Getting a "Check Hybrid System" after cleaning the cooling fan

Discussion in 'Gen 3 Prius Technical Discussion' started by Priusbill1, Jul 17, 2025.

  1. Priusbill1

    Priusbill1 Junior Member

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    I watched a couple of You Tube videos about cleaning the fan on a Gen 3 Prius, 2012, 212,000 miles and had never been cleaned. Everything went as expected and when I finished the job, the car wouldn't start and had a Check Hybrid System warning light on the dash. I removed the orange safety disconnect before I started and reinstalled it. After getting the message, I removed it and reinstalled it again to make sure I had it installed correctly, but got the same message. Other than the cooling fan, I didn't touch anything else on the hybrid battery. What could be wrong? What can I check? I can't even drive the car at this point, it won't allow me to put the car in gear.
     
    #1 Priusbill1, Jul 17, 2025
  2. xliderider

    xliderider Senior Member

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    Did you properly connect the orange safety connector? You have to push it down until it clicks after rotating the lever up 90 degrees, many forget the second step.

    If you do that correctly and still get the Check Hybrid error, disconnect the negative ground cable from the battery to the body, wait 5 minutes, then reconnect. Then try to power the car on again.

    SM-S936U ?
    View attachment 275987
     
    #2 xliderider, Jul 17, 2025
    Last edited: Jul 17, 2025
  3. ASRDogman

    ASRDogman Senior Member

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    Remove and install the orange safety plug, do it slowly, each step. Make sure you are pushing it to
    the right ALL the way, and pushing the lever ALL the way is. It's easy to not do it correctly.
    It "should" be easier to reconnect, butttttt....

    And clear the code with the Prius app or any other tool. Remove the negative cable on the 12v battery
    for 30-60 minutes might also clear all the code, but not 100% certain on that.
     
    #3 ASRDogman, Jul 18, 2025
  4. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Ive cleaned ours a couple of times now, didn’t remove the safety plug and AFAIK it’s not necessary. I’d concur, the safety plug seems the most likely cause. Anything else electrical disconnected?
     
    #4 Mendel Leisk, Jul 18, 2025
  5. Priusbill1

    Priusbill1 Junior Member

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    Thanks for all the responses. I watched another You Tube video and found that I had not moved the safety disconnect to the right, so I did that step, but still had the same problem. That same video said to remove the safety plug and unplug the large white cable inside the fuse block under the hood and wait 10 minutes, then reconnect. That solved the problem.
     
    #5 Priusbill1, Jul 18, 2025
    ASRDogman, Mendel Leisk, xliderider and 1 other person like this.
  6. xliderider

    xliderider Senior Member

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    Whew, glad that worked out for you. I've been putting off cleaning our 2010's battery cooling fan.

    Must have been pretty stressful when you ended up having problems afterwards.

    SM-S936U ?
     
    #6 xliderider, Jul 18, 2025
  7. ASRDogman

    ASRDogman Senior Member

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    It's very common, happens to the best of us..... I'm glad it resolved your issue...
     
    #7 ASRDogman, Jul 18, 2025
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