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absolute throttle position B at 55 percent

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sergbot, Jun 15, 2022.

  1. sergbot

    sergbot Junior Member

    Joined:
    Jan 19, 2021
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    Location:
    Hawaii
    Vehicle:
    2009 Prius
    Model:
    N/A
    [​IMG]

    The car seems to run okay when driving it around, but if left idling, it seems to not make enough power from the ice to charge the battery. Cyl 3 starts misfiring, and it charges super slowly.

    after replacing the fuel injectors, spark plugs, coil packs, and o2 sensors, im taking a look at the throttle body.

    I can take off the pcv hose to make a vacuum leak past the throttle body and the car works fine. except the 5000 rpm idle lol.

    it does seem like the the engine runs rich, and doesnt suck in enough air when idling. this issue would make sense if the throttlebody isnt opening enough.
    So what does this absolute throttle position thing mean? is that the exact actual throttle plate position? because is thats the case, then theres something wrong because my throttle plate isnt open half way.
    My throttle plate makes a hissing sound and it's almost closed.
     
    #1 sergbot, Jun 15, 2022
  2. ChapmanF

    ChapmanF Senior Member

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    Mar 30, 2008
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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    It looks like this app might be using different names for those PIDs than the names they have in a Techstream data list, which might add to the confusion a little. I don't have a Techstream Gen 2 data list to look at right now to see exactly which items it shows and what it calls them.

    The signals that tell the ECM how open the throttle is are two separate sensor voltages for redundancy. Graphed against the actual throttle opening, they have similar slopes but different intercepts.

    This drawing is from Gen 3, but I think the design of this part was pretty similar in Gen 2. It's possible some of the exact voltage details changed; better to look those up in the Gen 2 manual.

    vvv Gen 3 Gen 3 Gen 3 vvv
    [​IMG]
    ^^^ Gen 3 Gen 3 Gen 3 ^^^
     
    #2 ChapmanF, Jun 15, 2022
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