Inverter Replacement: 2002 Prius

Discussion in 'Generation 1 Prius Discussion' started by RW5207, Sep 12, 2011.

  1. RW5207

    RW5207 Junior Member

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    Well, I just got a confirmation on my P3125 error code by the Toyota dealer on my 2002 Prius...it's the inverter. Says it will cost $4400 to replace.

    I know I can purchase a new replacement part for about $2500, but I've already purchased a salvage unit for $300, so I'll be trying that first.

    Has anyone documented this procedure? I am planning on documenting it as I go and will post it on my blog at Idoneitmyself on wordpress. However, if anyone has some documentation to follow it would be nice to review it prior to my work. I've been searching the web and can't find anything, so let me know if you are aware of something that might help.

    I'm also planning on getting the shop manual downloaded. If anyone has the chapter on this, I could use it.

    Thanks...Russ
     
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  2. RW5207

    RW5207 Junior Member

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    Well, I guess the answer is "no." Okay, so I did it yesterday and documented my procedure on my blog. Unfortunately, I don't have enough posts to put a stupid link in this post (that's an interesting rule). So, you can find it on my blog on wordpress.

    The name of the blog is Idoneitmyself dot wordpress dot com.

    The name of the post is replacing-the-inverter-assembly-on-a-2002-1st-gen-prius.
     
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  3. seilerts

    seilerts Battery Curmudgeon

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  4. RW5207

    RW5207 Junior Member

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    Thanks for the URL post!
     
  5. RW5207

    RW5207 Junior Member

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    FYI, this 2002 Prius has about 118,000 miles on it...almost all city driving.

    Okay, so I replaced the inverter with a salvage unit and have some other "issues"
    that I've been working on.

    I was concerned there might be a problem with the inverter coolant pump (although I'm positive it was operating prior to the replacement, because I could see the coolant level high/low in the reservoir when it was pumping) so I went ahead and ordered a new one and replaced it. I've been working on getting the air purged and I believe I've done it using the "start the pump, stop the pump, open the air bleed valves" procedure and, in addition, using a hand-operated brake bleeder vacuum pump to also suck the air out through the bleeder valves.

    All was working for my short drive through the neighborhood and I was about to try a longer drive when it threw a code. I got the "triangle" and put it immediately back in the garage. During my short drive, it was recharging the traction battery and I watched the display go from fully discharged (got the "turtle" icon in reverse) to fully charged (with no more "turtle" icon in reverse).

    So, I'm going to borrow the scan tool from Autozone again and see what the code is. Will do that later this evening.

    If anyone has any experience/comments, I'm all ears.

    Thanks...Russ
     
  6. RW5207

    RW5207 Junior Member

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    Got the scan tool and have recevied a number of DTCs, p3006, p3191, p3016...I'm sure there will be others.

    Scanning the forum, I see I might have issues with the traction battery and/or ECU. I'm guessing the battery. However, before I go there I'm going to get the auxillary battery tested to insure I don't have a low voltage aux battery causing weird electrical problems.

    If I do need a new traction battery I see that several people have rebuilt their batteries by purchasing cells on the internet. Is it possible to purchase all new cells and start fresh? I'm concerned purchasing used cells would simply give me a problem next year. Or, are the newer cells so much better that they never fail? :)

    Trying to get my baby going again...
     
  7. RW5207

    RW5207 Junior Member

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    Oh, and by the way, when I took the car to the dealership in Richardson, Texas, they diagnosed the inverter as being the problem and were all ready to replace it but really wanted to sell me on cleaning the throttle body.

    I took a look at the butterfly in the throttle body and operated the throttle by hand and didn't notice anything binding. Just for grins I shot a little carb cleaner on the throttle body butterfly plate to clean it off, but it really wasn't bad looking at all. In fact, it was still shiny.

    Another attempt to upsell in a depressed economy? Or, simply another attempt to upsell?
     
  8. seilerts

    seilerts Battery Curmudgeon

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    P3191 is a no-start, probably due to the P3006 and P3016 battery codes. The real issue is P3016. This is due to a malfunction in battery block #6. You have several options, listed here in order of highest cost/longest life.

    1. Battery from Toyota. MSRP $2300+tax+core. Are the modules new or reconditioned? Good question.
    2. Reconditioned battery from ReInvolt made w/Gen II modules. $1675+shipping+core. This is less compelling since Toyota lowered their battery prices. But unscrupulous dealers will charge in excess of MSRP so watch out.
    3. Build your own pack with newer cells. Get a fresh Gen II pack from a junkyard, and get 10 Gen II cells from JeffD PriusChat Forums - View Profile: jdenenberg. If you buy a charger to recondition the junkyard pack, then the expected lifetime is the same as #2 but you will have spent less than $1000.
    4. Buy two known-good Gen 1 cells on ebay (from Reinvolt) and replace the pair at #6. Cost $30. Or buy two pairs for $50. This will get you another year or two.

    Reinvolt's ebay store: tautomotive | eBay

    The throttle body cleaning would have been legit if P3191 was present with the P3125 when at the dealer. It is a common problem regardless so it is hard to find too much fault in that recommendation.
     
  9. RW5207

    RW5207 Junior Member

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    Thanks for the great info! I need someone to bounce my ideas off of, as I don't think the dealership would be very willing to participate in my dialog. Also, I'm not sure they really have much experience.

    So, the simplest thing would be to replace the cells in position #6. Can this be done with Gen II cells or, if I take this approach, must I use Gen I cells?

    There's a part of me that just wants to purchase a new battery from Toyota and be done with it (assuming that fixes the problem).
     
  10. RW5207

    RW5207 Junior Member

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    So I guess the question is, would a "new" battery from Toyota use the newer cells or would they still use the older cells? That might make me decide to go with a rebuilt battery that uses the newer cells.
     
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    It is true that a potentially simple repair would involve replacing the failed module(s) with used G1 modules. It would be difficult to use G2 because the physical location of the terminals is slightly different. The ultimate longevity of this repair is questionable as other modules may fail in the near future, while the used G1 modules to be installed are 8-10 years old as well.

    The new battery from Toyota would use the G1 design. It is not clear whether the new G1 battery modules benefit from lessons learned when developing the G2 modules, or not.
     
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  12. RW5207

    RW5207 Junior Member

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    Thanks, Patrick.

    If I replace an individual cell, I may be doing it again in the next few months. Plus, I'll be replacing it with old cells, so that looks risky.

    I'm thinking the most expedient way to do this is to purchase a rebuilt pack with Gen II cells. Can I save much money putting it together myself?

    Also, how much does a pack weigh? 38 cells @ x lbs/each + misc weight = ??

    Thanks again...Russ
     
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Russ,

    Yes, you could potentially save money by DIYing a pack, if you can deal with the safety issues associated with high voltage. Consult techinfo.toyota.com for repair manual info regarding how to remove and replace the traction battery.

    You would have to buy two 2G traction battery assemblies, which each contain 28 modules. Then you would select 38 modules out of the 56 for use in your Classic traction battery assembly. This would leave you 18 spare modules which you could potentially resell on eBay to lower your net cost.

    One possible complication is if the 38 modules are at differing state of charge which would require you to discharge them and recharge to the same level. The traction battery ECU will log a fault if it detects substantial module pair voltage differences. A difference of a few tenths of a volt may be sufficient to cause a fault.

    The weight of a Classic battery is ~118 lb.
     
  14. seilerts

    seilerts Battery Curmudgeon

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    Just to chime in again,

    You need only buy one Gen II traction battery, then 10 cells from jdenenberg. But be advised that this will be the most time consuming approach. If you just want a quick and dirty fix that might last for a year or two, then just replace the bad modules with good ones harvested by ReInvolt. If you take this route, then it would be a very good idea to pull the battery out of the car, let it sit for a week, and look for modules with high self-discharge, and replace them too. If you post voltages at T=0 and T=7 days, we can help you figure that out.

    The dismantling guide for Gen II is very informative. Find it here: http://www.eaa-phev.org/images/d/df/Priusdisman.pdf

    The traction battery autopsy thread is also a very good source of information: http://priuschat.com/forums/generation-1-prius-discussion/84017-nhw11-traction-battery-autopsy.html

    The ecu will look for a difference of more than 1.2V from highest to lowest before it decides to throw a code. This usually cannot happen on a random battery pull unless it has been sitting for a very long time, or there is a bad cell.
     
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