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Vacuum Pump Off Fail on a 2001 Prius

Discussion in 'Generation 1 Prius Discussion' started by lueung, Nov 7, 2015.

  1. lueung

    lueung Junior Member

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    What does this part look like & where is it located? (I can't really seem to find anything for this in the service manual) What am I missing here?

    Below is a screenshot of codes & diagnostics (The gas cap, charcoal canister, lines & vsv front & rear solenoids have been checked). I've done smoke test and even swapped the above from a working 2003 Prius.

    Screenshot by Lightshot
     
    #1 lueung, Nov 7, 2015
    Last edited: Nov 7, 2015
  2. ChapmanF

    ChapmanF Senior Member

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    There isn't really a vacuum pump per se, but if you read up on your evap system in the New Car Features Manual you'll pick up on how it operates.

    The components you say you've checked are pretty much the ones you would want to check ... were you doing the exact checks suggested for those codes in Volume 1?

    -Chap
     
    #2 ChapmanF, Nov 7, 2015
  3. lueung

    lueung Junior Member

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    Yes. I also did a smoke test & even swapped it from a 2003 Prius so this has me stumped. There must be something I've overlooked or missing.
     
    #3 lueung, Nov 7, 2015
  4. ChapmanF

    ChapmanF Senior Member

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    Maybe ... so, help us out some. What were the voltages you got in steps 10 and 11 on page DI-90, step 24 on DI-95? What did the valves do in steps 13, 15, 17, 19, 21, 22?

    -Chap
     
    #4 ChapmanF, Nov 7, 2015
  5. lueung

    lueung Junior Member

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    It has probably been 6 months since I did the test, but if memory serves the test voltages were within specs slightly below 5volts. The solenoids clicks and no apparent obstructions.

    With the code combination it's has to be a pretty severe leak. I'm going to go over everything again when the weather is good. Would be really nice to have a car lift, it would definitely make life so much easier. LoL

    One terminology that is a little confusing is the, "Vacuum Pump Off: Fail -124.022 kPa."
     
    #5 lueung, Nov 8, 2015
    Last edited: Nov 8, 2015
  6. MDNHW11

    MDNHW11 Junior Member

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    Remove the fuel filler neck and check the top for rust perforation. It is a very easy filler neck to remove.
     
    #6 MDNHW11, Nov 8, 2015
  7. lueung

    lueung Junior Member

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    Would you happen to have the instructions or pics for the easiest way to remove the filler neck?
     
    #7 lueung, Nov 9, 2015
  8. MDNHW11

    MDNHW11 Junior Member

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    It is the pipe that you put the fuel pump nozzle in.

    My calling it "easy" is a comparison to other vehicles, and assumes that you are comfortable jacking and properly supporting the vehicle on jack stands.

    Just follow the pipe and disconnect it from the vehicle and hoses it connects to.
     
    #8 MDNHW11, Nov 9, 2015
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