MAF LS2 pink wire
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Racer
Joined: Apr 2015
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MAF LS2 pink wire
I am having an issue, long story short, I swapped my oem ls2 eninge back into my 2006 corvette. When i cranked it, it could barely idle. So i hooked up VCM scanner to it and it shows MAF state: failed, and i'm not getting any Hz readings. I checked the pin out I get the 4.8v on pin E and B, but I'm not getting any voltage at all on the pink wire, D. Is the pink wire , ignition voltage, supposed to be a constant 12v with the ignition on? Thanks!
Thread Starter
Racer
Joined: Apr 2015
Posts: 278
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I was referencing the top diagram as I'm pretty sure its the LS2 one,bc it matches my connector wiring. Is the bottom one for an LS3 card style MAF? I'm asking if the Ignition voltage is supposed to be a constant 12v or is it variable according to whats needed to heat the resistors in the MAF?
Last edited by BrownVette; Jul 18, 2018 at 08:32 PM.
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
C5 owner here !!...Yes, you should be getting 12V on the pink wire with KOEO....5 v ref. on the yellow (MAF)...just 3 wires for MAF you just have to worry about...how did you check the power wire ??....pink to body ground or pink to the black/white ground ??...I've helped a few members with MAF issues....your scanner will read Hz output ???...if still no power check the fuse or maybe you have an open...in that case you will have to break down the harness in sections and divide and conquer !!...I have a few a few tools to find shorts and opens...just picked up a signal generator ( GTC FF310 short and open circuit finder) a few weeks ago...works GREAT !!...P.S. Try unplugging the MAF and let it run on speed density (MAP).....see if it runs better !!....I've enclosed 3 pics of power, 5 volt ref. and ground !!
Last edited by C5 Diag; Jul 19, 2018 at 08:52 AM.
Thread Starter
Racer
Joined: Apr 2015
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Likes: 6
Thank you so much for the pictures! I am using the HPtuners VCM scanner and added the MAF (Hz) channel so I could log it. I am not getting 12v to the maf whatsoever. I am testing pink to ground and getting 0. The other reference signals I get are good to go, 4.8v on both, which are maf signal and iat signal. I can't unplug it because the pcm needs the IAT part of the MAF. My LS2 has the MAF and IAT integrated into one piece. I have searched and searched for schematics on which fuse the maf is run to. From what I gather it runs to a relay, which I've already swapped with another to check it. Doesn't make sense, its a 5 wire MAF, the ground and other 2 signal wires are good...but one wire has 0v....weird. I'm just trying to avoid cutting open the harness and untapping the parts I've tapped up already lol .Thanks again for your help!
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,490
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From: Cape Coral, Florida
Thank you so much for the pictures! I am using the HPtuners VCM scanner and added the MAF (Hz) channel so I could log it. I am not getting 12v to the maf whatsoever. I am testing pink to ground and getting 0. The other reference signals I get are good to go, 4.8v on both, which are maf signal and iat signal. I can't unplug it because the pcm needs the IAT part of the MAF. My LS2 has the MAF and IAT integrated into one piece. I have searched and searched for schematics on which fuse the maf is run to. From what I gather it runs to a relay, which I've already swapped with another to check it. Doesn't make sense, its a 5 wire MAF, the ground and other 2 signal wires are good...but one wire has 0v....weird. I'm just trying to avoid cutting open the harness and untapping the parts I've tapped up already lol .Thanks again for your help!
Last edited by C5 Diag; Jul 19, 2018 at 11:52 AM.
Thread Starter
Racer
Joined: Apr 2015
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Are you using "body ground" or the MAF "ground" to check ??....if you used the MAF ground you may have a ground wire that is open (black/white G106)... I looked at your wiring diagram and yes, your wiring is different from mine and goes through Emission fuse 14...check the load feed side of that fuse E10) and see if you have power there...if you do you have an open in that wire somewhere...that is the ONLY way to find the open is to work back from the MAF...use a 12 volt test light to pierce the wire (connected to battery negative) and when you're done cover the small hole with liquid electrical tape !!...to get FREE wiring diagrams go to bbbind.com...fill out the info... put your company in that box .....and hit enter and you're in !!...I use it when I'm diagnosing other cars !!...look at page 4 of the wiring diagram enclosed !!
Last edited by BrownVette; Jul 19, 2018 at 08:48 PM.
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Thread Starter
Racer
Joined: Apr 2015
Posts: 278
Likes: 6
Are you using "body ground" or the MAF "ground" to check ??....if you used the MAF ground you may have a ground wire that is open (black/white G106)... I looked at your wiring diagram and yes, your wiring is different from mine and goes through Emission fuse 14...check the load feed side of that fuse E10) and see if you have power there...if you do you have an open in that wire somewhere...that is the ONLY way to find the open is to work back from the MAF...use a 12 volt test light to pierce the wire (connected to battery negative) and when you're done cover the small hole with liquid electrical tape !!...to get FREE wiring diagrams go to bbbind.com...fill out the info... put your company in that box .....and hit enter and you're in !!...I use it when I'm diagnosing other cars !!...look at page 4 of the wiring diagram enclosed !!
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
I have not checked Emission fuse 14, in fact the emission stuff isn't plugged in because I wanted to fire it up prior to buttoning it up just to make sure everything ran correctly. I'll check fuse 14 in the morning, Im working night shift right now, I apologize for the delay in response. Thanks again for your help, I sincerely appreciate it, especially the PDF! Oh I had my multimeter stuck in the ground terminal of the battery when I was testing for 12v on the MAF. Then i swapped to power terminal of battery and checked the ground and got -12.7V so ground is good, and I went back and visually checked them.
Last edited by C5 Diag; Jul 19, 2018 at 09:43 PM.
Thread Starter
Racer
Joined: Apr 2015
Posts: 278
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That is correct black lead was on ground terminal of battery, red was on pink wire of MAF, no voltage. 12 hours on night shift stinkssssss lol. Well my MAF isn't reading bc i'm not getting any supply power to it, so my scanner shows no Hz, and maf state = failed. Map sensor works and so does everything else...kinda weird, the harness does run behind the block maybe somehow the moon and north star aligned and the pink wire got pinched/broken. I'll def check fuse 14, thanks again, the schematics/diagrams seriously helped!
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,490
Likes: 3,999
From: Cape Coral, Florida
That is correct black lead was on ground terminal of battery, red was on pink wire of MAF, no voltage. 12 hours on night shift stinkssssss lol. Well my MAF isn't reading bc i'm not getting any supply power to it, so my scanner shows no Hz, and maf state = failed. Map sensor works and so does everything else...kinda weird, the harness does run behind the block maybe somehow the moon and north star aligned and the pink wire got pinched/broken. I'll def check fuse 14, thanks again, the schematics/diagrams seriously helped!
Thread Starter
Racer
Joined: Apr 2015
Posts: 278
Likes: 6
I shall! Well just to update I got it fixed! Lol I checked fuse 14, and it wasn't blown....in fact it wasn't even there!! Some how some way it was removed, so I popped a spare fuse in and boom, she lives!! Thanks again for all your help, I really really appreciate it.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,490
Likes: 3,999
From: Cape Coral, Florida
i shall! Well just to update i got it fixed! Lol i checked fuse 14, and it wasn't blown....in fact it wasn't even there!! Some how some way it was removed, so i popped a spare fuse in and boom, she lives!! Thanks again for all your help, i really really appreciate it.