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Check engine light p1121 and p1116 related?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by AshleyNK, Oct 13, 2014.

  1. AshleyNK

    AshleyNK New Member

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    Hi everyone,

    I've searched through a lot of threads here and I see that P1121 is a common issue. We pulled this code back in May on our 2004 w 165k miles. We took it to a mechanic who told us that since it was emissions-related the fix wasn't essential right away and wouldn't cause any damage. Since then, the code has gone on and off and we haven't experienced any problems driving. Today, we pulled the same code + 1116 which I read is a sensor. I know both of these have to do with the coolant control valve, but could it be one issue triggering both codes? How serious is the second code, p1116? We have to drive 1k miles over the next week and we just want to make sure it won't cause damage to the engine.

    Thanks for any help!
     
  2. JimN

    JimN Let the games begin!

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  3. AshleyNK

    AshleyNK New Member

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    Thank you! I think they have to be related (maybe valve caused sensor to break?). Everything I've read says you could probably ignore coolant control valve forever with no damage to the engine ... I just can't find much about leaving the sensor for now.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. Check the engine coolant level in the radiator as well as in the overflow container.
    2. Use Toyota Super Long Life Coolant if needed.
    3. Yes, if the engine coolant level is correct then you can ignore P1116 and P1121. However you need to keep an eye out for other DTC that might be logged.