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2005 Prius Warning Lights On

Discussion in 'Gen 2 Prius Main Forum' started by Johnswd, Dec 30, 2016.

  1. Johnswd

    Johnswd New Member

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    Dear all,

    My 2005 Prius has about 224,800 miles on it. I has been driving okay until yesterday. While driving, there are many warning lights coming up, including the check engine light, Red Triangle, VSC and "!" lights are all on. I asked autozone to pull out the code to be "P0A80, replacing hybrid battery pack". Does it mean I need to get a new battery? I heard it is very expensive, around $3000. Do I need to spend $150 to let Toyota Dealer to diagnose it again, just to be sure it is the hybrid battery problem?

    In the mean time, after reading some posts from the forum, I did the following diagnoses myself:
    1. I take out the fuel cap, and put it on until it clicks. It did not help
    2. I tried to see whether it is the 12V auxiliary battery problem by checking the vehicle in the maintenance mode. I did it twice under two conditions
    (1). After the car has been sitting/idling for 16 hours, I press the power button once and turned the head light signal 3 times while holding the MFD Info button, then "Menu", "Display Check" and "Vehicle Signal Check". I saw my battery voltage to be 11.9V (less than the range of 12.4-12.8V as someone in the forum said). Then I press power button again and release, the voltage became 11.4V, less than the 12V as suggested. Then I press the brake pedal and press power again, enter into "ready" mode, the voltage shows 14.1V, which is supposed to be normal.
    (2). After driving the car for 30-60min, I followed the above procedure and checked the voltage again. The readings are: 12.5V (unloaded), 12.0V(loaded), and 14.1V (at Ready position).

    I was told by the autozone technician that the first time check was not accurate because the car has been sitting in the cold weather (30-37F) for 16 hours, it is normal that the battery to read 11.9V (unloaded). As he pointed out, the battery voltage returned to normal after driving 30-60min.

    What is the best option to me at this point? I don't want to spend another $3000 for my car because it is already old and has >200,000 mileage on it. Looks like I can do the following two things:
    (1). Get a used battery. How much this will cost including installation?
    (2). Trade in the vehicle and get a new one.

    Not sure if I even needed to spend another $150-200 bucks to let toyota dealer to check it.

    Thanks!
     
  2. bisco

    bisco cookie crumbler

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    welcome!

    how old is the 12v?
    it's tough to guess with this stuff being so expensive, but if it's original hybrid battery, i would not be surprised.
     
  3. JC91006

    JC91006 Senior Member

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    No need for dealer diagnostics, it needs a new hybrid battery
     
  4. Johnswd

    Johnswd New Member

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    Thanks for the quick reply! I never replaced my 12V battery. I bought my vehicle 5 yrs ago as a used car. At that time the mileage was 80,000 miles. Not sure if the previous owner has replaced the battery, most likely not. So probably the battery is 11 yrs old.
     
  5. JC91006

    JC91006 Senior Member

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    You can easily test the 12v battery at any auto parts store. But it's the hybrid battery that will cost you the arm and the leg
     
  6. Johnswd

    Johnswd New Member

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    Thanks, JC91006. I guess you are right. Looks like I have to get a new car because it is not worthwhile to get an expensive battery for my old 200K miles car.
     
    bisco likes this.
  7. bisco

    bisco cookie crumbler

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    some people put a new battery in, then if something else expensive comes up, they look for a pri in need of a battery and swap it in.
     
  8. jadziasman

    jadziasman Prius owner emeritus

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    I sold my 05 Gen 2 three weeks ago for the same reason - the HV pack was weak and had little remaining life but it had not failed like yours.

    If only the replacement options had been cheaper I probably would have kept mine.
     
    #8 jadziasman, Dec 30, 2016
    Last edited: Dec 30, 2016
  9. Johnswd

    Johnswd New Member

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    One more question, guys. What is the worst case scenario if I keep driving my car at current state (i.e. with the check engine and the other warning lights on)? Right now it drives okay, but I don't know whether it will be still be like this in the next two weeks if I keep driving it. I am asking this questions because shopping for another new car takes a little bit of time (say one week or two). During these two weeks, is it safe to drive my old car as is? I guess the worse case scenario is that the battery slowly degrade and my MPG will be lower, but overall I can still drive it at least for a couple of weeks, right? I have a long commute to work each day (about 55miles one way), so everyday I put about 110 miles on it, which is the reason why I got Prius in the first place! Thanks.
     
  10. bisco

    bisco cookie crumbler

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    it's possible but unlikely that the battery will die and you will be stranded. but impossible to predict.
     
  11. jadziasman

    jadziasman Prius owner emeritus

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    Bisco nailed it.

    If you continue to drive it as is, it's highly doubtful that it will be fully functional for two more weeks. The battery management system will not be able to charge the pack correctly with the failed module. Your Prius will probably go into limp mode in the next few drive cycles and strand you, potentially far from home. .
     
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hence, as a workaround, one possibility would be to carry a 10 mm wrench so that the 12V battery negative cable can be disconnected where it bolts to the body. The point of doing that is to clear the logged DTC so that after the cable is reconnected, the car will start.

    However this workaround should not be used more than once or twice, because as the traction battery continues to deteriorate the failing module will overheat and may start a fire within the traction battery enclosure. Hence, consider this to be a 'get out of jail" card that can be played only a limited number of times.
     
  13. Johnswd

    Johnswd New Member

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    Thanks very much for all your help! I just traded in my car in a dealership for $500 today, and bought another used car (Prius C, year 2013 with about 20K mileage), so this one will give me at least 4-5 years of traction battery warranty. BTW, I live in Pennsylvania. Is Pennsylvania one of the California emission states that grants you 10yr/150,000 miles batter warranty? I googled some websites, it is confusing. Some website does say PA has the same CA emission, but the warranty information from my dealership shows it only carries 8yrs/100,000 miles batter warranty.
     
  14. wjtracy

    wjtracy Senior Member

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    Hi John- PA is standard CARB whereas extended CARB (MD, NJ, NY, CA etc) gets the better warranty. So you just get the standard warranty 8yr 100000miles. welcome aboard and hope you like the "c".
     
  15. Johnswd

    Johnswd New Member

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    Thanks, wjtracy, good to know that PA only carries the standard warranty. I will keep it in mind!