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05 with P1121 and P1116 codes- VSC/ABS/Brake/(!) on Dash

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Moist Mist, Dec 17, 2020.

  1. Moist Mist

    Moist Mist New Member

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    05 Prius with 235k miles, I just drove 35 miles on the highway with no problems. When I restarted my car after a quick stop, the VSC, ABS, and brake light were all on my dashboard. I borrowed an OBDII scanner and got the P1121 and P1116 codes. Car seems to start and turn off just fine, no apparent issues with the battery, 12V was replaced last year. ABS and VSC are not working. P1121 is for the coolant control valve, could that cause problems with the ABS and VSC? I'm an entry level DIY, the Prius is in a parking lot 40 miles from my house, any help is greatly appreciated!
     
    #1 Moist Mist, Dec 17, 2020
  2. Moist Mist

    Moist Mist New Member

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    235,000 miles and I just drove part of the way to work, stopped at the store for 15 minutes, then when I restarted it, the dashboard lit up. Car still starts and accelerates fine, brakes were not working normally, which is why the ABS light was on, I assume. I did manage to get my car the 5 miles to work, but for safety reasons, I left it there, 40 miles from my home, and got a ride. I borrowed an OBDII scanner and got the P1121 and P1116 code, everything I have found suggest I need to replace the coolant control valve, is this the fix? Could a bad coolant valve cause the issues with my brakes and traction control? I need your knowledge!!!
     
    #2 Moist Mist, Dec 19, 2020
  3. bisco

    bisco cookie crumbler

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    you might need a prius aware scanner, like tech stream
     
    #3 bisco, Dec 19, 2020
  4. Moist Mist

    Moist Mist New Member

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    I genuinely don't know, how is that different than other OBD readers?
     
    #4 Moist Mist, Dec 19, 2020
  5. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    The OBD2 scanner you're using may not be fully toyota hybrid compatible. Best to try other scanners, most auto part chain stores offer a free scan, and even the same stores within a chain may offer different scanners, which may or not work. Try them all.

    The most affordable and 'best in class' would be a 'mini-vci' cable ($20) with a copy of techstream (dealership technician diagnostic software) installed on a windows device (emulated or otherwise). Others have found relief using a simple OBD2 bluetooth adapter and an App like Dr Prius or Torque.

    Here is the workup for DTC P1116 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/2054m/cip1116.pdf

    Here is the workup for DTC P1121 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/2054m/cip1121a.pdf
     
    #5 SFO, Dec 19, 2020
  6. mr_guy_mann

    mr_guy_mann Senior Member

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    When you say "the brakes were not working normally", what do you mean- aside from the warning lights that is? Unusual sound or pedal feel, car barely slows down, what?

    That said, if you do not feel confident wirh brake operation, then absolutely do not drive it. You may need to have it towed to someplace to have it diagnosed.

    The OBD2 scanner you used pulled codes for the engine computer. P1121 is for the "3-way coolant valve" that directs engine coolant into or out of the coolant heat storage tank (thermos bottle) and the heater. Very common fault on a Gen2 prius. P1116 is for a temperature sensor at the storage tank. I would not expect either to affect the braking system.

    You need a "better" (enhanced) scantool that can talk to all the systems on a Prius- esp the ABS computer. Without that you/we would be guessing about what is wrong.

    Posted via the PriusChat mobile app.
     
    #6 mr_guy_mann, Dec 19, 2020
  7. Moist Mist

    Moist Mist New Member

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    The brakes work, it just take some pressure on the pedal to get them to engage, and when they do, it feels like I'm slamming on the brakes. I just ordered a new scanner, I'm guessing it'll be a while before it shows up with Christmas around the corner. I was confused with the codes I got and the issues I'm experiencing, which is why I'm here. I appreciate everybody's help, thank you all so much!
     
    #7 Moist Mist, Dec 19, 2020
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