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Prius 2004 Check Engine Light

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by MikeM95831, Jun 19, 2010.

  1. MikeM95831

    MikeM95831 New Member

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    Vehicle:
    2004 Prius
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    N/A
    This is my first post here, but I've been reading for a while.

    I have a 2004 Prius with Nav and smart keys. My wife uses this as her daily commuter. We are the second owners, since December 2009, the first being my parents.

    The other day, she called me and told me that the red triangle of doom was lighted, along with the CEL, the brake warning, the VSC, and the car being bandsawed in two. I told her to check the tire inflation, which didn't help.

    Reading in all these posts, it looked like changing the 12V battery might do the trick, and since the one in it was the original and we were about to leave on a 2,000 mile trip, I changed it. That went fine.

    Check engine light stayed on for another day, then it turned off. Yay!

    Well, it's back. And it's intermittent. I hooked up my Equus 3100, and it says "Err". This code scanner works fine on my other cars. So now, I'm not feeling confident.

    How do I read the code if the code scanner thinks there's an error? What if it's the ECU? Has anyone else had this issue?

    By the way, I suspect the inverter coolant pump, but, of course, I can't confirm that. All the places around here that used to give free code scans have stopped doing that. Dealer wants to charge $57 to hook a scanner to it for 20 seconds, and I'd need an appointment.

    Any advice what my next step should be?
     
  2. 13Plug

    13Plug Active Member

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    Does that code scanner read CanOBD codes? Try another scanner, or have a place like AutoZone read the codes.

    Once you have the code(s) post them here or look them up at OBD-II Trouble Codes - DTC Codes Car Repair
     
  3. gur193

    gur193 New Member

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    i have an 2002 prius whenever i start ac and lights on the warning sign comes on and check engine light also come on and now i stop using ac and lights and after 1 or 2 days every thing is fine. if i do not do so the screen start blinking and car switch off and i have to stop. i think 12 volt battery is the problem .one day it switch off i put my jump start and the warning and check light was there but car starts and keep moving for 50 miles. what is all this what i do can any body help me . i also change the battery. but it happens whenever i needs ac or lights.
     
  4. MikeM95831

    MikeM95831 New Member

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    My scanner is not for CanOBD2. I just got one that is CanOBD2, and I get the same error.

    I should note that my older scanner works on a 1996 Maxima and a 2002 Ford Escape.
     
  5. MikeM95831

    MikeM95831 New Member

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    Fiddled with the new scanner some more, and finally pulled a code:

    P0A93, which according to Innova, sounds really bad; "Drive Motor ""B"" Performance".

    Okay, how large are the alligators in my swamp? Or do I just need to change a water pump?
     
  6. djasonw

    djasonw Active Member

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    Location:
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    Vehicle:
    2004 Prius
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    N/A
    Every time I see a post that is from a 2004 I get nervous as that is the one I have. I have over 108,000 miles and I know I am going to start needing to perform some heavy duty preventive maintenance.

    I know that within a few day's time you'll have some more input into what those codes actually do mean. As long as the car is performing fine, I think you're ok with driving it local. As for that big trip, well, I would make sure that those codes are clear and Toyota (or other mechanic) gives you the green light so to speak.
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I understand that you have installed a new 12V battery. Measure the voltage across the 12V battery using a digital multimeter, when the car is READY. It should be 13.8VDC. If much lower, then the DC/DC converter within the inverter is not working.

    If the voltage is incorrect when the car is hot, see if the voltage is correct when the car is cold. If so, then the inverter water pump probably needs to be changed. If the voltage is low even when the car is cold, then the inverter needs to be replaced. If you don't hear the inverter coolant pump running (near the driver's headlight) or see turbulence in the inverter coolant reservoir, then the pump is probably not working.

    Yes, you most likely need to replace the inverter coolant pump. See if you can hear it run and if turbulence is evident within the reservoir when the car is IG-ON, as described above. I posted here regarding how to replace that pump: http://priuschat.com/forums/gen-ii-.../65173-how-replace-inverter-coolant-pump.html
     
  8. MikeM95831

    MikeM95831 New Member

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    Thank you, and everyone else who responded.

    Test driving this weekend, the car is 100% reliable when the A/C is off, but after about 10 minutes of freeway @ 70 mph, with the A/C on, all the warning lights come on, the cruise-control drops, etc. I think it's this pump.

    I've never had one of these very far apart, so I do have a question. Is it easier to get to the pump if the driver's side headlight is out, or is getting it out a monumental task?

    I wouldn't dream of driving from Sacramento to Vancouver, BC with this problem. To quote Lester Burnham, "Honey, that's just nuts." I'm sure Roseburg is a wonderful community, but I don't want to get stranded there for 3 days when I should be in Richmond.
     
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I managed to get the pump out while the headlight was installed. It might be easier to remove the headlight first.
     
  10. MikeM95831

    MikeM95831 New Member

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    I've been trying to find an answer to this one, but since Toyota has a TSB on this one, and the failure of this one relatively cheap part can result in the rest of the drivetrain having a huge, expensive, catastrophic failure that might result in sending the car to salvage, I wonder why this isn't yet a recall item. I intend to keep my receipts so that when Toyota eventually makes this right, I can get reimbursed.

    I've often wondered why our Nav-equipped cars don't have a "Dashboard" function. Switch to that mode, and you'd get coolant temps, oil temp, oil pressure, engine rpm, motor rpm, motor/engine "splits", maybe even any DTC codes that are present, and so forth.

    Anyway, just thinking out loud. I plan to buy this part and replace it tonight. Wish me luck!
     
  11. MikeM95831

    MikeM95831 New Member

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    Well, I got mine installed last night. Pretty easy job. Thanks for all your help. I can't believe some dealers are charging $500 P&L for a job their rookie tech should be able to do in an hour.

    I saw the shiny new bracket and the dirty old bracket and tried to get the dirty old one out. I quickly realized it was pointless and a PITA, so I stopped trying after about 2 minutes.

    Don't tell anyone. It'll be our little secret.

    Is the pink antifreeze from the Toyota dealer at $20/gallon any different from the green stuff from Kragen for $8?

    Should the AL ring in the drain plug be changed? If so, I'll make an effort to do that (knowing, of course, that I'll have to replace a bit of the coolant I'll lose).
     
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    :eek:

    Yes. Do not use the "green stuff". Only use Toyota Super Long Life Coolant. $20 is a pretty good price.

    The aluminum washer should have been replaced, but if you didn't do so and don't see a leak then there's no point in removing the drain plug now, just to replace the washer.