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Check engine light on

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sc1988, Jul 27, 2016.

  1. sc1988

    sc1988 Junior Member

    Joined:
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    Vehicle:
    2008 Prius
    Greetings all,

    Wondering if I can get some advice. This morning while driving my 2008 ( about 90,000 miles) the check engine light came on. When I got home used the mini cable + tech stream (thank you prius chat for recommending this reader!!!:)) and got the following codes:

    Engine ECU C1241 (low bat positive voltage or higher than normal Bat positive voltage)
    ABS ECU P1121 (throttle pedal position sensor stuck/ or coolant flow control valve position sensor stuck)
    Air conditioning B1421 (Solar Sensor circuit passenger side)

    Like to hear what you all think. My optima battery is about 5 years old and probably needs to be changed.
    The car ran well for the last 15 mins getting home after the check engine light.

    I have to go to a meeting for the rest of the afternoon so I couldn't check it out further for today.

    Thanks in advance for your help,

    Seth
     
    #1 sc1988, Jul 27, 2016
  2. JC91006

    JC91006 Senior Member

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    II
    The check engine light is from P1121, need to change the coolant valve. That won't affect the driving of the car, you won't break down.

    You should change the battery though. 5 Years is about a good time
     
    #2 JC91006, Jul 27, 2016
  3. andrewclaus

    andrewclaus Active Member

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    What the big dog said.
     
    #3 andrewclaus, Jul 27, 2016
  4. sc1988

    sc1988 Junior Member

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    Vehicle:
    2008 Prius
    Thanks guys!
    Sorry didn't get back sooner, I have been busy changing the control valve. It was stuck when I looked inside the old one!

    Since I am tinkering with the coolant system, might as well change the water pump, thermostat, and hoses while I have everything open.

    I'm gonna start a new thread for the 12 volt battery for I have a few questions for the group.

    Now if it will only stop raining here long enough I might get it done today

    Cheers!

    Seth
     
    #4 sc1988, Jul 29, 2016
  5. andrewclaus

    andrewclaus Active Member

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    You might think about changing the inverter coolant, too, since you're messing with it. It's nearly time and it easier to bleed than the engine. (I assume you know to run the CHRS and use the radiator bleed valve when you refill the engine coolant.) Good luck with the project.
     
    #5 andrewclaus, Jul 29, 2016
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I believe the hoses do not require replacement with 90K miles on the odometer. My 2004 has 222K miles logged and the hoses are still pliable.
     
    #6 Patrick Wong, Jul 29, 2016
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