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Hv battery blower motor not turning on

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Jav_bug, Feb 25, 2021.

  1. Jav_bug

    Jav_bug New Member

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    Hi there. I have a 2012 gen 3. My issue is the hv battery blower fan not turning on. I see a resistor (I haven't touched it yet) but is/are there relays or fuses I can check in the mean time? I found a 10A fuse in ngine compartment fuse box that was good. I also found three relays marked fans, 2, and 3. I switched them around and still no change. Is there any fuse or relay I can check and where? Thanks for your time and attention.
     
  2. ASRDogman

    ASRDogman Senior Member

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    How do you know that fan is not working? Have you taken it apart and cleaned it?
    And tested it? Are you getting a code saying the battery is over heating?
     
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  3. PriusCamper

    PriusCamper Senior Member

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    Can you please give us more details? Generally the fan is rarely in operation...

    Do you an have an error code for voltage problems with cooling fan? Or are you just trying to confirm it works?

    Hybrid assistant app is a good way to confirm your fan works, but you'll need an obd2 reader.

    Here's buyer's guide: Hybrid battery diagnostic and repair tool for Toyota and Lexus
     
  4. bisco

    bisco cookie crumbler

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    you can turn it on manually with a scan gauge
     
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  5. Jav_bug

    Jav_bug New Member

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    Thank you for the response. I have been getting the framed window to find a safe parking location and stop the vehicle. This is my third or forth time. A quick YouTube search helped me clear the dash warning and be on my way. 2000 miles and the same happened. I cleared the lights again by disconnecting all connections to batteries and waiting . Third and forth time the same occurred 400 miles apart. Initial scanner look up came back p0A80 as did all other scans. Opening the trunk hv battery access to the blower motor and inspected air passages for obstructions including RR door jam vent. No obstruction. And no air moving either. Multiple attempts at initial start up and no fan movement even after 20 to 30 minutes of on while accelerating to charge the hv battery, as YouTubers showed would happen on startup. I probed with vom and light probe for power. Power was present on green wire while yellow, white and black showed ground. While I was preparing to remove the blower it suddenly started and shut off after approx. 1 minute. Then again no more startup. While probing with the light probe the fan hit full on as I tested yellow wire with ground. So the fan does work. But may be failing at a fuse, relay or controller module was my thinking. As for expensive scanners with advanced cycling features, I do not own. So my question is a logical one following the control path. I will give the link a go and see where that takes me. I'm a 35 year shade tree diy mechanic having saved myself and family well into tens of thousands in repairs by shop rate standards. This is my first forum experience. So please forgive my Newby vibe. Any productive information is appreciated in advance.
     
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  6. Jav_bug

    Jav_bug New Member

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    Oh, I forgot to mention that after the first episode, I took my prius to a local prius aficionado. He scanned it with a fancy tablet sized touch screen scanner (I gotta get me one of those!) And came up with the historical DTC codes which were not the same nor relevant to the current problem. He then spent the next 2 hours disassembling the HV battery and testing each and every individual cell. The verdict, all cells are in top condition and within specs for voltage and current load values. The HV Battery is great. So this is where I am thinking cooling may be an issue.
     
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  7. PriusCamper

    PriusCamper Senior Member

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    There's a specific subcode to P0A80 that indicates there is a problem with the fan... An OBD2 bluetooth adapter for less than $30 is good to keep in your glove box, as it allows you read primary and battery subcodes via Dr. Prius app. But the battery fan doesn't sound like your problem as you were able to get it to run.
     
  8. Grit

    Grit Senior Member

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    That was needed from an hv fan issue? 2 additional hours billed for labor, the cleaners.
     
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  9. PriusCamper

    PriusCamper Senior Member

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    yep... If you don't have the gear you need to read the subcodes you can charge lots of money testing the hybrid system...
     
  10. Jav_bug

    Jav_bug New Member

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    Ok. I'll look into this. And this is a curious problem. And an evasive one as well. After cleaning all the copper contacts and the individual cell testing for V and Load balancing, the car later blew the same code and warning. That advice should help me get to the nitty gritty.

    True. Knowledge is power. Even if it comes in informal setting.

    Not per say, but was already in my train of thought as corrosion is a big player in any electrical or electronic system. The big price? Well I just didn't have time to do it myself that particular moment. That's life.
     
    #10 Jav_bug, Mar 6, 2021
    Last edited by a moderator: Mar 6, 2021
  11. PriusCamper

    PriusCamper Senior Member

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    Doesn't seem like you've got the subcodes to this problem yet... Let us know when you do... You're flying blind without those subcodes...
     
  12. Jav_bug

    Jav_bug New Member

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    Thanks. I'll keep you all informed when I do. Been pretty busy with lots of happenings.
     
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  13. John Karp

    John Karp New Member

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    Hello!
    So what happened with your story, you didn't come with any updates!
    Did you fix the problem?
    I am facing the same situation with my 2023 Prius c, code P0A80. Cooling hybrid battery fan not working at all, measured hybrid batteries and they appear to be in the optimum range.
    Please any inputs would be greatly appreciated.
    Thank you!
     
  14. John Karp

    John Karp New Member

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    Please come with a update!
    I am having the same situation like yours!
    Thank you!
     
  15. Grit

    Grit Senior Member

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    you got a car that hasn’t been released let alone designed yet and it’s having a hv bat issue, mind blown away.
     
  16. ChapmanF

    ChapmanF Senior Member

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    To the best of my knowledge, that's not the case; P0A80 is a code that's specific to voltage differences between blocks of the battery, and there are separate codes P0A82 and P0A84 that refer to the cooling fan. I am looking in a 2010 Gen 3 manual, so maybe someone can show a new fan-related subcode that was added for P0A80 in some later year. Nonetheless, I think it would be pretty odd to add a fan-related subcode to the inter-block voltage DTC, rather than to one of the fan-related DTCs already defined.

    That would mean in a car that's giving a P0A80, it makes sense to focus on the inter-block voltages; focusing on the fan in that situation would be a bit of a distraction.

    I also noticed a post from the OP where somebody with a fancier scan tool "came up with the historical DTC codes which were not the same nor relevant to the current problem". That was back in February, so I won't say this so much for the OP, just for anyone who may post questions in the future: if a bunch of codes have been retrieved that you've judged not to be relevant, it still never hurts to say what they are in the PriusChat thread, and mention that you doubt they are relevant. In some cases they may still help to complete a picture.
     
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