people have had success with newpriusbatteries product??? I read the whole 23pg thread and only saw one guy who documented his experience. I have been self studying IT certs for an enterprise job and working as a house manager at a small transitional housing organization for the homeless. I've never been homeless. It gave me free rent (and is a great cause) While I studied. So I have verrrrry little budget wiggle room. Thanks Again for listening and any advice.
Welcome! If you can find or borrow an old compatible windows laptop, a copy of tech stream software for $25. Might be helpful to you
My bet is that the connections aren’t tight and you’re not getting everything working together well. In addition to what @bisco said above, I’d pull the orange safety plug and open up the pack and see what you are dealing with. Good luck and keep us posted .
Negative voltage readings are usually indicative of : a damaged wire or connector tab on the voltage sensor harness corrosion at the sensor harness plug terminals corrosion at the ecu plug where the voltage sensor wire harness plugs into Unfortunately, after 8 months of sitting, you may also have some modules that have self discharged. If you're able to check each modules voltage, it would at least give you a basic idea of where you're sitting in that regard. This would also give you opportunity to inspect the items mentioned above.
Since you need to remove the pack and orange interconnect covers, you might as well just perform a capacity test on each module after confirming the nuts are properly torqued.
I saw another post after I posted this: P0A1F code, weird voltage readings | PriusChat It was a very similar issue. I hope the ECU hasn't had All it's magic smoke let out.
This is the classic battery ECU/sensing harness issue. You need to address this ASAP before it gets worse and results in a burned out ECU, sensing cable and fully discharged modules on block 1,2 and maybe 3.
