Need help with 2004 Express MAF ground
December 2nd, 2019, 3:15 PM
#1
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Need help with 2004 Express MAF ground
I am trying to trace the ground(s) of the MAF to it's/their termination, but I do not have a wiring diagram to go by. I have looked and asked, to no avail. Could someone please help lead me to where I should look for a broken, damaged, or disconnected ground, so that I can hopefully turn off my check engine light?
Thanks in advance and cheers!
Thanks in advance and cheers!
December 2nd, 2019, 5:44 PM
#3
Diagrams @ gmupfitter.com
December 2nd, 2019, 5:59 PM
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I'm getting P0101 and P0102 codes. Going to check the frequency on the ground terminal when I get some assistance this evening, but so far, everything checks out that the MAF looks to be good.
Update - So, yes. In checking the Hz coming off the black wire (term. 5), I get roughly 3.0-3.1 kHz at idle, and the frequency increases and decreases mostly smoothly with the engine's RPMs. So, if the lit I've been following is accurate, I'm looking for a poor ground somewhere.
Update - So, yes. In checking the Hz coming off the black wire (term. 5), I get roughly 3.0-3.1 kHz at idle, and the frequency increases and decreases mostly smoothly with the engine's RPMs. So, if the lit I've been following is accurate, I'm looking for a poor ground somewhere.
Last edited by CharlzB.; December 2nd, 2019 at 7:34 PM.
December 2nd, 2019, 8:59 PM
#5
What did you use for ground reference when you probed the signal frequency?
Ground is ground. There should not be any oscillation there.
Also you need to look at the other causes for the code.
https://www.obd-codes.com/p0101
https://www.obd-codes.com/p0102
Such as:
- Dirty or contaminated mass air flow sensor
- Intake air leaks
- etc...
Did you look on gmupfitter yet?
You can also find schematics on http://www.bbbind.com/tsb-wiring-diagrams-database/
If you want diagrams, you need to tell us what engine you have.
Ground is ground. There should not be any oscillation there.
Also you need to look at the other causes for the code.
https://www.obd-codes.com/p0101
https://www.obd-codes.com/p0102
Such as:
- Dirty or contaminated mass air flow sensor
- Intake air leaks
- etc...
Did you look on gmupfitter yet?
You can also find schematics on http://www.bbbind.com/tsb-wiring-diagrams-database/
If you want diagrams, you need to tell us what engine you have.
December 3rd, 2019, 8:12 AM
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I used the negative battery terminal to reference the frequency coming from the MAF connector. This van has the 4.3L engine.
I did read that it's possible that an overoiled air filter could have contaminated the MAF sensor. Long story short, this van did have a K&N filter in it when I bought it, so that's a possibility, as the Hz #s were a bit low compared to what I was told to expect. So, I'll try some MAF cleaner first, then re-test and see what the numbers become.
Thanks everyone for your replies and insight. All is very much appreciated!
I did read that it's possible that an overoiled air filter could have contaminated the MAF sensor. Long story short, this van did have a K&N filter in it when I bought it, so that's a possibility, as the Hz #s were a bit low compared to what I was told to expect. So, I'll try some MAF cleaner first, then re-test and see what the numbers become.
Thanks everyone for your replies and insight. All is very much appreciated!
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