CEL + p1121 & p1150 codes pulled

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by HeatherW785, Aug 8, 2012.

  1. HeatherW785

    HeatherW785 New Member

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    Hello,

    My CEL came on a few weeks ago and went off after a day - this happened several times until it recently stayed on. I took it to a shop today and they pulled the codes p1121 and p1150 and told me it was likely something to do with the gas pedal and something to do with it wearing out over time (used a LOT of technical terms I've never heard before) which would be really expensive to fix. They still haven't gotten back to me with the official diagnosis, and everything I'm reading online says the p1121 code is related to the coolant flow control valve, which the shop did not mention at all. I didn't find much on the p1150 code ... can someone help with what these codes actually mean?

    Thank you - any help is greatly appreciated!
     
    #1 HeatherW785, Aug 8, 2012
  2. gmcneil05

    gmcneil05 Member

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    I would not let them touch the gas peddle if the car drives fine. Both those codes are for the coolant storage tank. Nothing to do with the gas peddle.
     
    #2 gmcneil05, Aug 8, 2012
  3. jdenenberg

    jdenenberg EE Professor

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    P1121 in a Prius is an indication that the coolant recovery tank valve is sticking. This is often due to air in the engine coolant system. Look to see if the coolant level is low and top it off if so. The coolant acts as a lubricant for that valve.

    P1150 is an out of temp range indication for the coolant recovery tank (AKA Thermos)

    JeffD
     
    #3 jdenenberg, Aug 8, 2012
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    DTC P1121 means that the engine coolant flow control valve is not working correctly.
     
    #4 Patrick Wong, Aug 8, 2012
  5. HeatherW785

    HeatherW785 New Member

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    Thank you for all of the responses.. I just picked up the car and they pulled 6 codes that were stored, and said they were unable to connect the dots on them. The car still drives fine for the most part - feels like it tugs a bit when I hit the gas pedal (barely touching it) but they weren't able to find anything wrong with it. He cleared the light and when I turned the car back on the CEL came on again. He cleared the CEL again, and had me drive it while he read the codes and he said he thought it has to be something with the throttle - the TP and Relative TP were running within 50% of each other (which he said is normal). But we shut the car off/turned on again and on the 3rd trip the CEL came back on.

    My car is a 2009 with only 55,000 miles on it. All routine maintenance has been done and it's well cared for. I have an appointment to take the car back in next week, but I'd like to see if I can get any more ideas in the mean time. Any thoughts?

    Codes pulled and info they gave on my paperwork:
    P1121 - Accelerator position sensor
    P1150 - Air fuel sensor
    U0293 - Generic
    C0302 - Generic
    P0842 - Generic
    U0100 - Generic
     
    #5 HeatherW785, Aug 8, 2012
  6. jdenenberg

    jdenenberg EE Professor

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    Again, P1121 in a Toyota has NOTHING to do with the throttle (it does on some other cars) and P1150 is a temperature sensor. Check the voltage of your 12v battery in the morning with the car still off, it may be low (a common Prius problem). Get to a shop that is familiar with a Prius. Where are you located?

    JeffD
     
    #6 jdenenberg, Aug 8, 2012
  7. HeatherW785

    HeatherW785 New Member

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    I'm in Santa Cruz, CA. How do I check he 12v battery? Is there a gauge I can grab at a nearby Autozone?

    Thanks again for all of your help!
    Heather
     
    #7 HeatherW785, Aug 8, 2012
  8. jdenenberg

    jdenenberg EE Professor

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    #8 jdenenberg, Aug 8, 2012
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  9. Avi's Advanced Automotive

    Avi's Advanced Automotive Independent hybrid repair shop

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    #9 Avi's Advanced Automotive, Aug 10, 2012
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