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“Check Hybrid System” after cleaning HV battery fan… where do I start?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by goshdonit, Aug 12, 2022.

  1. goshdonit

    goshdonit New Member

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    Cleaned the HV battery fan in my 2010 Prius yesterday. I followed this instructional video at first, but I switched partway through to this one from NutzAboutBoltz, which seemed like a more efficient process that required less trim removal.

    In retrospect, switching videos just added confusion during the reassembly process, and two problems have come up as a result:

    1. As a newbie amateur, I didn’t develop the best system for organizing screws, bolts, etc. beforehand, and I had a couple small mixups with replacing things. I think I eventually got everything back together alright, but I’ve got this extra Philips hex head screw and washer (see picture) and I cannot for the life of me determine where it came from. Anyone have any ideas?

    2. A much bigger problem is that I tried powering on the car after reinstalling everything and got the “check hybrid system” warning on the dash. Tried switching the car to Drive and heard the ignition switch click, but no engine start. Without the engine running, I cannot run my BlueDriver OBD either it seems (not entirely sure if that would even be helpful here tbh). Upon inspection, I realized I hadn’t fully inserted the HV battery safety service plug, so I removed it fully and then reinserted it fully. Still didn’t get the car to start.

    I can’t afford to **** this car up, so I’m just checking: how should I proceed? Should I check fuses first, or remove the trim again around the HV battery fan and check that everything is in order? Does the car just need a jump, or is my hybrid battery now a goner? Lol I’ve searched the forums but have seen many answers and am not sure how to prioritize the potential solutions I should try.
     
    #1 goshdonit, Aug 12, 2022
    Last edited: Aug 12, 2022
  2. ASRDogman

    ASRDogman Senior Member

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    What is the voltage on the 12v battery? It shouldn't have died because you had the car off.
    And the dome lights wouldn't be enough to drain it, unless it was weak already.
    Double and triple check that you didn't reconnect something, maybe a connector is not
    plugged in all the way?
     
  3. goshdonit

    goshdonit New Member

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    It’s my understanding that it’s the hybrid battery, not the 12 volt, that starts the ignition, no? Not entirely sure what the relevance of the 12-volt battery is here; my lights all work just fine right now as do all the other 12v-powered accessories.

     
  4. ChapmanF

    ChapmanF Senior Member

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    You only need to get to IG ON to read the trouble codes, No need to reach READY, no need for the engine to start.

    You should go ahead and get the trouble codes, as you asked where to start, and ... that's where. :)
     
  5. bisco

    bisco cookie crumbler

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    it is often the cooling fan plug, loose or corroded
     
  6. ASRDogman

    ASRDogman Senior Member

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    The 12v battery starts up the computers and tells the car all is good, then it will
    trip the relay to activate the hybrid battery. If the 12v battery is low, the computers
    don't get acurate reading and you'll get errors and the hybrid battery won't be activated.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Did you remove/replace the orange safety switch?
     
  8. bisco

    bisco cookie crumbler

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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Ok, just noticed this. :oops:

    That safety service plug might still be a factor? You tried a start up with it not replaced properly, and it's still ticked??
     
    bisco likes this.
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    Just in case:

    upload_2022-8-13_11-39-59.png
     
  11. PriusII&C

    PriusII&C Active Member

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    I would disconnect the 12V battery for a minute, then connect the battery, and try to start the car.