Thanks for making a video, but you might have wanted to point out that this only works with MAF sensors that vary voltage on their output, where most will vary the frequency. The latter you would need an oscilloscope to get a useable reading. So, it would be difficult to know which type you have which would negate the useability of this testing method. My particular MAF sensor varied frequency, and so it just had a constant 2.8v that didn't vary with rpm. The new one was an non-varying 3.1v. Thankfully the new one did fix my problem, but the testing method didn't work in my case.
Exceptional video! Explained well without all the extra dribble 99 out of a 100 how to videos have. Maybe you should do a how to video on how to make a how to video, he he.
Very helpful. The holes in my wiring harness are too tight to accommodate a nail, and the paper clip ends are too blunt to get in next to the wire. I used a couple sewing pins, which are kind of T-shaped. They're sturdy, yet you can bend them away from each other once the pin end is inserted. I imagine pulled-open safety pins would work, too, or even straight pins. I tried using twist-tie wire, but it was too weak to allow it to be pushed in far enough.
good info as always thanks for sharing.so the idea is to put the voltmeter on the re ferns and censer ground wire to find the movement of tps as voltage changes.
Awesome. Thanks. So now that I know how to test....if I have a new MAF sensor and new wire harness and figured out which wire is the sensor wire, and the sensor wire stays at 10. No fluctuate with throttle. Yes my truck runs like crap. Chevy 2500hd 6.0 gas 2002
Hello, there. Great video andn really well explained. I have a w203 c180K 2004, and since last year when starting the car, it started taking longer than usual and the car started to have misfires when in lowgear and it seemed it like it would die... Took it to a mechanic and he disconnected the maf sensor, and the problem stopped "chocking" but the start still takes a long time when i turn the key... I bought a new MAF sensor to replace it, and lo and behold, the problem persisted.... So I so some of your videos of how to test the maf. And guess what i found. On the first step, when looking for the 12v pin (it has 04 pins), i tuned the key on, grounded the multimeter, and set do 20dcv... and guess what i found... 12v on 03 pins and 0v on one... Now, my questions is.... What might be the problem? I live in Brazil, and where i live there aren´t many people that understand how german car works. Got any tips for me? Thanks and looking forward to a reply.
This was a good video just to understand the basic system and how it works. I am having problem the MAS sensor sending a signal that is two high and the computer switches over to a automatic mode to let the car run but not entirely correctly. The light comes on. Anyway I was wondering that if I am having compatibility issue with aftermarket versus factory bosch sensors and the volvo computer doesn't read the china sensor outputs correctly. I have tried three. Of course they make the factory sensor so freaking expensive. It is almost unaffordable to drive a Volvo and get it repaired. They have everything so controlled and tied to the factory. Anyway. This gave me a better understanding of what is going on and I think I am going to play around with a potentiometer and change the signal to the computer to see if I can trick it into leaving the light off and not throwing a code. Anyway. Its fun trying...
Make sure you don’t ground out the + wire. Also keep in mind you can create false codes by disconnecting sensors with the key ON. Don’t throw parts at ghost codes you created yourself (or others created). Hence the importance of erasing codes and and seeing if they still persist. That’s why scanners with LIVE DATA can have advantages. Also you don’t want to trigger a “Limp Home” mode with decreased performance from triggering “False Codes.”
Which one? There are two shown at the beginning.I'd go for the bigger of the two. It's very similar to the Rapitest DM25 I use. Reason I have that is because it can read mVac. Without mVac you cannot test ABS sensors or crank/cam sensors
good video, my maf’s got 8 pins so, so much for that process of deduction to figure out wats the sensor ground. speaking there-of, what’s the difference between constant ground & sensor ground?🤔
Thank You for the great video and information. That engine compartment looks exactly like mine, 2003 f150 xl 4.2l. If my MAF sensor is bad, How do I remove it from the breather tube? Again Thank You
Hi, I am in the process of repairing the mass air flow sensor connector wiring. As a result of the mice messing around, I cut the wires off the connector side, leaving approximately two inches for each wire attached to the connector. I thought each wire was a different color, but I was surprised to find two wires of the same color. I drive a 2006 Infiniti M35 with a maf sensor that has 5 wires in this order from left to right: red, black/white, white, yellow/green, black/white, so I connected the 3 different colored wires and was left confused about the two Of the same color. I tried connecting this to this and vice versa and I did not feel any difference. I also tested them with a multimeter and they both gave the same measurement. So if you have any idea or suggestion that can help, will be appreciated
What if the spark is checked good and the fuel rail pressure is good but will not start when cranked? Will any test on the MAF show any information if the car will not start? Thank you for your efforts, been watching many years.
My seems to be holding steady and the voltage increases with throttle and decreases nicely, yet my car still throws a p0102 error code - low voltage to MAF. Maybe it is the MAF then
How to connect maf sensor output ( LB/RD) wire #5 How to connect maf sensor signal return (TN/LB) wire #4 How to connect signal return which is GY/RD wire #1 This is for ford windstar 2003 maf w/c is 6 wires, the #6 is IAT sensor output #2 wire is 12v #3 wire is ground Thanks in advance
U R a Bad Bato my friend! Excelente video and clear understandable explanation and steps! Keep up the excellent videos and thanks a million! Good Brain CACA !
Hi, just saw a video where someone just unplugged the connector and when the engine stops, it's not broken. Is it that simple?? Why do you need to measure?
I read that and tried it on my 2001 bmw 325i. While connected it stalls and shuts off but disconnected it runs. Buying one today but it has been running unplugged for 3 months.
Can you test the MAS if your truck won't stay running. And can a bad MAS cause it not to start or to die within a few seconds or cause surging when idling
Great idea, that would work well, but I'd seriously suggest you get someone else to drive while you watch the meter.ORUse one of these amzn.to/2m439QG and Torque Pro on your phone. Use the graphing function if you can't find an assistant to drive for you.
on my explorer 92, i get code 157,158, low and high voltage codes, check engine light on , I get .01 . check engine light off i get .53 . it is an intermittent thing. checked wires for shorts, none, runs crappy at idle and when driving it will stumble slightly right before check engine light comes back on. I can also unplug maf and plug back in check engine light goes off. yes I cleaned contacts just to make sure it wasn't a short at plug. my question is, would this indicate a faulty maf or one thats getting ready to completely fail?
My multimeter is hooked up as described but my engine will not idle (it dies) unless I disconnect the TPS. Is this test accurate with the TPS disconnected? I'm getting around 5v with the TPS disconnected at cold idle. The exhaust is horrible I assume from a ton of unburnt gas. This vehicle (1990 Toy 4x4 pickup 3VZE Calif) has 7 pins at the MAS connector (3 hot 5v, 5v &12v, 2 Ground, a lead to the ECU and a THA) because the MAS has 3 functions. 1. MAS (Air Flow) 2. Fuel pump shut off if the engine dies for safety & 3. Air Temp in MAS. Isn't RU-vid wonderful? It almost sounds like I know what I'm talking about. Not!
5:02 The voltage is higher on cold start because the pistons are sucking in more air because the idle motor is letting more air at cold engine and therefore the sensor is reading this extra air that comes in.
thats what he said... the rpm is because the engine is spitting in more fuel so that it can start properly, it needs more fuel when cold because fuel doesnt vaporize properly when cold and also cold air is denser when it comes to oxygen so it needs more fuel per liter of air
Dude, your RU-vid thumbnail shows a VW MAS. What the crud man. That is not a Vdub. I have been Hood-winked. Bam-Bo-Zeled. Lead ash-tray. TDI Love from Chicago...
Question; in this case, would it really matter which of the ground wires you used in the testing? They are both constant grounds here, are they not? Or battery negative for that matter? When testing the voltage from the signal wire I mean :)
Yeah but how do you test this if the car won't stay on without aplying gas? If a mass air flow sensor goes out, the most likely problem is that it won't be able to maintain idle so being able to test it without the car running is very useful.
I was doing maf sensor test on lexus is220d.I had ignition switch on position but engine was not running. I have found 12v wire 5v wire connections.I tried to start the engine know all light come on dash but car is not cranking. before the engine was running. Can you tell what might gone wrong.
I have nissan murano 2008 and fuel consumption is too high....I change plugs,clean the fuel injector and air filter change ,but no benefits at all. 25ltr _ 100km I need advice, what is the problem in the vehicle?
