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DTC P1121 (coolant flow control valve psoition sensor stuck) went away

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by exstudent, Jan 8, 2014.

  1. exstudent

    exstudent Senior Member

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    Hi All.

    The CEL came on, but went away a few minutes later. When I got home and connected an OBD2 scanner, the DTC code was P1121 (Coolant Flow Control Valve Position Sensor Stuck). There is a Toyota Service Bulletin about this code, that many of you already know about.

    Both, drivability and engine noises seemed to be the same, before, during, and after the CEL came on.

    The Prius in question is a 2007 with 121,000 miles on it.

    Has this happened to any of you too? Should I just plan to change this valve some time soon? What could happen if I don't change it soon enough?
     
    #1 exstudent, Jan 8, 2014
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, you should change the valve at a convenient time. As you've noticed, the failure of the valve does not impact power train performance. This is solely associated with the coolant heat recovery system with regards to speeding up engine warmup.

    The valve failure might impact your cabin heater's performance.
     
    #2 Patrick Wong, Jan 8, 2014
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