I just tried a web site that for $2 let’s you ask a question of a mechanic so I asked which is the signal wire on a Subaru forester and I got yellow wire pin 5. This info in addition to this excellent video allows me to follow the direction but jump straight to testing…wow this makes it so simple. Thanks for the great video.
If you mean that the mechanic stripped some of the wire insulation to make connections with a voltmeter (multimeter); then, you got a poor mechanic. Using backprobe pins is the correct way to proceed to make electrical measurements.
Thank for that video it’s super helpful to me. I don’t need to know the sensor resistance… i Just want to know if the sensor is doing it job. Testing resistance is only relevant, if you want to repair the faulty sensor.
Saw that too, does that mean he needs to test the harness? Cuz I’m facing the same issue with a 08 subie. Batt wouldnt hold a charge, replaced it. Buddy wanted the fuel pump replaced while at it for kicks. Cleaned ground spot, replaced the greenish color ground strap, forgot to plug MAF in, neg term tight, started right up. Plugged the MAF in with it running, idled without much slug, and no CELS. Fast forward a couple hours, all crank no start. Replaced the cracked terminals, cleaned up all the grounds batt side, all crank no start, scanner gave MAF codes. It had 02 sensors and cat sensors and VVT sensor codes before. But now it’s just the MAF codes. I thought the batt was the main problem, I guess it was secondary. I about had it with this damn car lmao
Thanks my friend, i enjoyed watching your educational video, except at the point of 6:20 of your video, I'm confused. Where's the ground wire coming from and to where are you connecting to it please?
I’m still confused. Fantastic video except there’s a large gap of knowledge. I’d the negative black lead from multimeter still at the battery? Then introduce a new wire to connect any ground to the ground on sensor? But didn’t we have two wires with continuity “which makes sense because there’s two black wires “
The easiest way to test a MAF is directly in the data stream with your scam tool. No need to damage the sensor connector with paper clips. On a 6.0 liter engine the data stream should read 1 gram per second per liter of engine displacement. A 6.0 liter V8 should read at least 6.0 grams per second at idle. If it's lower than 1 gram per second per liter you need to inspect the engine for vacuum leaks in the intake system. Test for exhaust leaks ahead of the oxygen sensor like doughnut gaskets. If you find no leaks remove and inspect the sensor hot wire for debry or contamination. Clean the wire with MAF spray cleaner. If your data still reads below the standard of 1 gram airflow per liter of engine displacement verify your diag of vacuum and exhaust inspection. Check for restricted air filter etc. if nothing is found replace the MAF. This diagnosis is accurate because you've inspected, repaired and vacuum or exhaust issues. I have fixed many many other techs "come backs" by doing the diagnosis described here. No need to guess this diagnosis is exactly what the engineers use to describe the technique.
@@The77stevo77Test the MAF by reading live data at idle. An accurate MAF will show 1 gram per second for each liter of engine displacement. A 5.3 V8 should draw 5.3 grams per second air flow at idle. If it seems like it's low look for intake and exhaust leaks. If you don't find a leak remove and clean the MAF and retest for 1 gram airflow per liter of engine displacement. If it's still low replace the sensor and retest. Simple and you didn't damage the harness by needlessly back probing the connector and damaging the harness.
1999 Toyota Avalon car with a v6 engine that cranked but wasn't starting. After engine rebuild and gear oil replaced . While test driving by the engineer , smoke started emanating from the engine bay. Precisely, from the fan relay that the car owner connected by himself. Within few minutes, the car shutdown by itself as if fuel is finished. Presently, it's a crank a crank no start, no spark, no injector pulse, check engine light staying ON with ECU connected or removed. I tried to scan for DTC codes, but my scanner wasn't communicating. I checked all fuses, power and ground at obd port, those checked ok. but my scanner isn't compatible to read CAN network. There are only 4 wires intact for the obd2 port. Furthermore, I added fuel through the intake to the engine, no change at all. I checked for spark and injector pulse. These things weren't present. But there was power to injector with just the key at ignition or ACC and COP had 1 ground and 1 power as usual. With the ECU removed battery connected, Engine light would come ON. with ECU connected check light still comes ON. Before I left, I checked the MAF sensor 5 wires and noticed that 3 wires were earth instead of 2 and 1 power; no ignition current/ power was available for the remaining 2 wires. Please, what should I do to get this car running again?
I AVE MERCEDES BENZ C220 OF 1996 , NOW I AM FACING THE ABOVE PROBLEM, LIKE ENGINE RPM GO VERY HIGH, BUT THERE NO POWER TO PULL THE CAR, ITS STARTED SHOWING THIS PROBLEM RECENTLY, IS IT RELATED TO MASS AIR FLOW SENSER, AND ALSO PETROL CONSUMPTION ALSO INCREASED, ?EXPECTING SOME REPLY FROM YOU,
Thanks for the great video, Mate. How do you know that the yellow was the signal wire, for the red meter probe to connect to, or does it matter? Could you have put the meter probes on the other way and it would have read negative; or would it cause damage? Thanks again, my friend🙏👍
@@PhillipsVision thanks my fry. Would it matter if you put the probes on the other way round, or would the value be the same but negative. Thanks again.🙏👍
You say after excluding the 12v power and two ground wires, one is left with the signal wire and sensor ground. . . But of those two, neither tested positive for ground continuity. How could there be a "sensor ground" wire that's negative for ground continuity?
Impressive no guess work I've seen so called mechanics not do those tests and changing buy chance which costs us all .fab guy awesome keep up the good work !!!
Andy have a 2011 2.4 Equinox.Codes saying bad intake and exhaust solinod.Rreplaced but still runs rough making sound out of timing chain cover.When unplug solinod intake. sensor helps.Very confused what wrong.
@@kelvinsmall2552 sometimes those aftermarket parts can be subpar and cause issues. I’ve had good and bad experiences with them. Make sure you are also getting a solid connection when you probe the harness
How come you didn't do a before and after test.. That way you could prove that the new sensor works better like what you said that it increases slowly upward...
I don’t believe there is a specific fuse for the MAF sensor. If you’re not getting power, you may have a break in the wires that need to be replaced. Here is a link to a video I did showing how to find a break in wires: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-714_57IRwkk.htmlsi=SDTRjuy1pTdckBIc
I have code 106 and 108 the car starts but sounds ruff idling think its map sensor or wire any suggestions ihave changed spark plugs coil packs mass sensor now order map sensor
@@kylebrewer6686 the codes you are getting pertain to the MAP sensor. When those go bad you will get rough idling among other things. Replacing it should solve your issue.
@@esdeynnahernandez4964 start you car cold, watch the RPMs. If it’s working fine you should hover around 1.5 RPMs and gradually drop to around 600. You can also take it out and visually test it. The plunger will open and close.
You are not clear where you finally plug the positive and negative of your multimeter. Not so help full. I know that you plug the positive on the signal but what about the other one?
Don’t Chevy’s use a frequency style maf. Meaning unless your multimeter if set to frequency (hertz) it’ll just get an average measurement making this test inaccurate
I had a black wire with 12 volts and a white wire with 4.49 volts or signal wire. Red was my ground. LOL Since the car won't stay running after starting it, it's difficult to test it. I was hoping for a standardized resistance between the different pins or something like that.
My 95 lincoln mark viii motor, in my 67 f100 seems to snap and pop and crackle when its cold. I notice it as the temperature gets cooler towards the fall. I've cleaned the MAF but it still does it. Any suggestions.?
hello there! i have the 2015 verso 1.6 diesel and the check engine light comes on with a p00bd fault code which refers to the mass air filter. i've done everything from changing the maf sensor to cleaning the air intake manifold but the faults pops up again and again. my electrician has inspected it twice and sais there is no wiring problem. any idea what it can be???
Great video! Got a little confused with the final testing part - are you testing the yellow and orange wires together or Yellow to Ground and orange to ground (2 separate tests)?
I've always had intermittent issues engine management issues with my 03 Chevy Express. It sat for about 7 years until I recently needed to get it back on the road. It ran fine then it stalled on me and I had a MAF code. I found the tube for the intake popped off the piece that attaches to the throttle body. FFS
Hi Phillip Great video I have a 2009 Murano V6 I replace the fuel pump but still no start spin over good I can hear the pump run when I turn the switch on, can I still check the Mas air flow sensor if it's not running Thanks
Yes, but doesn’t sound like the MAF, could be the fuel system or ignition system. Make sure the injectors aren’t clogged or the ignition coils or spark plugs are bad.
@@PhillipsVision Hi Phillip i check It now I have a U1000 Code on the 2009 Nissan Murano is there anything I can do to fix it Thanks again could one of the sensor be bad
I have a 04 Vortec 4.3. I have a rich reading in both O2 banks. And a MAF reading in the 7’s at idle and 12-14 at 1400rpms. O2 short trims are in the -20’s. Not sure what’s causing the rich running. Pretty stumped
@@PhillipsVision do you think a bad spider injector can cause it? Fuel trims are in the negative as it’s trying to reduce fuel. O2 banks on both side are showing rich. maybe the MAF is showing high to compensate for the amount of fuel that’s being dumped in?
At back probing You show where you connect the red lead of multimeter. Next you say you Connect the multimeter ground to the other....other what ????????? Ground ? Other back probe? Other. What.????
Yeah I was following right up until he got to the signal wires. 12v battery power and Gnd continuity check made sense. But there was no closeup of the back probing other than showing the first copper wire being inserted on that one pin. Are we to assume the remaining wire that was not a Gnd had a probe inserted and the multimeter was attached to those? Aren't those the air intake temperature sensor leads? On another video, it showed if your MAF has 5 wires, there is an IAT. Was that the case on this or not? There is still some info lacking to me.
Sir…good step by step, however on your back probe description, you put your stripped wire in the sensor line, but what wire/line was the red multimeter probe inserted. Thank you
He definitely didn’t explain this well. From my understanding he backprobed the 5V wire and the only wire left after finding 2 grounds, the 12V and the 5V. That wire would’ve been the one all the way to the left if looking at the front of the connector.
TIP: Use an analog voltmeter with a needle (not a DMM) to measure voltage swings with gradual rates of change. It's easier and gives a better, more meaningful visual representation.
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