code PO505; Idle Air Control System

Discussion in '100-Series Cruisers' started by DMX84, Jun 23, 2006.

  1. DMX84

    DMX84

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    What do I do to fix this? Any information would be appreciated.
    DMX
  2. DMX84

    DMX84

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    ^Bump
  3. hoser

    hoser SILVER Star

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    Just from what my reference material says:

    PO505: Idle speed continues to vary greatly from target speed.

    If no other code than PO505, then check air induction system.
    If okay, then check your electric throttle control system (ETCS).

    ETCS is composed of the throttle motor to operate the throttle valve, the magnetic clutch to connect the throttle motor with the throttle valve, the throttle position sensor to detect the opening angle of the throttle valve, the accelerator pedal position sensor to detect the accelerator pedal position, the ECM to control the ETCS and the one valve type throttle body.
    The ECM controls the throttle motor to make the throttle valve opening angle properly for the target idle speed.
  4. LEXUSBEN

    LEXUSBEN

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    Location:
    South Denver
    First thing I would try is cleaning the throttle body and then clearing the code/ecu learned memory. Have had them in the past gum up enought that motor cannot move throttle plate where ecu wants it because it is too dirty and that will set the 505 code. Start there and see if code reoccurs. Usually you can clean the t/b on the car too with a little brush and carb cleaner. Just make sure to keep the carb cleaner out of the sensors and motor.

    ben
  5. DMX84

    DMX84

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    Thanks Hoser & LexsusBen
    Here is a not too old picture of my TB. I’ve been reluctant to clean it because on my VR4 it kills the O rings in the TB. Also, I’m not sure if you can just reach in and crank open the TB plate (on the VR4 you just open the throttle) but on the Cruiser it is motor controlled, is it ok to just manually open it? And you mean not to get the cleaner on the TB motor, correct?
    I’ll probably get to this tomorrow.
    Thanks again
    Dean
    2 029.jpg
  6. LEXUSBEN

    LEXUSBEN

    Messages:
    214
    Location:
    South Denver
    Yes it is ok to manually open the throttle plate, just make sure the key is off so you don't set any weird codes.

    Best way is to use a rag and soak it with carb cleaner and scrub away, that way its not flowing everywhere. There are not really any o-rings that are going to get screwed up - only the sensors, they however are above the throttle shaft so if you do it in the car its pretty hard to screw them up. Take the throttle body off and then you can roll it around and the carb cleaner will find its way into the sensor/motor - BAD. If the carbon/junk is hard you can soften it up with carb cleaner and then scrub it with stiff little brush.

    I don't know if you have a code reader/clearer or not but with the key off if you pull the efi fuse (i think its a 20 or 25 amp) in the underhood j/b after about a minute the ecu memory will clear.

    ben
  7. DMX84

    DMX84

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    Got her all cleaned up and reset the ECU using my code reader. I’ll report back as soon as I find anything out. But no news is good news!
    Thanks!
    DMX
  8. e9999

    e9999 You want to do what...? Moderator

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    results?
  9. DMX84

    DMX84

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    I cleaned the TB& the results have been very good. No codes. If you remember, I had an incidence where I put it into reverse and it stalled the car (after driving 20 miles to work).
    I’m thinking it was all related the TB. But all is good now. Thinks to Ben for the suggestion!
    DMX
  10. e9999

    e9999 You want to do what...? Moderator

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    good to hear, in the FAQ!
  11. Interesting. I should go and inspect my TB for buildup. Ive been noticing a slight stutter when i start the motor cold. I wonder if buildup might have something to do with this.

    forgot to post back, took me a year to get around to it...but when the stalling started to come about frequently I finally cleaned it, no more problems for several months now.
    Last edited: Aug 2, 2008

  12. osomoso

    osomoso

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    4
    Well, this simplified everything. Glad I remembered to come here for tech advice. D

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