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Hybrid System Warning light, Triangle of Death light on, still drives fine

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ironcross90, Mar 9, 2015.

  1. ironcross90

    ironcross90 Junior Member

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    A few days ago I was driving my 2005 Prius aggressively up a mountain road and all at once the hybrid system warning light, the triangle with the exclamation point, and the regenerative brake system warning lights came on.

    After about 2 minutes parked, I restarted the car and the regenerative brake system warning light went off, but the other two were still on. I still drove it twenty miles home, over another substantial mountain gap (about 1000 ft up and another 1500 down), without any problems.

    I checked the voltage of the 12v battery, which seemed to be on the low end, but OK. (I think the lowest reading was 11.9). There seemed also to be some turbulence in the inverter coolant reservoir.

    I brought it into the electronic vehicle specialist in town here today, who pulled my codes and said that the hybrid battery was dead.

    I am wondering how that would happen so abruptly and still allow me to drive relatively aggressively up and down a mountain before I brought the car in.

    Thanks for thoughts!
     
  2. nh7o

    nh7o Off grid since 1980

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    What was the State of Charge display showing when this was going on?
    Did you hear the battery fan running at high speed in the back seat?
    Was the engine revving quite high?
    How many miles on it?
    Please list all the DTC that were read by the scanner.

    The error condition can be transient, and if the battery cools enough the car will be drivable for a while. But it will return again whenever the battery overheats, if there is a bad module acting up. If the battery SOC goes very low, the engine will rev higher to make up for it.
     
  3. ironcross90

    ironcross90 Junior Member

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    Thanks for the response!

    When the light initially came on, the charge had reached the bottom bar (this happens to me often, I am generally working the car quite hard as I go up the mountain. The bar always returns to almost full by the time I have come down the other side of the mountain, including on the day when the error showed.)

    The battery fan was not running at a higher speed than normal

    The engine was revving high when the light initially came on, but it always does during that section of the drive.

    The car never stopped driving normally, and is still driving normally, but the error lights remain. but I have not yet subjected it to the punishing uphill climb again.

    It has about 175k on it.

    I will have to check with the shop for the specific codes that the Toyota scanner read.
     
  4. nh7o

    nh7o Off grid since 1980

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    No one will be surprised that a 2005 with 175K in mountainous terrain is in need of battery work. Are you the original owner? It has been a good long run. You might start to consider some of the options that are well covered in threads here.
     
  5. ironcross90

    ironcross90 Junior Member

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    Yea, that is what I was afraid of! I guess I had just projected those 200k+ onto my car, when clearly my commute is not the same.

    Not the original owner, but know him pretty well. He dealt with similar terrain, as it is hard to avoid up here.

    Thanks for the help.

    Ben
     
  6. nh7o

    nh7o Off grid since 1980

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    If the battery performance has dropped over time, perhaps the original owner didn't really make any detailed assessment of the situation. I would guess that what you have seen as "normal" is substantially reduced capacity from the beginning.