Welcome to PriusChat

We'd love to have you join our community and participate in the conversation! Sign up for FREE today.

Sign Up

check engine light

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

Social Buttons

  1. Tamim

    Tamim Slayer of Nug

    Joined:
    Sep 5, 2009
    Messages:
    33
    Likes Received:
    8
    Location:
    California
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    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

    northwichita .

    Joined:
    Sep 24, 2006
    Messages:
    454
    Likes Received:
    82
    Location:
    Wichita KS
    Your Vehicle Year:
    2004 Prius
    Model:
    N/A



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

    JimN Let the games begin!

    Joined:
    Nov 26, 2006
    Messages:
    5,401
    Likes Received:
    425
    Location:
    South Jersey
    Your Vehicle Year:
    2010 Prius
    Model:
    V


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

    13Plug Active Member

    Joined:
    Apr 7, 2008
    Messages:
    572
    Likes Received:
    92
    Your Vehicle Year:
    2013 Prius Plug-in
    Model:
    Plug-in Base
  5. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    Messages:
    2,406
    Likes Received:
    650
    Location:
    Trumbull, CT
    Your Vehicle Year:
    2004 Prius
    Model:
    N/A


    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

    Joined:
    Sep 5, 2009
    Messages:
    33
    Likes Received:
    8
    Location:
    California
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    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

    Joined:
    Mar 11, 2009
    Messages:
    775
    Likes Received:
    129
    Location:
    Owego, NY
    Your Vehicle Year:
    2006 Prius
    Model:
    II



    https://priuschat.com/shop/index.php?osCsid=2175dc3ff8aca307e7cb07f86adeab7b
  8. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    Messages:
    7,652
    Likes Received:
    874
    Location:
    United States
    Your Vehicle Year:
    2004 Prius
    Model:
    N/A
    The engine can destroy itself pretty quickly. Take it to a dealer.
  9. Tamim

    Tamim Slayer of Nug

    Joined:
    Sep 5, 2009
    Messages:
    33
    Likes Received:
    8
    Location:
    California
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    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

    Joined:
    Mar 8, 2008
    Messages:
    13,193
    Likes Received:
    3,152
    Location:
    Green Valley, AZ
    Your Vehicle Year:
    2007 Prius
    Model:
    N/A
    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

    Joined:
    Sep 5, 2009
    Messages:
    33
    Likes Received:
    8
    Location:
    California
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    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

    Joined:
    Jul 24, 2006
    Messages:
    4,139
    Likes Received:
    583
    Location:
    Edmonton Alberta
    Your Vehicle Year:
    2012 Prius
    Model:
    N/A
    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

    Joined:
    Sep 5, 2009
    Messages:
    33
    Likes Received:
    8
    Location:
    California
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    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

    Joined:
    Mar 8, 2008
    Messages:
    13,193
    Likes Received:
    3,152
    Location:
    Green Valley, AZ
    Your Vehicle Year:
    2007 Prius
    Model:
    N/A
    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.
Similar Threads: check engine
Forum Title Date
Gen II Prius Care, Maintenance and Troubleshooting Check Engine Light/Air Mass Sensor Repair Decision Sep 4, 2014
Gen II Prius Technical Discussion VCS, Red Exclamation, Yellow Exclamation, Check Engine Lights all suddenly turned on Aug 31, 2014
Generation 1 Prius Discussion 2002 - Suddenly get P1430 code w/Check Engine Light Aug 9, 2014
Prius c Care, Maintenance and Troubleshooting Check Engine Light (CEL) P2420 Jul 19, 2014
Gen II Prius Care, Maintenance and Troubleshooting Red Triangle check engine (PA080 Over Temperature)? Jul 15, 2014