Wow, a whole bunch of lights came on at once!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by madler, Mar 20, 2009.

  1. forrest_fire1

    forrest_fire1 Junior Member

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    :mod:All the lights went off about 50miles before we got to the Ontario Oregon toyota dealer. :mod:

    Service person said the lights probably came on due to loose gas cap or dirt in the gas cap seal/o-ring.

    Ok, that was all fine and dandy, but 4miles out of Boise Idaho we had ALL the lights come back on again.

    So, we are in the waiting room waiting for our $98.00 code check to find out how much we will owe on a repair...

    Sales person asked how many miles we have on our prius. I replied 127,000miles. He said "good testimonial".... I was like... hummm.
    Personally I think this car should go 400,000 with out a hitch... Maybe not....

    Well, still waiting:confused:... We will keep ya'll updated.
     
  2. mtagg49

    mtagg49 New Member

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    Had the same thing happen on my 2006 with 35k miles. The tow truck driver jumped it and followed me to the dealer. The dealer replaced the 12 volt battery, which seems to have solved the problem. Not sure why the battery would have died with the limited mileage on the car.
     
  3. madler

    madler Member

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    Really? Doesn't 12.5 V seem like the 12 V battery is good? It sounds good to me.

    The dilemma I face is that if it's not the auxiliary battery, I can get whatever is wrong fixed for free under my extended warranty. However that warranty doesn't cover the auxiliary battery.

    So, if I buy an auxiliary battery and that's not what it was, I could have just brought it in to be fixed for free and I needlessly blew $160 on a battery I didn't need.

    If I bring it in to be fixed and it is the auxiliary battery, I end up paying for the dealer to find that out, which I would like to avoid if I can figure that out myself.

    Therefore I would like to find a good way to tell for sure if the auxiliary battery needs to be replaced, without having to buy one first and try it out as a form of exploratory surgery.

    So does anyone know of an unambiguous diagnostic for a bad auxiliary battery?
     
  4. EZW1

    EZW1 Active Member

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    Understand something about the battery: 12.5V does not constitute a good battery. You are likely measuring your voltage under a no-load condition.When the battery gets tired, the full-load voltage will sag. Also understand that for the couple seconds between when you press the start button and when the inverter kicks in, the 12V battery is under quite a load when all the electrical systems come on. A good battery will sag a good volt during this time. A tired battery could sag far enough to not allow all systems to come up - and when that happens it looks like Christmas on your dash.
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    First, measure the battery voltage after several hours have elapsed with the vehicle IG-OFF, and see what it is.

    Second, note that a low battery voltage will prove the battery is definitely bad; however a high battery voltage does not prove the battery is definitely good. This is because battery state-of-charge and capacity are only loosely correlated with voltage.

    Your battery is already ~4 years old. Typically you would be lucky for the battery to last 5-6 years. So if you buy the battery "needlessly" now, instead of buying it one or two years from now, you might be giving up at most $50 worth of value on a $160 battery.

    Unfortunately, battery diagnostics are not unambiguous, based upon poster reports that their Toyota dealer found the battery to be OK, yet problems persisted and after the battery was replaced the problems went away.

    You've received numerous replies agreeing that the 12V battery is the most likely suspect. It's now up to you to decide whether you wish to accept that advice or not.
     
  6. madler

    madler Member

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    My first test was when the car hadn't been touched for a day. I got 12.48 V.

    As for the load condition, I found a nice built-in diagnostic on the MFD with instructions from one of the posters in this thread (Schumacher -- thanks) on another forum and ran that. It reported 12.5 V with no load, 11.9 V with load, and then 14.2 V with the car running. Still pretty close to the spec values.

    Anyway, I thought of an unambiguous test which I'm going to try. I will simply run jumper cables from a known good battery in another car, disconnecting the current auxiliary battery, and see if the panoply of warning lights still come on using the other battery.
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That's a reasonable test.

    I suggest that after disconnecting the 12V battery, you let a few minutes elapse so that all DTCs are lost and the ECUs can reset, before you connect the other battery. Good luck.
     
  8. madler

    madler Member

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    I did, and the car forgot a lot of other things as well. (The time, the radio stations.)

    In short, it's not the auxiliary battery.

    I disconnected the auxiliary battery, waited a while and then ran jumper cables from the other car to replace it. I ran the same tests, and noticed that the other car's battery wasn't even in as good shape as the Prius's, since in the load condition the other car's battery dropped to 11.4 V instead of 11.9 V when I did it with the Prius's battery.

    So I started the other car and let it run, effectively providing a very high capacity 14 V auxiliary battery. Then the all of the off, load, and charging conditions never got below about 13.6 V.

    I was nevertheless consistently greeted with the christmas tree of warning lights.

    So it's not the battery. Off to the dealer it goes, with the extended warranty in hand.

    Thank you all sincerely for your help. This priuschat thing is really useful.
     
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Thanks for the update, you used a clever approach to rule out the 12V battery. It'll be very interesting to find out what your dealer discovers. Good luck getting your car promptly repaired under warranty.
     
  10. madler

    madler Member

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    They replaced the Skid Control ECU, and now the car is all happy again.

    It was fully covered under the extra care warranty, so I payed $0. (They would have also payed for a rental car during the repair, but I didn't bother.)
     
  11. madler

    madler Member

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    In looking into what the Skid Control ECU does, I found that to do its job, it communicates with the HV ECU (high voltage) to modulate the power to the wheels and the EPS ECU (electronic power steering) to allow steering assist, both for vehicle stability control.

    So when my Skid Control ECU failed, it is plausible that the HV ECU and EPS ECU both called foul as well due to a lack of information or proper signals from the Skid Control ECU, leading to all the warning lights. The Skid Control ECU failure caused the brake and ABS lights to come on, the HV ECU then caused the hybrid warning to come up, and the EPS ECU caused the power steering warning to come up.
     
  12. jayman

    jayman Senior Member

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    Fun how it can be a real adventure tracking down these codes sometimes
     
  13. madler

    madler Member

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    Just looked at the paperwork. That repair cost $1700! To Toyota insurance that is. The Skid Control ECU by itself was $1400, plus tax. That $985 Extra Care Service Agreement sure paid for itself.

    There are a lot of ECUs in the car. I wonder how much it would cost to buy every computer in the car as parts, and how that would compare to the cost of the car.
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, it seems that on average the ECUs will cost around $1K each, so buying salvage parts would be the way to go once the car is out of warranty.

    My dad's 2007 also needed a new skid control ECU, but in his car's case the brakes were acting up so that pointed more definitely in the direction of that ECU.

    Glad that your car was repaired without difficulty. Can you please post the DTC logged by your car?
     
  15. madler

    madler Member

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    I think I'd need a gizmo to plug into the framistam port in order to know that.
     
  16. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Pls check your repair invoice to see if the DTC were recorded. Frequently the tech will provide this info. Thanks!
     
  17. richard schumacher

    richard schumacher shortbus driver

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    You lucked out with the extended warranty. That's one :_>
     
  18. madler

    madler Member

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    Alas, no.
     
  19. forrest_fire1

    forrest_fire1 Junior Member

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    Turned out to be the inverter water pump..
    The diagnostic test was $98.00 and the repair came to about $275.00. The water pump is about the size of a coffee cup. This pump is located under the car and pumps water to cool the inverter which is used to convert direct current into alternating current.
    We found out about the problem in Ontario Oregon, but drove all the way to North Platt Nebraska to have the pump ordered and installed. We took it easy when the computer said we were using energy from the batteries for long periods of time, like long up hills.
     
  20. KCPrius

    KCPrius Member

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    That was the same thing that happened with my wifes 05...all the lights came on, then went out a while later. Water Pump. My lights never turned on, but there was leakage under mine (in the garage). It was also the water pump. They told my wife that there were issues with the water pump and Toyota extended the warranty for it, although hers was beyond that limit.
     
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