Code 157 maf

Discussion in '94-95 5.0 - Specific' started by 1slow50, Feb 8, 2014.

  1. 1slow50

    1slow50 New Member

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    95 gt, cai, shortys n o/r x pipe. I have replaced the maf n still getting the code 157. Could it b a wiring problem? How would I go about checking that?

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  2. ryclef331

    ryclef331 Well-Known Member

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    how long was the CAI on the car before you got the code? If it was a recent thing and the code popped up shortly after, that may be an issue. Check the harness, connector, etc. for cracks, chaffing, shorted out wires. Start with that and report back.
     
  3. 1slow50

    1slow50 New Member

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    I looked over the wires that I could see without digging in the wheel well n stuff. Everything looks good.

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  4. CC'S95GT

    CC'S95GT Legend

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    when was the last time the MAF was cleaned.
    CAI's with filters that get oiled has a tendancy to deposit oil on the MAF and give bad readings to the computer.
     
  5. 1slow50

    1slow50 New Member

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    I replaced the maf already, I was having the same problem b4 I changed it cuz I thought it was bad. I cleared the codes after I replaced it n came back. How do I test it with a mulimeter? Which wires do I test n what should it read?

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  6. CC'S95GT

    CC'S95GT Legend

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    Not sure how to test the MAF.
    I do know they are heated.
    the wiring diagram in the back of your Haynes/Chilton manual might help out there.
     
  7. Addermk2

    Addermk2 Well-Known Member

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    [TABLE="width: 87%, align: center"]
    [TR]
    [TD]
    157
    [/TD]
    [TD]
    (R,M)​
    [/TD]
    [TD]
    Mass Air Flow signal is/was low or grounded – MAF
    [/TD]
    [/TR]
    [/TABLE]


    [​IMG]


    With a DVOM (multi-meter) check continuity from pins 9(TAN/LT BLU) and 50(LT BLU/RED) to their corresponding ends on the maf harness. also, with the main ECU and maf plugs disconnected, check for continuity to ground.
     
  8. 1slow50

    1slow50 New Member

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    now where it says control module, in fact that is the plug goin to the ecu right?? and test pin 9, 50?
     
  9. Addermk2

    Addermk2 Well-Known Member

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    yes..

    Did I not explain it enough? Would you like me to go into greater detail? (not trying to be a dick here either... serious question)
     
  10. 1slow50

    1slow50 New Member

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    Yea if u want, that would be great, I'm a back yard mechanic in training lol. I've really never messed wit the electrical system too much. That's y I might ask sum dumb ass ?s I wanna make sure I'm doin it right

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  11. 1slow50

    1slow50 New Member

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    so i tested the voltage at the maf plug wit key on engine off and it was reading 12 volts, so i went further back to the next plug the 1 that comes out of the fender and that tested -5.85. im guessing i have a real problem here. i unpluged the ecu n it has 3 rows of pins, i cant find a pic to show me what pins i should b testing for cont.
     
  12. 1slow50

    1slow50 New Member

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    i been trying to pull sum pics up of the ecu plug to find out which 1s are pin 50 n pin 9, do they go in order? the 1s i have seen go in order starting at the bottom @ #1 up to the top to #60. is that correct? just trying to make sure im checking the continuity in the right pins
     
  13. Addermk2

    Addermk2 Well-Known Member

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    There are numbers on the connector.
     
  14. 1slow50

    1slow50 New Member

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    I test #9 n it was good, the color of the wire changed from the ecu plug to the maf harness. Nothing on #50

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  15. 1slow50

    1slow50 New Member

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    i was able to get a reading from pin 9 but nothing on pin 50. so im trying to track the wire but the colors are throwing me off. its 1 color coming from the ecu plug and a diff color when it gets to the maf harness. when its running n i unplug maf it still runs, no change in idle, same thing when i unplug the iac. when i unplug the tps the idle changes but the rpm's wont hang. when everythings plugged in the it rev's up to 2300 pms n then bogges down n hangs. i have replaced almost everything but tps n iac.
     
  16. 1slow50

    1slow50 New Member

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    Am I gonna have to cut all the tape n wire loom away from all the wires to see where the problem is?

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  17. toyman

    toyman Active Member

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    I'm puzzled by the wire color change. That shouldn't be the case. Exactly what colors are you seeing at the MAF that you think are coming from the ECU (PCM). Pin 50 light blue red stripe to ?? and Pin 9 Tan with light blue stripe to ?? at the MAF connector.
     
  18. Addermk2

    Addermk2 Well-Known Member

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    I haven't really been following the thread, sorry. I'll update either tonight or tomorrow at some point.
     
  19. 1slow50

    1slow50 New Member

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    Ok so this green/orange wire is coming from pin #9
    [​IMG]


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  20. 1slow50

    1slow50 New Member

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    [​IMG]

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