P0101 GM Digital Mass Air Flow Sensor Diagnostics and Troubleshooting by Wells Solutions

[shrEDinsince82]

yeah it dosent move very often i have ve tables modified thru efi live i might try going back to the stock tune file i dont really have any driveability issues just a po101

[shrEDinsince82]

i have the same truck same problem hz is closer but st trm avg1 % does not move 0-200 mark possibly different with solus?? maf gm/sec 8.71-8.62 maf(hz)3075 maybe vaccum leak dtc sets after long idle time or accel

[markjhicks]

@shrEDinsince82 Did you trace the fuel trims like in the video? If they are flat like in the video chances are you have a defective MAF. What DTC is setting?

Mark Hicks

Wells Vehicle Electronics

[polarisforlife1]

i have a 96 chevy pick up with 5.7l 350 vortec i ran the codes on the truck and it said the mass airflow wasnt working and that was why my check engine was on i replaced the part and the check engine is still on and i ran the codes again to see what it was and it said it was the maf can u give a solution to why the check engine light wont go off

[markjhicks]

@polarisforlife1 I can help you with possibilities and a test procedure, but i need you to provide the code number.

Mark

[chevytruck19781]

@polarisforlife1 Ive had the same problem with mine the wiring harness conectors get old and dont conduct well try replacing the end it fixed mine

[mpcross06]

Great video with before and after. Get lesson for us novice EMC guy's. Thanks much. I wish you could do one of these shorties for every code.

[markjhicks]

@mpcross06 I have a feeling you are no novice! Thank you for the kind words. One video for every code....now there is a challenge I like!

Take care,

Mark Hicks

Wells Vehicle Electronics

[DMM9786]

i have a 96 tahoe and changed the mass air sensor because the truck kept shutting off at start up and code was for maf. after i installed new maf it ran great for about 45min then went back to shutting off and rough idle . i went online and someone said to check egn1 fuse> it was blown then i replaced it> it last for 30min then blew again it keeps blowing that fuse what do i do??? any ideas?? thank you!!

[markjhicks]

@DMM9786 Both the Mass Air Flow (MAF) and Cam sensor get power from the under hood fuse block ENG1 fuse.

Inspect for a blown fuse. Replace fuse, if blows again disconnect the heated O2 sensors. Replace sensor causing fuse to blow, inspect wiring to sensors.

Inspect wiring to the vent solenoid, purge solenoid, Exhaust Gas Recirculation (EGR) valve MAF and distributor cam sensor.

I hope this helps,,,stay in touch, please let me know what happens,

Mark Hicks

Wells Manufacturing L.P.

[DMM9786]

i have a 96 tahoe and changed the mass air sensor because the truck kept shutting off at start up and code was for maf. after i installed new maf it ran great for about 45min then went back to shutting off and rough idle . i went online and someone said to check egn1 fuse> it was blown then i replaced it> it last for 30min then blew again it keeps blowing that fuse what do i do??? any ideas?? thank you!!

[nobleheight]

I saw a Bergwall video that showed a Mastertech scan tool displaying engine load as a percent. Percent of what? I don't know for sure, but I am guessing that from a purely academic perspective, engine load is a measure of force which could be expressed in newton-meters. And engine vacuum is directly proportional to this force. Now, if engine load is displayed as 100%, then what is the corresponding engine vacuum reading and force measurement?

[markjhicks]

I believe it would be a percentage of maximum or perceived max. if engine load is at 100% the vacuum reading would be zero.

[nobleheight]

1:08 Once again, does the MAF produce a sine wave or a square wave. The picture at 1:08 is a square wave, and yet the narrator keeps refering to a sine wave.

[markjhicks]

In 1822, Joseph Fourier, a French mathematician, discovered that sinusoidal waves can be used as simple building blocks to describe and approximate any periodic waveform including square waves.

[nobleheight]

The yellow trace is the MAF. What is the green trace above it?

[GeorgeLovesTiffany]

i have had similar readings on my scan tool with malfunctioning maf sensors on older model B body cars

[markjhicks]

Thank you George...if it is at all possible, the next time you get a similar reading save it and send it to me for the records. It will help us determine if this is a defined way to check digital MAFs.

Take Care,

Mark