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Thread: Gm lsa - maf sensor

  1. #1
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    Gm lsa - maf sensor

    Hi guys,

    I am in need of some help if you are able to assist!

    I have a stock GM LSA from a 2013 Cadillac CTSV which has been swapped into a classic car which we have nearly completed.

    I am running the GM MAF sensor GM Part#15865791 which I believe is the one most LSA swap-shops supply with their kits?

    However some forums are saying that the stock vehicle runs GM Part#23256991

    My question? Is there a setting in HP tuners that I need to switch or adjust as my new MAF is NOT being detected by the E67 ECM?

    Or could I have a faulty MAF from the box?


    Cheers!

  2. #2
    Tuning Addict 5FDP's Avatar
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    There is no setting to change from the MAF, like we can't really tell it what MAF it's running. We can change the max MAF hz value but that's not what we need here.

    The MAF airflow freq table would need to be adjusted if the MAF's are different styles.

    But if your MAF is not even working at all, you need to start there. Check power at the harness and such. If that is all good then the new sensor might be bad.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
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    Thanks for that...

    I have a new sensor on the way... and we have tested the power feeds etc and they look good.

    So if I am running the GM Part#15865791 and it should actually be GM Part#23256991, would I need to adjust the frequency table?

    How do I found out what actual MAF sensor the original E67 would have been tuned with?

    And if GM Part#15865791 is the wrong one and it needs a table change, is there a base table I can copy from another tune?

    Cheers
    Craig

  4. #4
    Tuning Addict 5FDP's Avatar
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    A 2013 CTS-V would have run the 23256991 sensor from the factory.

    The one you have installed was used on some of the earlier cars like the LS3 6.2 in the corvette/camaro and the 7.0, also the earlier supercharged 6.2's.

    So it was used in the S/C 6.2 but is the harness pins the same is the other question. You can find and compare a tune that ran that sensor to see if the MAF fail high FQ settings are any different.

    Other things to consider here is the size of the intake tube. If the intake you are running is different than the factory intake, you will have to tune the MAF for that. A different size intake tube will cause the sensor to read off compared to stock. For example all the high horsepower cars bump up to 4in or 5in intakes so the MAF will still have resolution, otherwise they'd max the sensor out in a 3.5in intake tube.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    Senior Tuner TheMechanic's Avatar
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    The slot style meter tends to sample a little better in blow through. If you are running a large housing in suck-through (4" or bigger) the slot style also gives a stable signal in a big housing, It is a newer design and a lot of the tuners like using them. they are also less susceptible to backwash issues.

  6. #6
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    Thanks all

    When I purchased the engine, the wrecker had cut the wires off to the MAF and the original MAF/intake tube was not included.

    I purchased another 4 inch intake assembly for what I thought was a CTSV and in fact it may have been an earlier CTSV version as it had the slot style MAF installed but only had 4 pins not 5 pins.

    So I removed the 4 pin card and purchased the GM Part#15865791 (5 pin slot style)

    It appear the 5 pin also has the IAT1 included within it?

    Where do you recommend I find a tune for this sensor?

    Cheers

  7. #7
    Tuning Addict blindsquirrel's Avatar
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    How are you verifying the correct pinout if you're unsure of what the sensor came from?

  8. #8
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    Quote Originally Posted by blindsquirrel View Post
    How are you verifying the correct pinout if you're unsure of what the sensor came from?
    The E67 ECM already had the pin outs (5 pin) So we purchased a new 5 pin plug. We also used a CTSV wiring diagrammatic to check.

  9. #9
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    Quote Originally Posted by Crackerbuzz View Post
    The E67 ECM already had the pin outs (5 pin) So we purchased a new 5 pin plug. We also used a CTSV wiring diagrammatic to check.

    As long as the schematics were from a 2009+ CTS-V, then your wiring should be correct.

    The earlier 2006 and 2007 CTS-V LS2 models used a "tube" style MAF Sensor - with different wiring.

  10. #10
    Tuning Addict blindsquirrel's Avatar
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    Doesn't know what application the MAF sensor is from to know which wiring diagram to look up, doesn't know what is meant by 'pinout'... this is going well.

  11. #11
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    Quote Originally Posted by Jon S. View Post
    As long as the schematics were from a 2009+ CTS-V, then your wiring should be correct.

    The earlier 2006 and 2007 CTS-V LS2 models used a "tube" style MAF Sensor - with different wiring.
    Haha yes we will eventually get there!

    I have been using a 2011 wiring diagram.

    I will fit the new unit and let you guys know what happens!


  12. #12
    Tuning Addict blindsquirrel's Avatar
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    If you pinned it anything other than this, you do not have a bad sensor, you have the wires in the wrong holes in the connector (this is what is meant by the term 'pinned'/'pinning'/'pinout'):
    screenshot.22-11-2020 02.29.47.png

    '11 CTS used 23256991, not the one you have. Just because the connector has 5 wires and looks like the same shape DOES NOT mean all the wires go in the same locations for all the different part numbers!

  13. #13
    It's been a while and this may not help but I used a card style with integrated iat and I had to swap the two signal wires then I found a tune on the repository that used the same maf and copy and pasted the maf and iat info for a starting point

  14. #14
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    Quote Originally Posted by blindsquirrel View Post
    If you pinned it anything other than this, you do not have a bad sensor, you have the wires in the wrong holes in the connector (this is what is meant by the term 'pinned'/'pinning'/'pinout'):
    screenshot.22-11-2020 02.29.47.png

    '11 CTS used 23256991, not the one you have. Just because the connector has 5 wires and looks like the same shape DOES NOT mean all the wires go in the same locations for all the different part numbers!
    Thanks... Mine is a 2013 CTSV. Which sensor would that have come with?

  15. #15
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    Quote Originally Posted by geneass View Post
    It's been a while and this may not help but I used a card style with integrated iat and I had to swap the two signal wires then I found a tune on the repository that used the same maf and copy and pasted the maf and iat info for a starting point
    Thanks!

  16. #16
    Tuning Addict blindsquirrel's Avatar
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    Quote Originally Posted by Crackerbuzz View Post
    Thanks... Mine is a 2013 CTSV. Which sensor would that have come with?
    23256991 - CADILLAC CTS 2009-2015

    The MAF pinout posted above is for the one you have, 15865791. Go to https://www.rockauto.com/, put a part number in the search box. On the results page click the part number and it will show you what applications use that number.

    http://www.gmpartsdirect.com/ is good as a reference too, some discontinued parts don't appear in the aftermarket lookups but can be found from dealer sources.

  17. #17
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    Quote Originally Posted by blindsquirrel View Post
    23256991 - CADILLAC CTS 2009-2015

    The MAF pinout posted above is for the one you have, 15865791. Go to https://www.rockauto.com/, put a part number in the search box. On the results page click the part number and it will show you what applications use that number.

    http://www.gmpartsdirect.com/ is good as a reference too, some discontinued parts don't appear in the aftermarket lookups but can be found from dealer sources.
    Nice, Cheers

  18. #18
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    2009 CTSV 6.2 supercharged, gm 23256991. The MAF is marked on the case (-) (+) (O) (I) (I) in that order.. Obviously Ground, 12+, what are the next 3?

  19. #19
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    Hi All,

    Finally got the MAF operational... I have started a new thread based on this.

    Thanks for all comments

    https://forum.hptuners.com/showthrea...ve-an-HPT-file
    Last edited by Crackerbuzz; 01-11-2021 at 06:47 AM.