How to test Mass Air Flow (MAF) Sensor (GM)

Today I show how to test an MAF on a 4.2-liter engine - GM
For the article, I wrote go here - hammondautollc.alberthammond.i...
Tools used:
DVOM - amzn.to/2s920wh or amzn.to/2r0zV6s
Back probes - amzn.to/2sIewA1
DSO - amzn.to/2sIAraj
Closely related MAF circuit trouble codes include:
⦁ P0100 Mass or Volume Air Flow "A" Circuit Malfunction
⦁ P0101 MAF Circuit Range/Performance
⦁ P0102 Mass or Volume Air Flow "A" Circuit Low Input
⦁ P0103 Mass or Volume Air Flow "A" Circuit High Input
⦁ P0104 Mass or Volume Air Flow "A" Circuit Intermittent
Note: other codes may be present if you have P0100 codes.
Symptoms may include
⦁ Malfunction indicator lamp MIL illumination - a.k.a. check engine light
⦁ Rough running engine
⦁ Black smoke from tail pipe
⦁ Stalling Engine hard start or stalling after it starts
⦁ Possible other driveability symptoms
Possible Causes
⦁ Dirty or contaminated mass air flow sensor
⦁ Failed MAF sensor Intake air leaks
⦁ MAF sensor electrical harness or wiring problem open, shorted, frayed, poor connection, etc.
⦁ Clogged catalytic converter on some models - GMC/Chevrolet mainly
What I do first is I check the electrical connections I make sure contacts are not spread open then I check the circuit for power, ground and 5 volt reference signal if you don't know how to do this here's a link that will show you how to check the circuit for your car troubleshootmyvehicle.com/ .
Then check for air leaks look at the tube between the MAF and the intake check the connections on that tube make sure they are snug. if I can't find any holes, tears or loose connections with a visual inspection or hear them when the car is running. Then I use a spray bottle with water. Start the car and spray around the intake the engine will sputter when the water finds a leak or better yet use a smoke machine if you don't have one then use cigar smoke if you smoke or know someone who does you'll have to get creative here rig up a small hose to the intake system make sure there's no gaps Light up a cigar and blow it in the intake system if there's any leaks you'll see them
And last step if all else falls check for a clogged catalytic converter.
Disclaimer:
Due to factors beyond the control of Hammond Auto LLC, it cannot guarantee against unauthorized modifications of this information or improper use of this information. Hammond Auto LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Hammond Auto LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of Hammond Auto LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not Hammond Auto LLC.

[@nightowl1654]

If I replaced the maf and p0100 goes on, what do I do?

[@hammondautollc7809]

Well first off a P0100 code means that there is a problem with the MAF circuit which could be a bad or dirty MAF or there is unmetered air getting in some where after the MAF.
What I do first is I check the electrical connections I make sure contacts are not spread open then I check the circuit for power, ground and 5 volt reference signal if you don't know how to do this here's a link that will show you how to check the circuit for your car troubleshootmyvehicle.com/ .
Then check for air leaks look at the tube between the MAF and the intake check the connections on that tube make sure they are snug. if I can't find any holes, tears or loose connections with a visual inspection or hear them when the car is running. Then I use a spray bottle with water. Start the car and spray around the intake the engine will sputter when the water finds a leak or better yet use a smoke machine if you don't have one then use cigar smoke if you smoke or know someone who does you'll have to get creative here rig up a small hose to the intake system make sure there's no gaps Light up a cigar and blow it in the intake system if there's any leaks you'll see them
And last step if all else falls check for a clogged catalytic converter.
Most likely causes:
Dirty or contaminated mass air flow sensor
Failed MAF sensor
Intake air leaks
MAF sensor electrical harness or wiring problem (open, shorted, frayed, poor connection, etc.)

[@nightowl1654]

Hammond Auto LLC thank you so much! I will go ahead and check everything

[@hammondautollc7809]

Your very Welcome don't forget if you find yourself doing the smoke test the car should not be running

[@nightowl1654]

Hammond Auto LLC Do you have am email address I can reach you at? I want to send you a small clip of my rpm gauge because I think that's the problem. It'll be helpful if I can show you instead of explaining to you.

[@hammondautollc7809]

[e-mail]