P0108 gen4 Prius wiring diagram need

Discussion in 'Gen 4 Prius Main Forum' started by Kwm488, Apr 18, 2026 at 6:53 PM.

  1. Kwm488

    Kwm488 Junior Member

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    Hi
    I got P0108 code. I cleaned manifold and changed MAF sensor. But I still get this code. It will come out even I clear it. So annoying. My grange checked it, they guess the wire problem.

    where can I find the wiring diagrams please
     
    #1 Kwm488, Apr 18, 2026 at 6:53 PM
  2. ChapmanF

    ChapmanF Senior Member

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    #2 ChapmanF, Apr 18, 2026 at 8:55 PM
    Brian1954 likes this.
  3. Kwm488

    Kwm488 Junior Member

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    Hi
    I found wiring diagram. I replaced MAP sensor and checked MAF sensor wire (from plug to ECU) . All no problem.

    I guess maybe 12v battery or vacuum leak. Do anyone can give me some suggestions please ?
     
    #3 Kwm488, Apr 19, 2026 at 6:52 PM
    Last edited: Apr 20, 2026 at 1:37 AM
  4. Brian1954

    Brian1954 Senior Member

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    Code P0108 is for MAP ( Manifold Absolute Pressure), not for MAF (Mass Air Flow).
     
    #4 Brian1954, Apr 19, 2026 at 7:05 PM
    Last edited: Apr 19, 2026 at 10:38 PM
  5. Kwm488

    Kwm488 Junior Member

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    Thank you brain. I changed the word to MAP.
     
    #5 Kwm488, Apr 20, 2026 at 2:15 AM
  6. Brian1954

    Brian1954 Senior Member

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    Which sensor did you replace and the wiring checked? Was it the sensor that is visible on the top of the air box, or was it the sensor mounted into the intake manifold next to the throttle body?
     
    #6 Brian1954, Apr 20, 2026 at 8:55 AM
  7. Kwm488

    Kwm488 Junior Member

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    Hi
    I replace this MAP sensor. It is visible , mount into the intake manifold

    I uploaded a photo
     

    Attached Files:

    #7 Kwm488, Apr 20, 2026 at 1:13 PM
  8. Brian1954

    Brian1954 Senior Member

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    Yes, that is the MAP sensor.The location on a Gen 4 is different than on my Gen 3.

    What is the short term fuel trim (STFT) and long term fuel trim (LTFT) when the engine is idling?

    I am guessing that you have a vacuum leak. I would first check the small vacuum hose on the sensor. Find out were the other end of that vacuum hose connects to. Check both ends of the hose for any cracks that may have developed. Replace the vacuum hose if you see any cracks.
     
    #8 Brian1954, Apr 20, 2026 at 2:09 PM
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