check engine light

Discussion in 'Gen II Prius Technical Discussion' started by Tamim, Sep 14, 2009.

  1. Tamim

    Tamim Slayer of Nug

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    Hey guys i'm pretty bummed out, I just bought a 2005 Prius with 72,000 miles on it, I have driven 2500 so far and now the check engine light has come on.

    What should I do? I like to try and fix things my self but I have a feeling I will have to take it to the dealership wont I? Hayes manual wont cut it?

    Thanks for the advice guys.
     
  2. northwichita

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    hm... Autozone close by? They do free checks.
     
  3. JimN

    JimN Let the games begin!

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    Since you DIY what codes does your ScanGauge or other reader report?
     
  4. 13Plug

    13Plug Active Member

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  5. jdenenberg

    jdenenberg EE Professor

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    Autozone will check your codes for free, but their computer may misinterpret the meaning of the code. You need to look up the Toyota specific meaning of many of the codes (or ask here after getting the codes).

    JeffD
     
  6. Tamim

    Tamim Slayer of Nug

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    Hey guys the check engine light seems to of turned its self off? Then a couple of hours later it turned on again, and now its off which seems like for good?

    What is this ScanGauge you speak of and where can I get one that works on my car?
     
  7. boppo

    boppo Active Member

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  8. richard schumacher

    richard schumacher shortbus driver

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    The engine can destroy itself pretty quickly. Take it to a dealer.
     
  9. Tamim

    Tamim Slayer of Nug

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    Hey guys I just checked the light and it gave me code P1121

    I looked it up in my Prius repair book that I just got and it said the following


    Coolant Flow Control Valve Position Sensor Circuit Stuck
    -water valve (control flow control valve)
    -cooling system (clogging)


    I think I saw a service bulletin up here for something like this, does any one know if this is possibly covered by warranty or if this is a hard repair for me to undertake?
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I suggest that you search for the TSB to see whether the repair is covered under the CA emissions control warranty or not. The powertrain warranty expired at 60K miles.

    It is certainly possible for you to replace the valve yourself. This controls flow of engine coolant to the coolant heat recovery canister. Should you decide to do so I suggest you invest $15 in techinfo.toyota.com so that you can access and download relevant repair manual pages.

    The hardest part of the procedure will be to drain and replace the engine coolant as it is not easy to get air out, with the coolant heat recovery canister, valve and pump in the system. I've previously posted how to DIY.

    If you DIY I recommend that you continue to use the pink Toyota Super Long Life Coolant which costs around $22 per gallon. You'll probably need a couple of gallons.
     
  11. Tamim

    Tamim Slayer of Nug

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    Looks like its not covered under warranty any longer :(

    Would techinfo.toyota.com be a better source than the Bentley manual I just received?

    I'm gonna give it a shot and try to do the job my self, I'll tell you guys how it goes or if I electrocute my self in the process

    Where can I get some of that pink Toyota fluid you speak of?
     
  12. David Beale

    David Beale Senior Member

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    The fluid is only available from Toyota dealers. You can also buy it online (e g Toyota Scion Parts Accessories Discounted Prices - Metrotpn). I'm pretty sure it's just polypropylene glycol, but the additive package may be special, so best to use the Toyota fluid.

    It would be very difficult to "electrocute" yourself with a Prius. You'll have to try very hard if you want to do that. ;) The high voltage battery is -completely- disconnected from the car when you turn the car off, and when the car is on it's got ground fault protection on both the +ve and -ve leads.

    You'll have to determine if it's the pump failing or the valve that's sticking. The manuals available from the Techinfo site tell you how to determine that.
     
  13. Tamim

    Tamim Slayer of Nug

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    I'm having trouble finding what I'm looking for on techinfo, can only one suggest some search terms I should try on that site?
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I suggest that you start by finding the repair manual for your model year. Then find the diagnostics section of the manual and look up your DTC which is P1121.

    Download the pages that relate to that DTC. Note the possible trouble areas which include the valve and maybe the coolant heat recovery pump.

    Then find the pages that relate to the engine coolant system and download the pages that explain how to remove the valve and the coolant heat recovery pump. Also download the pages that explain how to drain and refill engine coolant.

    Read those pages and note where there are references to other things that you have to do to gain access to those parts like removing the engine under covers, etc. As necessary, find and download the other pages that you will need.

    Regarding the engine coolant drain/replace procedure, also see my post about how to do that (which involves shorting terminals in the CHRS relay socket to force the pump to run) and decide for yourself whether my procedure will work for you or not.

    No one said it was easy to use techinfo, that is why they charge only $15 for two business days... The manual has > 4,000 pages, lots of excellent info if you have the patience to find it.