Voltage Leak to Ground Fix

Discussion in 'Generation 1 Prius Discussion' started by Chris Saunders, Sep 19, 2020.

  1. Chris Saunders

    Chris Saunders New Member

    Sep 19, 2020
    Virginia beach, VA
    2003 Prius
    I've gotten a lot out of forums and am writing to give back. I hope this helps someone. I have not seen this fix anywhere else. I am writing this a few months after the repair and if I leave out some details it's because I let too much time go by.
    In short, my Prius got the red triandle of death. An OBD2 reader showed no errors. I got a hold of techstream and it showed there was a voltage leak to ground (P3009 and P3000). After a bunch of troubleshooting the fix I found was... cleaning the cells. This is what I mean. I removed the battery, the bus bars, and the bolts holding it to the case bottom. I found that there was continuity from the terminal studs to the mounting stud on the bottom. I cleaned a cell with acetone and the reading went to OL (meaing no path.) I cleaned every cell until I received the same reading from each terminal to each mounting stud I put the whole thing back together doubl-checking the readings the whole time. After reinstalling, the error did not return. The vehicle has been functioning correctly for several months. This Prius went from probable end of life to back to full daily driving for about $10. There are a bunch of bolts to remove but it is not a difficult procedure. It is time consuming but well worth it.

    My belief is that the fan has been blowing unfiltered atmospheric air over the battery for 17 years and coated it in aerosolized hydrocarbons until they built up to a point of conductivity. Cleaing the battery removed them.

    I hope this saves a Prius or two and an owner a bit of coin.