2007 Prius power button not responding

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SarcasticFringehead, Feb 22, 2026 at 5:54 AM.

  1. SarcasticFringehead

    SarcasticFringehead Junior Member

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    Hello all,

    I’m in real trouble now.

    I last drove my 2007 Prius earlier in the week.

    Today I got in and when I pressed the power button, nothing happened.

    No warning lights on the dashboard because the dashboard didn’t start.

    No display.

    The doors did open, I didn’t test the lights but will go outside and do so after I hit send on this.

    Relevant recent repairs: several cells of the hybrid battery were recently repaired/replaced. I had overcharged the battery by following advice to start the car for five minutes every few days. I did so without driving it, because I was giving 24/7 care to a relative and couldn’t leave them alone.

    After the hybrid battery was repaired I would drive it at least once a week for up to half an hour, which was the maximum time I had a sitter available for my sick relative.

    I know that not driving the car is bad and wrong and I deserve for this to happen to me, however, I now need to find a solution. My relative has just now died and I was counting on using this car to have enough employment prospects to keep body and soul together.

    Another possibly relevant condition is that there was a body leak a couple years ago which I had repaired. However there has been continuous rain here and I find that the interior of the car is damp. There is a dehumidifier bag which indicates there is a lot of moisture, and when I picked up the handbook it was clearly affected by the damp. There was a damp patch in the centre of the display last time the car had a functioning display.
     
  2. SarcasticFringehead

    SarcasticFringehead Junior Member

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    Update: the lights are working.
     
  3. SarcasticFringehead

    SarcasticFringehead Junior Member

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    I realize I’m not one of the most helpable posters here, because I’m barely willing to engage in any maintenance myself (I break things), and am really only looking to quell my panic while I wait to take it to a garage.

    Having said that, I am going to place my bets that it will turn out to be the AM2 fuse.

    A look at the pinned threads makes me speculate it’s water in the spark plug wells, because it’s been raining AF here for weeks. Also, the last time my car had noticeable water damage, it was parked in the exact same space it is now (and there’s no obvious reason why that *should* make a difference, but maybe it does).
     
  4. SarcasticFringehead

    SarcasticFringehead Junior Member

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    The hybrid specialist told me it could only be a dead 12v battery and that the garage that replaced it should fix it under warranty.

    That garage didn’t have appointments till today. This morning I got a recovery service to jump start it. But they couldn’t. No visible wiring problems under the hood. They tested the 12v battery directly in the trunk and said it was good to go.

    This is making me miserable. I poured four figures of repairs into this car last year and followed every instruction in every detail, going to great lengths to make sure the car would always be in working order.

    I got away with driving it 12 or 13 times since the last repair before I’m back to the regular scenario that I go to get in it and it won’t start.

    My current job doesn’t pay enough for me to be able to reliably buy food. I was counting on that car to get me to another job that would fill the gap but which would require me to drive to and from the site each time.

    I don’t understand why it has to be this difficult.
     
  5. bisco

    bisco cookie crumbler

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    Unfortunately, it is difficult to troubleshoot without scanning for codes which lead to potential problems.
    If you’re not getting the ready light, make sure the fob light flashes when pressing a button.
    I would test the voltage at the front jump point, then turn on all the lights to see what the voltage drops to.
     
  6. SarcasticFringehead

    SarcasticFringehead Junior Member

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    Right. I need to get to a point of affording an adaptor so I can use the Mr Prius app. :(

    The good news is there are no codes to read, because there’s no power. A different recovery service had to come with a crane to move the car, because there’s no way to get it out of neutral.

    I also need to afford a volt meter.
     
    bisco likes this.
  7. dolj

    dolj Senior Member

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    Mr Prius is not a good app for comprehensive app for Prius diagnostics, it is more focused on the hybrid vehicle (HV) battery. You need to look at, and budget for, the Autel AP200 (not the AP2500). It is a reasonable price for lifetime (free) license for one car make. Amazon seems to be the common source.
     
    Brian1954 likes this.
  8. ChapmanF

    ChapmanF Senior Member

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    I've heard of Dr. Prius. Could there be a different Mr. Prius app?
     
  9. mr_guy_mann

    mr_guy_mann Senior Member

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    Initial guess based on your symptoms - check the AM2 fuse in the underhood fusebox. If it's blown then the inverter water pump has likely failed (shorted).

    That fuse supplies ignition power to several other systems on the car. No AM2 = no turning on.
    Posted via the PriusChat mobile app.
     
    #9 mr_guy_mann, Feb 27, 2026 at 9:00 AM
    Last edited: Feb 27, 2026 at 1:04 PM
  10. Hayslayer

    Hayslayer Active Member

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    If you think it's the AM2 (and your symptoms are similar), there's a small one wire connector just above the underhood fusebox. Unplugging that connector will remove the inverter cooling pump from the circuit. Then replace the AM2 fuse. See if the car powers up. The car can be driven quite a bit without that pump running as long as you stick to non-highway speeds.
     
  11. mr_guy_mann

    mr_guy_mann Senior Member

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    Here's the AM2 fuse, and the connector that will disable the inverter water pump as mentioned. gen2%20fusebox.jpeg

    Posted via the PriusChat mobile app.