Check Engine Light On - Dealer Can't Find Cause

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by yadax3, Jul 27, 2012.

  1. yadax3

    yadax3 Member

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    A month ago my check engine light came on so, after checking to ensure the gas cap was screwed on correctly, I did what the manual recommended and took my car directly to the dealership. After paying a $49 diagnostics fee and losing my car for an entire day while they ran tests and contacted Toyota, my dealership told me they couldn't find a problem and just reset the indicator. Within a few days the light came on again but before I had a chance to take it back to the dealership it went off. Now some 3 weeks later it is on again and I'm wondering what to do. I certainly don't want to keep paying the dealership $49 to just reset the indicator. If I ignore it then I rendor it useless - or worse. Any advice?
     
  2. toyotechwv

    toyotechwv Toyota Technician

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    What is the code that it sets? How many miles on the car?

    PC36100 ? 2
     
  3. GrumpyCabbie

    GrumpyCabbie Senior Member

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    What miles are you at? Do you use the car often or is it frequently sat around doing nothing?

    What I'm getting at is have you checked the 12v? It might be early for it to fail but it might be worth checking it.
     
  4. yadax3

    yadax3 Member

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    43K miles and I don't know where to look for a code. Does it display somewhere or do I need to ask the dealership?
     
  5. toyotechwv

    toyotechwv Toyota Technician

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    You should have asked for the printout from Techstream before you left the dealer.

    PC36100 ? 2
     
  6. yadax3

    yadax3 Member

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    Also, my car is used virtually every day except when we've taken vacations - usually 7 to 10 days at a time. When the light came on originally the car had been in use every day. It was sitting for about 8 days until late last week when I started driving it again, shortly after which the check engine light returned. I did not refill the gas tank in the interim so I eliminated that possibility.
     
  7. bubbatech

    bubbatech Member

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    At 40K, it is possible that the 12V battery is failing, which could cause occasional errors. Nonetheless, it does not bode well for the quality of your dealership that they would just throw their hands up in the air and punt. I suggest that you persist with them. They may have concluded the original issue was just some random error. THat it has recurred definitively shows that it was not.
     
  8. yadax3

    yadax3 Member

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    Hold on - I think I found it on the receipt. It says, "Found code P0401 EGR low flow detected. Checked the operation of the EGR system. No issues found. Active tested the EGR system. Found it to be working as designed. Cleared the light."
     
  9. toyotechwv

    toyotechwv Toyota Technician

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    Just checked and there are no TSB's for this code. Sounds like they followed the flow chart, step 2 is active test system. May be sticking egr valve or carbon deposit clogging the system. I would take it back and tell them to further diagnose the issue and create a TAS case with tech assistance.

    PC36100 ? 2
     
    josh2008 likes this.
  10. Fore

    Fore Don't look back!

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    If your car is still under warranty you shouldn't have to pay a dime.
     
  11. yadax3

    yadax3 Member

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    Thanks. But what's a TSB and a TAS case?
     
  12. toyotechwv

    toyotechwv Toyota Technician

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    PC36100 ? 2
     
  13. Mike500

    Mike500 Senior Member

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    The OBDII code doesn't say everything.

    Any small intermittent vacuum leak, especialy in a gasket or a vacuum hose" can cause an intermittant "check engine light." The check engine light only stays on, when the condition occurs a certain number of times over a certain period of time. Once on, it may stay on and may even turn off by inself.

    Since they can occur when only a series of specific condition are met in the operation of a lot of vehicle systems, they can be very hard to find, unless there is where, at some point, the condition becomes permanent.

    I'd get an inexpensive OBD II reader, so you can check the code, and reset it, yourself, in necessary. They can be had for about the $49 tat you paid to the dealer, and maybe, even less.
     
  14. frodoz737

    frodoz737 Top Wrench

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    If the code came back, you will not have to pay for further testing. Don't let the Service Writer BS you. Even nuisance faults have a cause and resolve. Follow Toyotechwv's advice, they have Tech Assistance for a reason.
     
  15. yadax3

    yadax3 Member

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    My emissions system is still under warranty but I still had to pay since they couldn't figure out what was wrong. I wonder how much more testing is going to cost me.
    Hi again,

    Welp, I took my car back to the dealer again today and they called with the diagnosis/estimate a few minutes ago - $539 to replace the EGR valve, which (after talking to Toyota) they characterized as the 'next step'. Wow. I've never paid out so much money to repair a car that is practically new. I know it's out of warranty but I've always purchased cars that are rated very reliable to avoid being in this situation, especially when I'm still making payments. Should I just suck it up and find the money to pay the bill or should I be asking more questions?
     
  16. tedjohnson

    tedjohnson Member

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    I would get one from a wreck and have an independant mechanic swap it out. Usually only 2 bolts, altho I have never done a Prius...
     
  17. spiderman

    spiderman wretched

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    Geezzz I am surprised you all didn't recognize that code, it is the "my dealer needs more money" code.

    Sorry to hear about the situation, but I don't see how the EGR is not covered under warranty.
     
  18. toyotechwv

    toyotechwv Toyota Technician

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    Call the Customer Experience Center and ask for goodwill assistance. If you have been returning to the dealer for service since purchase then they will probably consider it. Maybe a 50/50 on the repair or one party pay for parts the other for labor. We do it all the time for loyal customers who aren't far out of warranty. 1-800-331-4331

    If they won't assist you, then I would try to find a part from a wrecked Prius instead of buying new.
    PC36100 ? 2
     
  19. yadax3

    yadax3 Member

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    Thanks, but I don't typically get my service done at the dealership - too much of a hassle so I don't know how successful I'd be with goodwill assistance. I'll give it a shot though. Meanwhile, I found an OEM EGR value online for $231 and my hubby is pretty handy. He retrofit my fog lights. How difficult is it to replace an EGR valve?
     
  20. yadax3

    yadax3 Member

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    BTW, I'm also going to look around for a 'junked' EGR valve next week. I actually totaled my first 2010 Prius almost 2 years ago - maybe I'll find it at a local wrecking yard!?!
     
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