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12 volt battery and ignition coil replacement

Discussion in 'Gen II Prius Main Forum' started by jonsmilburn, Jul 7, 2010.

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  1. jonsmilburn

    jonsmilburn New Member

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    I have seen the post for replacement 12 volt battery

    I can't post link, because this is my first post, but it would show up on a battery AND Optima search.

    Has anyone found a better price than elearnaid.com? Currently $165 for D51 Yellow top Optima with free shipping and installation kit. Also can't post this link, but viewable on link that would show up on above search.

    Also, can anyone recommend an ignition coil and good price source. I have seen them online anywhere from a WSO coil for $43.95 to YEC coil for $107.95. I have replaced the spark plugs and noticed some light burn marks on the outside of the coil from cylinder 2. Some slight rough running on the highway. Mileage slightly down. May be combination of low battery (showing 10.1 volts on display test) and burned coil.

    2005 Prius Original Owner 170,000 miles.
  2. dogfriend

    dogfriend Human - Animal Hybrid

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    I would just replace the 12v battery first and see if mileage improves. The low battery will reduce mileage by taxing the HV battery more than usual.

    My opinion on the coil would be to stay with the OEM part, especially if you are just replacing the one coil.
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  3. jonsmilburn

    jonsmilburn New Member

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    Do you know who manufactures the coils for Toyota? The following is what I see listed on Autopartswarehouse.com. Standard says "direct fit OE replacement" and Replacement says "Direct OE replacement". Standard and Replacement being the manufacturers. Do those terms mean OEM? Or is this just a loose translation?
  4. Qlara

    Qlara New Member

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    Is the Yellow-top Optima 12V battery the only best replacement option?
    How about the OEM 12V from Toyota? It probably won't be the cheapest, but had anyone gone that route for battery replacement? (At least it'll be 100% fit without modifications like the Yellow-Top)
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I agree with dogfriend that it would be wise to purchase the Toyota spark igniter. It doesn't cost very much, $73 here: Champion ToyotaWorld

    Regarding 12V battery replacement, I bought the original equipment battery for $139 from one of the Tucson Toyota dealers this past fall, when replacing the battery on the 2004 as a preventive move. I personally don't see the point of having to install the larger battery terminals, etc. <Already went through that drill when replacing the 12V battery on my 2001 a few years ago.>
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  6. Qlara

    Qlara New Member

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    Thanks Patrick for the OEM 12V battery insights and pricing.
    I may go for OEM when the time has come too.

    Out of curiousity, is this OEM 12v exclusive for Prius (including 2010?) or it's also be used by other Toyota/Lexus HS hybrids too?
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I believe that the 12V battery is exclusive for 2G Prius and also fits 3G. Highlander Hybrid uses a wet cell battery, not AGM. Not sure about Camry Hybrid.
  8. dogfriend

    dogfriend Human - Animal Hybrid

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    I think that if it was an actual Toyota part, they would say so. If they say anything else, then it is probably an aftermarket part.
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  9. roverguy78

    roverguy78 Elite Lurking Member

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    I don't really think you can go wrong with either battery, but the Optima will hold up much better to potential discharge situations that would easily damage the stock battery.
  10. jonsmilburn

    jonsmilburn New Member

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    Thanks Patrick. Got the Toyota 12 volt battery from a dealer nearby. Had to call around quite a bit. They ranged from $189 to $147. Got it in OK, but my "!", ABS, and VSC and Brake lights are still on. Pads and shoes look fine. Is there a reset button or mode for these lights. I was under the impression that the display voltage test of 9 volts (dying battery) was causing the lights to come on. Just want to make sure there is no reset on the lights (like after an oil change) before I move on to other testing or the mechanic. The other symptom I've had along with these lights is the yellow arrows coming from the battery don't stop when I come to a stop. I have to put in neutral or park to get them to stop not matter how hard I press on the brake. This happened a couple years ago, along with the lights above, but went away. I wrote it off at the time to a bad connection somewhere.
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes. First, retrieve the DTC:

    Make the car IG-OFF. Find the DLC3 connector (aka OBD-II connector) which is below the steering wheel column.

    Note that the connector has 16 terminals and has a trapezoid shape where one base is wider than the other. When looking at the connector so that the wider base is at the bottom, the numbering starts with #1 on the bottom right, and continues to #8 on the bottom left. #9 starts on the top right and continues to #16 on the top left. Put a jumper wire between terminals 4 and 13 and make the car READY.

    Look at the Brake Control (amber circle with ! within), ABS and VSC lights. If they produce a two-digit blink code, note what it is and post.

    If normal, the light will blink at 0.25 second intervals after a pause of 2 seconds.

    If a blink code will be logged, there will be a pause of 4 seconds, then the first digit of the blink code will come on as 0.5 second flashes followed by a 1.5 second pause. Then the second digit of the blink code will come on as 0.5 second flashes. If more than one blink code was logged, the second code will appear after a 2.5 second pause.

    After you've logged which light is producing the blink code and what the code is, you can clear the code by leaving the jumper wire in, making the car READY, then depress the brake pedal at least 8x in five seconds. Make the car IG-OFF and remove the jumper. Make the car READY and confirm that the warning lights are off. If the lights remain on, then codes remain present and this means the fault which provoked the codes is still present.
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