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2004 Prius Won't Start - Bad Hybrid Battery Pack?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 4restg, Jun 25, 2017.

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  1. 4restg

    4restg Junior Member

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    Hello. I'm new to the forum and looking for some advice about my 2004 Prius. As of today, the car won't start. I put in the "key" and press the power button, but nothing happens. Also, no dash lights come on, the power locks don't function and the dome light doesn't come on, so the car does not appear to be getting power.

    I pulled out the 12V battery and brought it to an auto supply store. They tested it and told me it was still good, so I've ruled that out. Because of the age of the car, I'm worried that the hybrid battery pack may be bad. This didn't just happen out of the blue. Here is how things progressed over time...

    -About 8 weeks ago while I was driving, a red exclamation point warning light in a triangle appeared on the dash display. Being descended from a proud line of Vermont rednecks, I chose to ignore the light and continue driving. Two days later, the light went off.

    -Flash forward six weeks. When I first tried to start the car it was totally dead, as described above. However, after two or three tries, it started.

    -Over the next two weeks, the not starting issue continued intermittently, becoming more and more frequent, which leads us back to today and the beginning of my post.

    Any advice is welcome. The other thought I had was could this be a bad starter, but given the push button ignition I have no idea if the symptoms would be the same as an old fashioned turn key kind of car. The progression does remind me of what I've experienced with that in the past (progressively more difficult starting until finally the car won't start at all).

    Thanks for the advice.
     
    #1 4restg, Jun 25, 2017
    bisco likes this.
  2. Texas Hybrid Batteries

    Texas Hybrid Batteries Senior Member

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    Dead 12 volt battery. If it's less than 5 years old you should try to recharge it, otherwise replace it.
     
    #2 Texas Hybrid Batteries, Jun 25, 2017
  3. bisco

    bisco cookie crumbler

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    welcome!

    did the auto parts store give you a printout?

    if the 12v is good, check the negative to body connection.

    your car does not have a starter. the 12v fires the dash lights, relays and computers. once you get the 'ready' light, the motor generator turns over the engine.

    if you got the red triangle of death, there is a troublfcode stored. have the auto parts store read it, but you might need toyota to scan it.

    how many miles on her?

    all the best!(y)
     
    #3 bisco, Jun 25, 2017
    Last edited: Jun 25, 2017
  4. 4restg

    4restg Junior Member

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    Thanks for your reply. Helpful to know it doesn't actually have a started. The car has 162,000 miles.

    I did not get a printout at auto parts store, no. However, I replaced the 12V battery about a year and half ago, so not the original.

    I will double check the terminals / connections but I thought they looked clean and well attached. If it isn't the 12V battery, can you think of anything else that would cause this?
     
    #4 4restg, Jun 25, 2017
  5. bisco

    bisco cookie crumbler

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    you can check the brake switch, make sure the lights come on when you step on the brake.

    the reason i ask is, the battery needs to be load tested, not just static voltage. they usually give you a printout of voltage and cold cranking amps.
     
    #5 bisco, Jun 25, 2017
  6. 4restg

    4restg Junior Member

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    Ok Thanks. I think I'll pull it out and get a second opinion somewhere. And I'll try the brake switch.
     
    #6 4restg, Jun 25, 2017
  7. dolj

    dolj Senior Member

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    You can have a good battery that is flat. However a flat battery is in danger of sulphating, and a sulphated battery is difficult to recover from. The longer the battery is in a flat state the more damage it will suffer. So get that battery on a charger immediately and get it charge to full, you just might get away with it. Otherwise you will be replacing what is a relatively new battery very shortly.
     
    #7 dolj, Jun 26, 2017
  8. Wilsid

    Wilsid Junior Member

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    Vehicle:
    2004 Prius
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    I had bad battery pack,one modual had gone bad replaced it,every thing back to normal.
    I did put 28 & 1 and so fourth in the middle. new modual out of a 2013 for $36 on ebay.
     
    #8 Wilsid, Jul 13, 2017
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