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How long would ECU reset last on a bad battery?

Discussion in 'Gen 2 Prius Technical Discussion' started by MountainDriver, Mar 8, 2019.

  1. MountainDriver

    MountainDriver New Member

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    Location:
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    Vehicle:
    2005 Prius
    Model:
    Two
    So, a couple of days ago I bought a 2005 Prius. But I was a very foolish when I bought it (I'm often very trusting and naiive): I didn't take it to a mechanic, and the seller didn't provide a smog certificate.

    After owning the car for two days and driving home around 400 miles almost entirely on the highway, the check engine light, red triangle excalamation, and orange 'Check hybrid systen' all came on. I took the car down to the local O'Reilly's to get the codes read, and they came up with P3000 (Battery Control System Malfunction) and P0A80 (Replace hybrid battery pack).

    I am wondering whether the seller of the car may have reset the ECU so that it didn't have any check engine light on, or whether I am just unlucky to have bought the car right before the battery pack started to fail. Is it possible that the car could take that long before re-detecting the failing battery pack?

    I intend to take it to a smog place as soon as I can to get more complete ECU information (I understand that after a reset, some parts of the ECU will indicate 'Not Ready' until the car has been driven a decent ways), and have the car booked in at the Toyota mechanic for a complete inspection / to get more detail on the error codes on Tuesday.

    Any advice would be greatly appreciated.

    P.S. as indicated, I am aware of my stupidity in buying a car without a smog certificate / mechanic inspection. Hopefully I will remember this next time I need a new car.
     
  2. bisco

    bisco cookie crumbler

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    welcome!
    disconnect the 12v for an hour, and see how long it takes to come back on. don't trust oreilley reader, take it to a dealer or get a copy of tech stream.
    all the best!(y)
     
  3. SFO

    SFO Senior Member

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    No need to remember, as they've shifted stupidity onto the seller :whistle:

    Seller fail to Smog? BIG MISTAKE. — California Lemon Law Attorneys

    You can check for maintenance and recalls by running the VIN at : http://www.toyota.com/owners

    Never know, you might even find out that someone played with the Odometer before the sale :cautious:
     
    Skibob likes this.
  4. MountainDriver

    MountainDriver New Member

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    2005 Prius
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    Oh, that smog link is interesting, and good to know. Thanks also for the toyota owners link, I'll check it out too
     
  5. Skibob

    Skibob Senior Member

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    Yes it’s on the seller in California to smog the car. You should get your money back and walk away, unless the car was so cheap that your ok with replacing the battery (over 2000). My money is that they knew there was a problem and was hoping to dump the car.
     
    #5 Skibob, Mar 12, 2019
    Last edited: Mar 12, 2019
  6. MountainDriver

    MountainDriver New Member

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    Location:
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    2005 Prius
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    Perhaps the issue is something else.

    I drove it down to fail a smog yesterday. Explained to the guys doing the smog that the light was on, I just wanted documentary proof that it couldn't pass smog. Ten minutes later the mechanic comes back to me: "There's nothing wrong with your car, that's just the oil change light (The maint required)." "Nah that can't be right, the check engine and exclamation was on while I drove down here..." so I hop in, press the power button... and everything is fine. Ok. So I got it smogged.

    Today, driving, the dashboard lights up again with the Triangle excalamation mark, check engine, and also the brake control system ((!)) warning light. But it's still driving alright, and I've got an appointment in the next town over, so on I go. No problems, but next time I start the car the dashboard won't turn on and the energy/consumption screens don't work properly - but it still drives fine. Then it won't turn off - but again, still drives fine. Finally I get back home, and it turns off fine, then turns back on and the dash and everything is working (although it hasn't recorded the last 40 miles while the dash was off) but the check engine and red triangle are still on.

    I understand that the best idea might be to try reverse the sale. I can also imagine that might need me to go to small claims court - so if it turns out to be a fixable problem, I would prefer to do that.

    Perhaps it's the 12V system? I don't know. I cancelled the appointment at the dealership when the problem spontaneously resolved, but now I've got another one on Thursday. Hopefully there's actually a problem for them to diagnose when I bring it in.
     
  7. SFO

    SFO Senior Member

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    The first issue sounds like your combo meter (instrument panel) is failing, order and install one from @Texas Hybrid Batteries or Prius Speedometer Replacement and if you can't do the install yourself, you could take a chance with a CL offering instead.

    Sounds like you may have DTCs (codes) stored that could be retrieved with an OBD2 hybrid compatible scanner, if possible take it to one of the various auto parts chains and borrow their scanner. If their scanner doesn't retrieve any stored codes, try another chain or even another store within the same chain, as every store offers different scanners for loan. Without the codes it would be hard to say what the problem might be, and the dealer will require the same codes at your expense (either way).
     
    #7 SFO, Mar 12, 2019
    Last edited: Mar 12, 2019
    Raytheeagle likes this.