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Advise - Gen 2, Dealer says needs Hybrid Computer, maybe battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by CarlB, May 14, 2020.

  1. CarlB

    CarlB Junior Member

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    Hi all, my daughter's 2006 Gen 2 wouldn't shift out of park this morning, threw error codes. She had it towed to a Toyota dealer, they're saying it needs a new hybrid computer, maybe the battery. Battery was replaced recently with a rebuilt, but I know that's a risky business. (Guy had good local reviews.)

    Advice? Thinking the dealer wants to do the hybrid computer first, and when that doesn't solve it, the big ticket is the battery. Zap-zowie, lots of $$$ to them for a routine couple of jobs, I'm sure.

    There is an alternate battery source for Gen 2s, new built, correct? I'd need to find a shop conversant in Prius hybrid repairs to consider that - Minneapolis - St. Paul area. Especially if the hybrid computer is really shot.

    Probably need to have a course of action decided by tomorrow, the dealer will want to start the work or want me to get it towed out of there.

    Thanks much.
     
    #1 CarlB, May 14, 2020
    Last edited: May 14, 2020
  2. bisco

    bisco cookie crumbler

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    how many miles on her? have you talked to the battery installer?

    'newhybridbatteries.com' $1,600. call around, some dealers are under 2k for an oem

    member eric becky is in madison, he's a prius expert
     
  3. CarlB

    CarlB Junior Member

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    Lotsa miles - guessing about 150k perhaps. Was probably 2 years ago, the battery was replaced. I'll have to find the records, nothing in my emails unfortunately. Don't think the warranty went all that long. I was OK with getting a few years for $850, and that's what happened. He came out, installed, took the old one away, daughter was back up and running.

    But the hybrid computer that the dealer wants to start with - am I correct to wonder if that's really the best place to start?
     
  4. bisco

    bisco cookie crumbler

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    you are. it's a matter of reading the codes and troubleshooting with the service manual. some dealers are better than others
     
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  5. CarlB

    CarlB Junior Member

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    Found the transaction - it was FEB2019 for the battery swap ... Had a one year warranty. So few months out. Lasted a bit less than I hoped it would.
     
    #5 CarlB, May 14, 2020
    Last edited: May 14, 2020
  6. TMR-JWAP

    TMR-JWAP Senior Member

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    Since you have no easy way of reading codes, before you throw away a bunch of money, try disconnecting the 12v battery for a minute. That will reset all the ecus to default. Then reconnect it and see if the car will work.

    If it does work, then you most likely have a HV isolation fault. That code will prevent the car from going 'ready' after it is shut off. If the code comes in while driving, it will allow you to continue driving normally. But, once you shut the car off, it locks out the ability to go 'ready'. Luckily it can be reset by disconnecting the 12v battery. Some people have been known to install switches at the 12v battery to allow rapid reset and continue driving the car for years. This fault is usually caused by a minor electrolyte leak/seep from one of the battery modules. Obviously, HV battery replacement would solve the problem, as long as the HV battery was the source of the problem.

    Later years (after Gen 2) no longer have this fault lock out the car. It remains drivable.

    Other things to think about...

    If the dealer diagnosed the car, they should be able to provide a report of what the codes were, along with subcodes. You should get that info and post it.

    Don't get suckered into a bunch of repairs without having the 12v battery verified to be in good condition and properly charged. Remember, the Prius is a rolling computer where the computers work on a 12v battery. How well does your household desktop computer work if the wall plug is falling out? Similar situation for a Prius when it has a poorly performing 12v battery.
     
    #6 TMR-JWAP, May 14, 2020
    Last edited: May 14, 2020
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  7. ChapmanF

    ChapmanF Senior Member

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    I don't recommend driving forever on a reported isolation fault.

    The reason is that one leakage path to the chassis isn't much of a big deal; the computer can detect it, lets you know by a code, and you can (carefully!) open things up and clean it.

    However, if conditions were right for one leakage path to form, they are probably right for another one to form eventually, and that would complete a circuit. How far apart were the modules forming those two leakage paths would partly determine how much power gets delivered into that completed circuit.

    So, while the first code reporting an isolation fault isn't necessarily a hair-on-fire urgent event, I still recommend treating it as a "plan to get in there and take care of it" kind of event.
     
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  8. CarlB

    CarlB Junior Member

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    I'll call their repair center in the morning, get the error codes and subcodes, post them. Thanks!

    Take a VOM to the dealer, check the battery voltage while connected but off? If so, what should I see?

    If I decide to get the car out of the dealer's shop, I'll need to try the battery disconnect. What do I need, an adjustable wrench? Disconnect the +12V red terminal, or the black ground terminal, or both? Wait for ... 30 seconds (for any ECU caps to drain)?

    Hope that gets the car temporarily drivable, if so will have my daughter drive it to a shop that I got a good recommendation for.

    If that does nothing though, then a tow to the shop.

    Another option is to drive/tow it home. Have the battery service come out, put another rebuilt in - should last another year at least. Long enough for us to decide what to do about the car long-term. Not too expensive to "kick-the-can-down-the-road" another year ($850).

    All the above assuming it's not just a bad 12V battery, of course.
     
    #8 CarlB, May 15, 2020
    Last edited: May 15, 2020
  9. M in KC

    M in KC Active Member

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    To disconnect the 12v battery you need a 10mm socket, 3" extension and a 1/4 or 3/8" ratchet. Simply remove the negative grounding screw on the negative battery cable from the body. There is no need to remove either cable from the 12 volt battery's terminals. At the 4:34 mark in this video you see the negative cable


    Here are a couple of how-tos for the 12 volt battery test.
    .



    Get the codes and sub codes from the dealership's scan and report back as you previously indicated.
     
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  10. fotomoto

    fotomoto Senior Member

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    Gotta' know the codes.

    Suspect the battery first, Prius ECU's failure rates are very low (it's usually a burned out wiring connector to it).

    GOOD LUCK!
     
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  11. CarlB

    CarlB Junior Member

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    OK, from the dealer:

    The Battery ECU wasn't giving out the op-codes, no readings from it. Hence the suspicion that it needs to be replaced. Tech has it all apart now, ready for the job. If just do the traction battery now, but then turns out to need the ECU replaced also, additional $700 on top of ~$4000 (inc. taxes) for everything.

    Fault codes and subcodes:

    P3000
    C1259
    C1310
    U0100

    Checking in with a local independent repair shop also, recommended by an expert. Would be some sunk costs and the additional tow if going to the independent shop obviously.

    So ... anything jump out for folks here based on the above codes and the narrative from the dealer?
     
  12. ChapmanF

    ChapmanF Senior Member

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    The codes all look consistent with the dealer's story. P3000 is just the car's main coordinating ECU (it has different names in different generations) saying "hmm, something's up with the battery ECU". C1259 and C1310 are both from the brake/skid ECU and only mean "hmm, coordinating ECU told me something's up". I haven't looked up U0100 specifically, but U codes are always something-can't-communicate-with-something. And no codes in the list from the actual battery ECU.
     
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  13. dolj

    dolj Senior Member

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    Just another set of eyes on your throw a rebuilt in for $850 plan. For what you have already spent plus what you plan to spend you could replace with all new (aftermarket) modules from newpriusbattries.com. They are $1600 delivered to anywhere in 48 mainland states and 3-ear warranty, but some assembly is required. If you don't need to rush into a decision, this would be a better solution. If you are not up for DIY, NPB can recommend a local installer to do it for you. It could be worth a look. If TMR-JWAP's suggestion works for you, it could buy you some time too.
     
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  14. CarlB

    CarlB Junior Member

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    I'm having the car towed to the independent repair shop (experts in Toyota hybrids).

    I'll ask them about the "newpriusbatteries" modules, see how that compares to a new Toyota battery. I think the price for the new Toyota Battery is $1950, and comes with a considerable warranty. Compare that to the $1600 (+ shipping) and labor to replace modules in my existing battery though, and it may be about wash.
     
  15. bisco

    bisco cookie crumbler

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    i'd go with the oem at that price. either way, it will be substantially lower than the dealers 4k.
     
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  16. SFO

    SFO Senior Member

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    Have you spoken with @strawbrad already?
     
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  17. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    None of those codes confirm a bad battery. A voltage leak is the most likely source of the not going into drive problem but that code is not present.

    Did I replace the battery in Feb 2019? Can't tell from just your screen name.
     
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  18. ChapmanF

    ChapmanF Senior Member

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    They seem pretty consistent with a bad (or at least offline for some reason) battery ECU though.

    Specifically, the P3000 (HV ECU saying something's up at the battery ECU), combined with the battery ECU having nothing to say for itself.

    The U0100 is a communication error, but it's communication between the HV ECU and the engine ECU, so it's nothing directly to do with the battery, but might indicate some more general CAN flakiness going on.
     
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  19. CarlB

    CarlB Junior Member

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    Hi Brad, yes Feb 2019. You did a great job for us on a cold winter evening, we appreciated that! And maybe the pack is still going strong, if the battery ECU or the connections to the battery ECU went bad.

    OK the plot thickens. Tow truck comes to haul it over to the independent repair shop: "Did you know your catalytic converter has been stolen?" Dangly cut oxygen sensor wire, cut. Closer look, sure enough, cat converter cut out.

    As many here know, that's going to be an expensive fix. It might total the car.

    So where/when did this occur?

    Daughter would have noticed that on the Thursday morning drive she took to the parking lot with the engine trouble lights going, correct? Would be loud? When she gets back in, now the car won't shift to drive. Have to check with her if there was any time that she left the car on its own, between parking it (after seeing the failure lights) and the dealer's tow truck showing up. Edit: checked with her, there was 3 hours it was on its own in the Starbucks lot.

    Dealer says was car was indoors Thursday evening, but parked out back last night (Friday evening to this morning). Played surveillance tape, nothing showed up between three camera angles. So they don't think it happened when they had it.

    Question for those here: With the engine not running, would the missing oxygen sensor have been picked-up? (Hope that sensor doesn't go to the Battery ECU, if so we couldn't know either way.) Again the dealer reported failure codes were:

    P3000
    C1259
    C1310
    U0100

    But would the O2 sensor missing only have been picked up if the engine started?

    So, might be a bad Traction Battery ECU, Traction Battery might be OK as yet, might need a 12V battery at this point (so much relies on that and it's been 4 years since we purchased it). Add a cat-guard bolt-in (weld-in?) in, new cat converter and O2 sensor and sensor wiring (but depending if it can be proved stolen at the dealer's they may be on the hook). Insurance might decide to total an '06 with 180k (she's been driving it!!) if my comprehensive has to cover the cat converter. Ugh!

    Thoughts, observations, rule-such-and-such-outs, strategies, all welcome!
     
    #19 CarlB, May 16, 2020
    Last edited: May 16, 2020
  20. TMR-JWAP

    TMR-JWAP Senior Member

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    If your state has normal 48 state emission/inspection requirements, there are many places on ebay that sell replacement cat systems at reasonable prices. ~135 bucks for just the cat portion that bolts to the exhaust manifold and splices to the resonator or about 350ish for a complete assembly that bolts to the exhaust manifold on one end and bolts to the exhaust pipe at the rear passenger side just before it goes past the rear wheels.
     
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