An SD Premium class on Testing Mass Air Flow Sensors 

Nick Nicu its like little gold nuggets of information that the harder we dig, listen to and soak in however many times it takes makes us more competent techs .

i dont mean to be so off topic but does anybody know of a method to log back into an Instagram account?? I was stupid lost my login password. I would appreciate any help you can give me

@Allen Houston instablaster =)

@Arturo Reign I really appreciate your reply. I got to the site on google and I'm trying it out now. Takes quite some time so I will reply here later when my account password hopefully is recovered.

@Arturo Reign it worked and I finally got access to my account again. Im so happy! Thank you so much you really help me out !

That's awesome man! Thanks for the comment and Happy New Year

Thank you Jeff!

Thanks Kevin!

wyattoneable that's my memory too friend : )

Yeah I hear that Wyatt! Just when I think I've got it, a week or so goes by and it's like I'm starting over again, lol. I'm gonna save this one and watch it over and over until it sinks in. :)

Thanks Smitty!

Thanks so much! If you haven't joined yet, consider SD Premium from my website. You won't be disappointed. www.scannerdanner.com/join-scannerdanner-premium.html

Thank you Billy! God bless you too

Happy New Year to you too Gary

lol that's in the next episode

Gracias Amigo

You can subscribe on my website here www.scannerdanner.com/join-scannerdanner-premium/subscribe-to/3-scannerdanner-premium.html There is a 14 day free trial. Thank you so much! I hope to see you there

Saludos desde los Estados Unidos

thank you my friend, you found the right channel for sure and if you have a code reader and a voltmeter I can help you troubleshoot that yourself

Completely unexpected! Thank you so much! I assume this helped you fix your car? Or are you trying to learn this trade? If it's the latter I would rather see you spend $11 for a month of access to my premium channel than this. If you want, go to the home page of my website and register for a free account, then email me at support@scannerdanner.com With your user name and email address you registered with and I will open it for you for the month. Really appreciate this gesture again

lol nice

Question 1: Yes, this would work 2: If you are jumping to the 5v ref circuit as I did, yes, I suggest a resistor in case you jump the wrong pin or if the signal wire is shorted to ground. BTW the incandescent test light I use works great as a "resistor" here 3:It is a straight path to ground. A voltage drop test on both grounds should be less than 100mv with the sensor plugged in and active.

HE had a video on the 27th or maybe I should say he posted a free premium video. Remember he works the school part time so he can do videos certain times of year so he works part of year, does videos other part and is probably playing or was playing Santa in the past week so he's probably on break as the rest are. This was just a estimated guess.......

Thank you Dale! But I think he was asking about my brother :-) He hasn't been producing videos for awhile. You are correct though with me. When I have a class at the school, it is very difficult to produce videos with the same frequency. I'll be teaching until the end of January then my next class isn't for another two months. So Feb and March should have additional uploads. I need to shoot a video and let people know what goes on behind the scenes. Family, life, teaching, troubleshooting, filming, editing, website, SD Premium move from RU-vid, handling emails, customer support etc etc. There are some that think this is easy :-)

OH Paul...Man, I wonder if you ever sleep. Your amazing to tackle all of that. Been watching for couple years now and I can't even say how valuable you truly are to the rest of us out here. Appreciate your hard work and the drive to continue doing what you do. Thank You.! Yes, please do that full in life video. That would be fun and interesting to see and I think most would come to the reality of the difficulty of juggling all of these tasks. Well, I hope all is well with James, miss his vids. And you can pass that on to him for me too. :) Hope that BMW stopped haunting him. Hahaha I'm sure he would know which one if you asked him. Anyways... Happy New Year to you and you family too. See you in 2018 Keep on Keepin on my friend.! Cheers, Kevin

Just another thing to be aware of (substituted values)

Put the screen back in. It is a diffuser that ensures the MAF sensor properly measures the incoming air flow. Remember the MAF sensor only samples a portion of the air coming in and the screen ensures each column of air is the same flow rate. Look at your fuel trim readings before and after, you will see an improvement WITH the screen installed.

Bad on most

ScannerDanner thanks- thats a straightforward reply, it totally makes sense. I guess the engineers designed it. i can’t “improve” what is effective/efficiently designed Thanks again- your videos are very specific and invaluable sir.

That is correct, no external 5v reference on this design (4 wire). The 5-6 wire one would have a 5v ref but it is actually the signal circuit of the built in intake air temperature sensor. So a 12v feed, 2 grounds and an analog 0-5v signal that is generated completely by the MAF sensor (with is actually more accurately a module) itself.

ScannerDanner thanks for the reply. Also thanks for being willing to give the time and labor I know must go into doing what you do for us. You’ve opened my eyes to so much, and revealed mysteries I’ve wondered about for years. THANK YOU. A while back I got your book from AES Wave, (wonderful information) just curious, do you offer a paper version in color? This is not a complaint, I love the book, just wondering. Thanks again.

Thank you Jeff. I do not have a colored version in print. The eBook is in full color and I do offer $20 off the eBook for paper book owners or vice versa. Email me if you're interested in that at paul@scannerdanner.com Thanks again!

HUNTIN-SHOOTIN- AIRGUNS...I see your question is over 2 months old, and had no response, so I thought I would give a shot! From what he teaches in this video, if you have five volts on one wire, which is the signal wire from the computer, and 12v on both of the other two wires, that should indicate that there is a ground wire problem somewhere after your MAF sensor! Both wires with 12v means that power is getting to the ground side, but not going to ground, with no flow 12v will stay on the ground side! Try this test! Unplug the circuit, turn the key on, use a D.V.O.M. to test the volts at each wire! Unplugged, it should be 5v then 12v then 0v! Turn the key off, and touch the volt meter leads Red to battery positive, then black to the one with 0v in the earlier test! That should show 12v, indicating that there is good ground. If it shows 0v then you need to track down where the ground is open! If it shows 12v, then use a test light, one end to battery positive, and touch the ground wire, that's unplugged at the sensor (just touch the terminal, do not try to force anything into the terminal to spread it open, and cause a bad connection) to see if the ground wire is connected to ground strong enough to carry electricity! If you then turn the key on, and use the test light to the 12v wire, then to the 0v wire, sensor unplugged, to see if the circuit will carry 12v to ground thru the test light as a load, the circuit is in good shape, and I can't tell you where to go from there! If anything else is wrong, then you need to track them down to fix it! If the test light shows good bright bulb when attached to battery, and attached to the sensor wires, maybe try a different load test, like adding another automotive light bulb in the test! It will show if the 12v power, and the ground wires are strong enough, not corroded, and firmly connected! The 5v line is from the computer, and is only 5v, and only comes from the computer, so if it's there, it's there! The sensor is a digital frequency type, and works by changing the frequency of how often per second it is switched on and off, to keep it to a predetermined amount of heat, calculating how much air is being passed over it to cool it off, showing how much air is getting in the engine! One more test I used on my MAF, to determine that it was the issue, I grabbed it just after where the plug is attached, and twisted it a little bit, which caused the engine to stumble a tiny bit, whenever it "glitched" as I twisted it!! That showed me that all of the wires to and from the sensor were in tact, and the sensor mess up was caused by me, so it had to be the sensor, not other issues! I tried to not touch the plug or the wires, as I twisted it gently!! I think I just basically pushed on the sensor body, away from where the attaching screws were, but between those and the wire plug!

Post to my forum my friend, we can absolutely help you and it's free to join www.scannerdanner.com

Yes, ru-vid.com/show-UC_q-0ppmnIRaEYR7LIX8tGAfeatured?disable_polymer=1 He doesn't have a lot of videos yet but he is your diesel guy for sure.

This playlist Rex ru-vid.com/group/PLAFYVCyenqcr32wgsCqa1Zj4335YlBF5p I have one in there with a MAF with a bad ground too

@@ScannerDanner I kind of figured it out but Mitchell diagrams do not show exact location. Only roughly where it is with a partial hard to read sketch. A real pic of the actual location and best way to get to it would have been helpful.

@@ScannerDanner I watched that series twice or five times for some videos. Don't have a 5k ohm resister. Is that something you just carry around in your toolbox? Your early chapters say the test light is acceptable to use. Does that not work for sensors and 5v signal wires? Does it have to match the resistance of your component?

@@rexluongo6470 I've changed that use since I've written this. I use an incandescent test light now instead. Chapter 10 signal circuit integrity classes I cover this my friend

@@ScannerDanner I am on chapter 5 right now. I thought you said in chapter 3 it was ok to use an incandescent test light (not an LED). That is why I asked because this contradicted what you said, but I thought maybe it was an exception because it was 5k ohm resistance instead of 100 ohms like the solenoids in chapter 3. Also, I tried to purchase your paperback engine performance book, but the internet blocked me and your support team wouldn't send me an alternate way to pay. I would think for $100 they would figure out an alternate way to take my money, like zelle or bank transfer, credit card over phone etc etc???? Pretty hard to make a living if you turn business away.

Possibly and Intake air temp sensor signal. It will show 5v unplugged and a drop in voltage plugged in

@@ScannerDanner which means that the maf and iat share a common ground i think?

Correct

@@ScannerDanner thank you so much sir Paul i really appreciate your efforts i always go back to your videos when i'm lost

On a GM? On the signal wire (yellow)?

you can do that

define these codes for me so I don't have to look them up please. Thanks! Yes, 2.67 volts on the signal with the MAF plugged in would be an average of the 0-5v square wave, but that is all that tells us, that there is a signal taking place, doesn't mean it is the correct frequency range. You need to switch your meter to HZ and check it at different loads.

@@ScannerDanner Thanks for taking the time to reply. PO122 TP Circuit low voltage. P1106 Map Inter High Voltage P0102 Map low freq P1122 TP Circuit Interm low voltage P1123 incorrectly listed. Starts up fine, just after warm up ,constant up and down idle. Then stalls. Low cost scope idea? Could a scan tool DIY type be enough to isolate problem.Would a lab scope be cheaper than an auto type? TP sensor with Fluke volt meter is .5 volt to 4.5 on meter. Data obtained turo pro and new thinkcar diag software.

what year, make, model and engine?

​@@ScannerDanner 1998 olds 88 ls 180K Fel pro lower and ATP upper installed, new iridium plugs and wires. New Map sensor. Done by the instructions to solve excess coolant loss. New gasket sets for injectors.

@@ScannerDanner 1998 olds 180K Abnormal Engine Coolant Consumption or Coolant Leak details: www.underhoodservice.com/second-generation-repairs-servicing-the-gm-3800-series-ii-engine/ atpautomotive.com/featured/engine-intake-manifold www.felpro.com/find-my-part.html If degradation of upper intake manifold composite material is found, replace the lower and upper intake manifolds with the following part numbers: Part Number Description 89017554 Gasket Kit, Upper Intake Manifold 89017272 Manifold Kit, Upper Intake Use ATP Gasket included 89017400 Gasket, Lower Intake Manifold replace with Fel-Pro 24508923 Manifold, Lower Intake Not normally needed

When it is not starting, without the jump pack. Check spark and injector pulse as well as fuel pressure. Find out what you are missing then we go from there. I've seen a bad power feed wire to fuel injectors cause this as well as a weak fuel pump

Thanks dan the only thing I haven't checked is the fuel pressure connected to engine I did do a dead head pressure and was good. When it does start I get a lot of smoke from exhaust for a min. Like too much fuel

@@Kc8qdq it's Paul Danner 😉 Anyway, that does sound like a flooded condition. Check your coolant sensor for sure!

I believe the 5-wire has an internal intake air temp sensor. But the MAF circuit is the same as a 3-wire. Which is a 12v feed, a ground and a 5v digital signal that operates at 2khz to 10khz. You cannot jump a 5v ref from another sensor to this circuit. It is a 5v pull-down design signal circuit, it is not a steady 5v ref. The ECM sends out 5v (not reference voltage like what's on your MAP) and the MAF sensor pulls that to ground (on/off) to make a digital signal. It will not be steady as you saw and your voltmeter will be too slow to read it. You need to switch to a frequency scale to measure the actual signal

​@@ScannerDannerthanks for taken the time to respond. First I want to thank you I've learned so much from you 😊 . So I am scoping the MAF signal wire I have the scope set to 20v - 10ms just like you had it setup in a video (GM MAF sensor circuit tests) should my waveform look like you showed in the video ? I have a 04 Silverado 6.0 not sure if waveform changes depending on the year. I've checked the ground and power I've tried different sensors but doesn't look like your example. I checked MAF (gm/sec) and MAF (Hz) they both match each other on scanner . Truck runs fine only issue is P0101 Im pretty sure I checked everything I'm thinking it's the PCM✌🏼

@@charliesolorzano8457 you need to pull up the flow chart for the P0101 code, there are other variables for this code than just the MAF and ECM If you don't have access to service info. You can buy it oer vehicle and for $20 that's what I'd be doing eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=

@@ScannerDanner ok thank you ✌🏼

​@@charliesolorzano8457 yeah, there is a bunch of checks in that flow chart

Send more what Larry?

www.scannerdanner.com thank you!