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GM MAF sensor circuit tests (a free ScannerDanner Premium video)

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ScannerDanner

ScannerDanner

Күн бұрын

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Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner 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 ScannerDanner 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 ScannerDanner LLC.

Пікірлер: 63
@zackarywest8568
@zackarywest8568 6 жыл бұрын
I agree with pine hollow Auto... I have been a diag tech for ten years and have been very successful but been going about my diags the long route. I learn more from Paul than anyone I have ever worked for, with or any class I have ever attended. Period.
@ScannerDanner
@ScannerDanner 6 жыл бұрын
Thank you Zackary
@PineHollowAutoDiagnostics
@PineHollowAutoDiagnostics 9 жыл бұрын
Paul, having sat through hundreds of college lectures, I can say with certainty that your lecturing and presentation style are absolutely top-notch. Your class would be my favorite one of the day for sure! Bet your students never fall asleep behind their desks haha
@ScannerDannerPremium
@ScannerDannerPremium 9 жыл бұрын
Thanks man!
@danieljurgill1681
@danieljurgill1681 Ай бұрын
The MAF circuit design is pull up. When disconnected 5v is the up, or high side. The resistor is in the ECM and the reading the computer sees is 5 volts when disconnected. That is what determines a pull up or a pull down circuit. A pull down circuit will measure zero volts when sensor is unplugged.
@mike-yp1uk
@mike-yp1uk 9 жыл бұрын
i like the bypass testing it eliminates useless testing. i believe in daily training to get greater results in the field. your premium channel is an amazing program.it took my career to a whole new level. great video.
@nickayivor8432
@nickayivor8432 2 жыл бұрын
KNOWLEDGEABLE Sir ScannerDanner Thank you👍 Take care and have a great day Sir ScannerDanner From Nick Ayivor from London England UK 🇬🇧
@steveguest8028
@steveguest8028 4 жыл бұрын
Hi Paul,great explanation of how a GM maf circuit works....Many Thanks
@ozzstars_cars
@ozzstars_cars 9 жыл бұрын
Thanks for sharing this info Paul
@BigMac2222
@BigMac2222 9 жыл бұрын
A quick and dirty way to try and simulate hertz signal is to use a file attached to ground and run the signal probe along the face of the file like striking a match. Also good for pulsed DC switch bypassing.
@ScannerDannerPremium
@ScannerDannerPremium 9 жыл бұрын
Nice tip!
@kylefentz
@kylefentz Ай бұрын
Dang thats pretty cool
@philh9238
@philh9238 9 жыл бұрын
the gm troubleshooting has you check for 4.8-5.2 volts while sensor is unplugged key on. test for ignition voltage, but the thing that kinda is sketchy is they say use an ohm meter to check the ground wouldnt you want to do a voltaGE drop test instead?? also they say use there 900 dollar signal generator tool to simulate hertz nice idea with the test light my friend
@felplayvina
@felplayvina 9 жыл бұрын
The pull down test KOEO it didn't work but it did work for me on gm, I was not sure about the 5 V at the signal wire them I remember pull down test and the scanner read the signal, I was using a maxidas ds708 but it only show ones maybe the scanner or maybe you didn't see it at the first try. Nice test with the KOER..
@danjensen100
@danjensen100 7 жыл бұрын
Paul, sorry but I know I am missing something. You explained the misdiagnosis of the other instructor's vehicle. It needed the ECM not the airmass, and stated that you should have unplugged it to determine it was a pulldown design. But if the ECM was faulty and not sending the 5V how would you have determined that? 0V plugged in, 0V unplugged (with a faulty ECM not supplying the 5V on the signal wire). I've been trying to figure out what the next step would be in that scenario. **Thank you for your time!
@ScannerDanner
@ScannerDanner 7 жыл бұрын
:-) great question. The short answer is now you know, don't forget, all GMs were done this way. This type of info is hard to come by, I learned this one myself.
@JoelAutomotiveInaction
@JoelAutomotiveInaction 9 жыл бұрын
paul that signal does not looks digital square is that normal ?or how do I separate normal square no square of bad square digital signal ? thank you very nice tool your videos
@user-uj1xg7hb2u
@user-uj1xg7hb2u 4 ай бұрын
Paul You Said GM and Ford cars uses same MAF sensor operation?, I mean they both produce Frequency not Voltage?
@jesusmalagon4336
@jesusmalagon4336 9 жыл бұрын
thanks Paul Danner
@DJ-tn7vj
@DJ-tn7vj 3 жыл бұрын
Man Paul.im going premium.lol.cant wait to get my hands on my book.
@ScannerDanner
@ScannerDanner 3 жыл бұрын
Thank you Daniel!
@zlatkomustovic1147
@zlatkomustovic1147 2 жыл бұрын
Great video:) I wounder if you can find problem on maf sensor with digital multimeter if you didnt have scope? What reading to look for on maf sensor ?
@ScannerDanner
@ScannerDanner 2 жыл бұрын
Depends on the failure. Check out my chapter 12 playlist for some more MAF testing videos. In some of them I'm using a digital meter but also talk about the limitations
@markferraro5250
@markferraro5250 9 жыл бұрын
Thanks Paul great video got me thinking do you put a lot of stock in VE calculators ? It's a formula where you put scan tool pids into a formula to determine how well an engine is breathing . Iatn Google has the formula it looks at maf. Temp. Air temp. Baro. Rpm. Engine displacement tps. Just want to get your opinion. Mark ferraro
@ScannerDannerPremium
@ScannerDannerPremium 9 жыл бұрын
Never used a VE calculator.
@johnmwangi6291
@johnmwangi6291 3 жыл бұрын
Can a little corrosion affect the signal wire..? And if so how can you find it..? I understand that there is no current flow but I was just thinking about it.. thank you sir
@ScannerDanner
@ScannerDanner 3 жыл бұрын
Signal voltage on the scan tool will not match an actual signal voltage measurement at the sensor in your scenario. Make sense?
@kylefentz
@kylefentz Ай бұрын
The cycles a second?…….cycles a second of what? I understand its hertz but what is the pcm cycling, voltage to keep the hot film/ wire at that certain temperature?
@ScannerDanner
@ScannerDanner Ай бұрын
That's all done inside the MAF which is actually a miniature module, not a simple input sensor. The MAF signal is simply a representation of all that you nentioned
@philh9238
@philh9238 9 жыл бұрын
ive got one other question you say look for 5 volts to the sensor say you didnt see it would you have to do the unplugging of all the sensors that are on the same 5 volt ref? check pcm grounds/powers? and 5 volt harness for a short to ground??
@ScannerDannerPremium
@ScannerDannerPremium 9 жыл бұрын
Did you see my Cobalt video? It had low voltage on the MAF signal from a reference circuit problem. So a ref circuit problem will affect the MAF signal (GM) but a MAF signal problem will not affect the reference. Make sense?
@philh9238
@philh9238 9 жыл бұрын
so your saying a shorted 5 volt reference circuit or, shorted sensor on the reference circuit will cause low or no maf signal. but an actual maf sensor signal problem wont affect the signal circuit? kinda confusing. i did see the cobalt video by the way.
@ScannerDanner
@ScannerDanner 9 жыл бұрын
Close. A shorted maf sensor signal circuit will not affect the reference but a shorted reference will affect the maf signal
@philh9238
@philh9238 9 жыл бұрын
now it makes sense. what is a low reference circuit that gm calls it?
@ScannerDanner
@ScannerDanner 9 жыл бұрын
phil holbrook sensor ground
@aarongallagher8898
@aarongallagher8898 3 жыл бұрын
My 2002 Lesabre MAF waveform (HZ/time) line was smooth with humps reflecting increase in air volume as I drove. After my engine became hot the smooth humps became really hashed ? Using Scopemeter 98 Any ideas?
@ScannerDanner
@ScannerDanner 3 жыл бұрын
ground connection on your scope changed, MAF is failing, computer grounds or MAF grounds could be an issue, lots of missing information here for me to be able to help you further
@NobodyAskedForThis
@NobodyAskedForThis 6 жыл бұрын
I had the opposite. I had 5v on the signal wire engine running, idle. Power/ground good. 0.0g/s on the scan tool. Engine ran fine. Bad sensor.
@ScannerDanner
@ScannerDanner 6 жыл бұрын
sweet
@Thefox2000unit
@Thefox2000unit 6 жыл бұрын
How do you know if it's "pull up" or "pull down"? If the computer is bad and not sending out the 5v a "pull down" will be VERY misleading. Lending you to think it's "pull up".
@ScannerDanner
@ScannerDanner 6 жыл бұрын
Exactly! Great question and insight man. It is not easy to determine on electronic design circuits, but I have hours and hours of video on this topic on ScannerDanner Premium. www.scannerdanner.com/join-scannerdanner-premium.html There is a 14 day free trial. Even if you sign up and cancel before the trial ends, I'm fine with that. Just watch my chapter 2 "switch inputs" material okay? Thanks! hope to see you there.
@heatherrhodge2588
@heatherrhodge2588 4 жыл бұрын
wouldnt you be able to tell just from viewing the wiring diagram? I'm asking Paul actually...im asking bc another of your videos made it sound like it should be possible to tell if it's pull up or pull down just by the wiring diagram?
@mototechno834
@mototechno834 3 жыл бұрын
Hi Paul..Is it true to say that if the maf is digital we will see 0 or 5 volts at the signal wire with KOEO and if it is analog we will see like 1.2 volts, 2.6volts, 1.8volts or voltage readings like these...i mean if we see 0 or 5 at the maf signal with KOEO, we can be damn sure that it is a digital maf.
@ScannerDanner
@ScannerDanner 3 жыл бұрын
Not necessarily. You can have an analog MAF with a problem, read 5v steady on the signal wire. (Open sensor signal circuit or ground problem)
@mototechno834
@mototechno834 3 жыл бұрын
@@ScannerDanner Hi Paul..when we test short to ground using resistance check by disconnecting the components on both sides, if we see zero ohms, we say it is a short to ground and if its open limit, we say the wire is open...if for example, we see like 300, 400, 1200 or any figure, what does this mean????? bcoz neither this is short to ground nor open. Plzzz advise. Thank you
@johnmckamy6398
@johnmckamy6398 7 жыл бұрын
what size engine is this ?
@danieljurgill1681
@danieljurgill1681 Ай бұрын
Pull up circuit design. Just because every circuit on the planet gets pulled yo ground does not make every circuit a pull down circuit. If it was a yrue pull down circuit it would read ZERO volts when disconnected. Now, when disconnected, it reads 5 volts, 5 volts is HIGH or UP. ,aka PULL UP.
@ScannerDanner
@ScannerDanner Ай бұрын
I think it is ridiculous terminology. What does the "switch" do or in this case, the MAF sensor? It pulls a signal voltage supplied by the ECM to ground. I will not call it a pull-up circuit even though it has a pull-up resistor in the ECM. It adds unnecessary confusion. It's the same thing as thinking about electron flow vs conventional theory. We all know it runs the opposite way, yet we troubleshoot like it's not.
@mototechno834
@mototechno834 3 жыл бұрын
Hi Paul...On what cars can we see pull up design????
@ScannerDanner
@ScannerDanner 3 жыл бұрын
You're a premium member now right? Chapter 2 material my friend. It won't necessarily be car specific. You can have pull-up and pull-down circuits on the same car.
@mototechno834
@mototechno834 3 жыл бұрын
@@ScannerDanner yes paul..i have also purchased the e-book..thank u sooo much
@blazingtonight1
@blazingtonight1 9 жыл бұрын
Can u do some diagnosis on mercedes 722.9 transmission conductor plate and how to address problems with it its supposed to be a common problem but i dont really get it
@prmayner
@prmayner 9 жыл бұрын
are you for real dude? i would suggest going on over to Hiram Gutierrez and ask him. he's the transmission man.
@victorcovarrubias4022
@victorcovarrubias4022 6 жыл бұрын
What do I need to watch videos out of the country?
@ScannerDanner
@ScannerDanner 6 жыл бұрын
SD Premium on KZfaq has been moved to my website. There are no country restrictions and all you'll need is a PayPal account to subscribe. Thank you! If you have any problems subscribing email us at support@scannerdanner.com
@trevordolly4628
@trevordolly4628 Жыл бұрын
My MAF is reading 2,683 Hz at idle on my Autel scanner
@ScannerDanner
@ScannerDanner Жыл бұрын
yep or 2.6 KHz
@trevordolly4628
@trevordolly4628 Жыл бұрын
@ScannerDanner Is that normal for an 04 Escalade with the 6.0? I'm still learning to read live data. It's a whole new world of automobile technology for me haha
@ScannerDanner
@ScannerDanner Жыл бұрын
@@trevordolly4628 not sure, they're all different. What are your grams per sec at idle and what are your fuel trim numbers?
@trevordolly4628
@trevordolly4628 Жыл бұрын
@ScannerDanner 4.5 ish (was reading 0.02-0.01 lb/s) gs/s at idle. St fuel trims were between -1/-4 on both banks. Lt was -25 on both banks. It's got lean codes. I did the intake gaskets around 8 months ago, and they're still good. I soaked them in brake cleaner and the fuel trims didn't change at all.
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