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Old Oct 17, 2014 | 10:16 AM
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Default MAF questions

My 99 z28 has a code for maf sensor circuit low. I unplugged it and checked it with a multi meter and the black and yellow were had no power but the pink wire had 5v. Has anyone else had a similar issue. I went further down the wire with the same results. Any help is greatly appreciated!
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Old Oct 17, 2014 | 11:47 AM
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That probably how it should be, a power wire that reads 5v, a ground, and a wire that goes back to the computer with the MAF reading. You probably have a bad MAF or it just needs cleaned. Also stop pocking holes in your sensor wires with you multi meter you may damage the wires and even if taped your still risking moisture getting in and corroding the wire.
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Old Oct 18, 2014 | 05:12 PM
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A P0102 code is what you have.
The black(center) wire is ground, yellow wire is signal, and pink is power. The 5 volts you got is what you should be reading at the yellow signal wire, 12 volts at the pink power wire.

Check for and fix any vacuum leaks.
Check for proper grd through the blk wire.
Buy some MAF cleaner and clean it.

Last edited by 99Bluz28; Oct 19, 2014 at 02:05 PM. Reason: drinking and logic don't mix!
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Old Oct 18, 2014 | 08:49 PM
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ENG SEN fuse = ?
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Old Oct 19, 2014 | 01:00 AM
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He still has 5 volt power up to the MAFs.
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Old Oct 19, 2014 | 01:11 AM
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Should be 12V, not 5V.
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Old Oct 19, 2014 | 01:20 AM
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According to my gm service manual for a 99 camaro with LS1 engine 5 volt is what he should be reading up to the sensor. It's on page 1436 in volume 2.
FYI, power wire is 12 volt.

Last edited by 99Bluz28; Oct 19, 2014 at 02:11 PM. Reason: sober correction
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Old Oct 19, 2014 | 01:48 PM
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5V is not power, it's the PCM input's pullup level. The
MAF runs off 12V ENG SEN branch.
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Old Oct 19, 2014 | 02:12 PM
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Thanks for the correction; everybody.
Yes, drinking and logic don't mix well, it makes a lot more sense sober!
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Old Oct 19, 2014 | 02:22 PM
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Originally Posted by uptonls1
My 99 z28 has a code for maf sensor circuit low. I unplugged it and checked it with a multi meter and the black and yellow were had no power but the pink wire had 5v. Has anyone else had a similar issue. I went further down the wire with the same results. Any help is greatly appreciated!
I was speaking to this.
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Old Oct 19, 2014 | 06:03 PM
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That a problem then, the pink power should be 12 Volts.
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Old Oct 20, 2014 | 11:30 PM
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thanks for all the info guys!! it was the eng sens fuse. that fixed my lock up issue and my o2 sensor code also.
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