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Replaced 12v, P0A80, won’t start.

Discussion in 'Gen 2 Prius Technical Discussion' started by dirt657, Jan 10, 2019.

  1. dirt657

    dirt657 Member

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    Went to go take a look at a Craigslist Prius last night. 2008 in beautiful shape. 180k miles the guy said the car wouldn’t start and I would have to jump it. The car was completely dead. I put some jumper cables on it from my 2010, the lights came on, but the car still wouldn’t start. All lights on on the dash, problem light on on the screen, and a battery symbol that said main. While the car had power from the cables, I checked the code. P0A80. Easy enough, but the car wouldn’t start. As soon as I pulled off my jumper cables, the car died. I put my spare 12v in the car and the lights stayed on, so I determined the 12v was toast in the Craigslist car. But with my perfectly good battery the car still wouldn’t start. I heard the hybrid battery click on, but gas motor wouldn’t turn on. Anyone have any guidance? If never had a car with a bad hybrid battery not start up before. Apparently the car ran 2 weeks prior.

    In a nutshell
    1. 12v was bad, car was completely dead, changed it, car got power. Still won’t fire up.
    2. No codes other than 2 P0A80’s.

    I can buy this car for cheap. It’s a nice car, but it’s a long drive and if I go back with a new hybrid battery I wanna make sure it starts. Send some help my way!
     
  2. bisco

    bisco cookie crumbler

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    the hybrid battery is dead, what are you confused about?

    the 12v does not start the engine
     
  3. dirt657

    dirt657 Member

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    I’ve started tons of cars with P0A80 codes on before. Why won’t this one start?
     
  4. Skibob

    Skibob Senior Member

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    What Bisco was trying to say was that when the traction battery voltage is depleted to a certain point there is not enough power in the traction battery left to start the car. That might be the problem. Do you have a way to see what the traction battery voltage is?
     
  5. dirt657

    dirt657 Member

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    I’d have to strip it all the way down and test it I’m assuming
     
  6. ericbecky

    ericbecky Hybrid Battery Hero

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    I work on hybrids for a living and there are plenty of P0A80 scenarios where the car won't start.
    Shorted cell
    Low voltage/SOC
    Bad cables
    etc

    Get out Techstream to narrow down possibilities.
     
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  7. Skibob

    Skibob Senior Member

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    Techstream or other programs can tell you state of charge from the OBD connector.
     
  8. JC91006

    JC91006 Senior Member

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    Craigslist and cheap?

    Maybe the guy selling the car knows a lot more about it than you do? If I were to sell a car on craigslist and cheap, I would put a pack with 28 junk modules in it and sell it to some guy that thinks he's getting a good deal. It might even have a bad engine and transaxle in it.....but the bad battery will hide it.

    Just for fun, check if the AM2 fuse is blown. Maybe, just maybe this person had a shorted inverter pump and let the car sit to where the battery died too.
     
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  9. TMR-JWAP

    TMR-JWAP Senior Member

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    Geez...remind me to never buy a car from JC, lol.

    Anyway...don't forget that a blown AM2 will kill the dashand MFD/radio so the car would appear to be completely dead except for the car/key icon and the green led at the FOB slot.

    You mentioned you heard the HV relays come on line. Did the car actually go "ready"?

    I would assume the car will be dead again if you go back, so all the codes will be clear. I would remove the dead 12v and connect a fully charged battery. Keep foot off the brake and press power button twice. This way the car never tries to go ready. Now connect techstream to do a health check and check battery module voltages. SOC probably will not be accurate, since the 12v was dead and it probably will be displaying a default value. After you get any desired info from TS, then foot on brake and press power button again to have it try to go ready. See what TS says.

    Have the spare HV battery ready to install.
     
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  10. dirt657

    dirt657 Member

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    Ordered tech stream today. It's a really old Indian couple. Really nice people. Don't thing they are trying to pull a fast one. But today they told me the title was missing. I'm not even gonna mess with it anymore. I've already got 3 at home that I'm waiting for titles for so I can sell them.
     
  11. JC91006

    JC91006 Senior Member

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    Get a 4th for parts
     
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  12. dirt657

    dirt657 Member

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    Thinking about it