Dashboard/Instrument cluster not lighting up with new battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by tinkertwain, Jan 4, 2025 at 2:59 PM.

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  1. tinkertwain

    tinkertwain New Member

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    2008 Prius
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    Three Touring
    We returned after 10 days to find the battery of our 2008 Prius dead. I jump-started the car, but it died again the next day. I jump-started it again and let it run for over four hours. Meanwhile, I ordered a replacement battery (S46B24R) from a local Toyota dealer, as the existing battery had been installed in 2021.

    When the new battery arrived, I installed it in the car, but the car still wouldn’t start. I jump-started it again and let it run for a couple of hours. This time, the car started fine, but the instrument cluster wouldn’t come on. I decided to put the old battery back in, and everything worked normally—the instrument cluster was functioning as expected.

    I went back to the dealer, and initially, they wanted to charge $165 for troubleshooting. After I protested, they tested the battery, confirmed it was faulty, and replaced it. I installed the new replacement battery today, and while the car started, the instrument panel still didn’t work. Once again, I reinstalled the old battery, and everything worked fine.

    What could be causing this issue?
     
    #1 tinkertwain, Jan 4, 2025 at 2:59 PM
  2. tinkertwain

    tinkertwain New Member

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    2008 Prius
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    Three Touring
    Only difference I see in the batteries is that the new battery measures 12.7 volts with multimeter vs the 12.4 volts for the old battery.
     
    #2 tinkertwain, Jan 4, 2025 at 4:50 PM
  3. Brian1954

    Brian1954 Senior Member

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    III
    #3 Brian1954, Jan 4, 2025 at 8:25 PM
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  4. Tombukt2

    Tombukt2 Senior Member

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    What's happening is is when you're changing the battery you're creating the problem that's going on on your CM monitor display which is where you look at your speed your gas gauge and your transmission selection It is just a coincidence that you are making this happen with each change of the battery but what happens is is when you take the negative terminal loose on your battery to change it and then you go to hook it back up if you want to make this work to prove this point when you're hooking up your new battery the new good one when you put the positive post on first now put the negative post on and touch it to the battery while the hatch is open and you're looking at your display on your dashboard You're looking to move the negative terminal until you see the door open symbol light up when you do lock down your negative battery terminal close the hatch open the door driver door see the symbol that the driver door is open when you sit in the car and push the button with your foot on the brake you will have a display guaranteed even with the new battery It's not the battery that's causing this It's three or four capacitors on the CM monitor display this is an old situation oldest dirt there's a company in Texas that specializes in this repair they built the business around it that's how old it is place is called Texas hybrids you can talk to them on the phone look at their video see all the nonsense and they'll walk you through everything you need to know and there's probably a hundred pages here on the subject
     
    #4 Tombukt2, Jan 4, 2025 at 8:40 PM
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