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Thread: 3 MAFs Dead or PCM ?

  1. 02-28-2021 #1
    metalmanimal
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    3 MAFs Dead or PCM ?

    I've been dialing in my VE table and went to enable MAF so I could start to tune my MAF curve. As soon as I enable my MAF, it no longer shows any Htz on the scanner and will not run in MAF fail mode at all. I reenabled SD mode and it will run but now the VE is out of tune again and runs poorly now. tried 2 different MAF sensors one from a good running vehicle and I still get no reading from the MAF. checked the wiring and12v ign. feed, 5v both on IAT and MAF signal. good low reference for IAT and ground.
    Anyone ever have a PCM fail in this way ? Its the only thing remaining. This is the last log before it went TU and my VE tuning file that was reading MAF frequency before it failed.
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  2. 02-28-2021 #2
    kevin87turbot
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    Post your tune that has the MAF mode enabled, along with a datalog, and I'll bet we can help you out.
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  3. 03-01-2021 #3
    metalmanimal
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    I haven't tried to run it in mixed mode yet, give it a try tomorrow. here is my Maf logging and mixed mode tune.

    Could it be because I have PE enabled at 0 to 1200 rpm 1.0 EQ to help out with the idle ? Could PE at idle be disabling the MAF ?
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    Last edited by metalmanimal; 03-01-2021 at 12:10 AM.
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  4. 03-01-2021 #4
    2xLS1
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    Quote Originally Posted by metalmanimal View Post
    I haven't tried to run it in mixed mode yet, give it a try tomorrow. here is my Maf logging and mixed mode tune.

    Could it be because I have PE enabled at 0 to 1200 rpm 1.0 EQ to help out with the idle ? Could PE at idle be disabling the MAF ?
    No. Have you checked the MAF power wires for 12V and ground?
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  5. 03-01-2021 #5
    metalmanimal
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    Yes 12v on pin d and good ground on C , checked signal wire and IAT wire to the PCM and have 5v on both. Even ran another jumper signal wire to rule that out as well.
    I'm stumped. It wont even run right anymore in SD mode now which doesn't make any sense. Starting to think its a PCM issue it was a EBAY Re Flash unit maybe it was out of a flood car or something. This would be the second PCM that has failed on me since I upgraded the MPVI2 hope its not my programmer either.
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  6. 03-01-2021 #6
    metalmanimal
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    2 short logs, I keep getting p0102 code but the MAF still has no frequency or volts. the MAF works just fine and shows Hz on my other vehicle. have 12v KOER good grounds Jumped wire straight to signal pin and still no MAF, even tried a new MAF connector.
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  7. 03-01-2021 #7
    2xLS1
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    When you check for 12V at the MAF are you referencing to the MAF ground wire or to another ground like - battery or engine block/head?
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  8. 03-01-2021 #8
    metalmanimal
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    Had a 12v, ground and signal wire jumped externally to eliminate the harness completely and still nothing. I noticed the CAM HI LO counts start to go all out of sync when the MAF is plugged in which I find even more bizarre.
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