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  1. ITGuy1024

    ITGuy1024 Junior Member

    Joined:
    Apr 25, 2010
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    Location:
    York, PA
    Vehicle:
    2006 Prius
    Model:
    II
    A few days ago my CEL came on and the code is P0505.
    The car is running normal, no sputtering, hesitation, rough idle or drop in mpg.

    Some things I want to check:
    Oil cap
    Cracked hoses
    Replace PCV valve?
    Clean throttle body?

    Any other ideas?
     
  2. jdenenberg

    jdenenberg EE Professor

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    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    P0505 indicates some problem with the electric idle system. I would check to make sure that the air cleaner is in place, check the hose(s) going to the PCV system and look for any other hoses that may be cracked or have come loose. If you can't find anything wrong, you may need to take it in for service.

    JeffD
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
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    Two
    DTC P0505 means that the engine ECU detects that the idle speed varies more than 200 RPM from the expected value, five times or more during a drive cycle.

    Yes, I would suggest that you clean the throttle body interior and throttle plate. Remove the air cleaner housing, then spray throttle body cleaner on a clean cloth and use the cloth to scrub off the dirt in the throttle body. Do not flood the intake manifold with throttle body cleaner.

    Check the PCV hoses for leaks. Check the oil cap and oil dipstick O-rings to make sure they are sealing. If your car has 100K miles or more then change the PCV valve. Make sure there are no leaks in the air induction system, especially below the throttle plate.

    If the above does not help the problem, then you may need to replace the throttle body assembly.
     
  4. ITGuy1024

    ITGuy1024 Junior Member

    Joined:
    Apr 25, 2010
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    Location:
    York, PA
    Vehicle:
    2006 Prius
    Model:
    II
    Oil and dip stick cap look to be ok.
     
  5. ITGuy1024

    ITGuy1024 Junior Member

    Joined:
    Apr 25, 2010
    78
    5
    0
    Location:
    York, PA
    Vehicle:
    2006 Prius
    Model:
    II
    Everything seems to be ok. The clamp that connects the air box to the throttle body was a little loose so I tightened that up while I cleaned the throttle body itself.
    The CEL was gone when I reconnected the sensor.

    I'll update to see if it's fixed or not.