You nailed it! I abandoned the plug ground cut all the wires twisted together, extended the wire, wire nutted them together, added a ring terminal at the new ground end, put on ground bolt in front of battery, added star washers to insure a good ground and it runs like a dream. Shame on Chevy engineers for not using a sealed plug on the ground. Great post, thanks
I was wondering if you could do that. My ground runs under the engine somewhere, no idea why it just didn't go directly to the ECU because it runs right past it. I wonder if it goes to another sensor but I will just cut it and ground it.
Excellent video and great information. I agree, parts changing is going on in too many places and the customer has to foot the bill until the real cause is revealed. Thank you ScannerDanner.
Excellent investigation leading to a 100% pinpoint of a diagnosis.Which takes me another large step away from the the ignorance of being a Parts changer towards a proper diagnostic technician..You da man...
Quality work done there! We need more people like this in shops! Idk how much the client was charged, but I hope they see this video and understand that someone actually cared enough to take the right steps and not just charge for more parts they didn't need.
I see a lot of cars coming from other "part changers" workshop,I usually tell the customer if i can't fix you don't pay as its not fair to them when you throw parts and labour at their expense,great vid Dan,love it,btw my wife thinks its strange when iAm in the hot bath watch your vids....
Atleast she's not the one in the hot bath watching his videos and trying to explain it to you. Because.... that is what i am doing! My husband just got so frustrated by that air ratchet he left the room. Its been 4 months without our 4th gen 4runner PO102 PO113 husband doesnt really ... atleast i dont think he does much troubleshooting. He goes strait for the heart. So he dropped the fuel tank and changed the fuel filter, tested the pump it was ok. New battery cleaned the maf sensor cleared the codes and it didst come back. I know cause i checked. I ran the obd2 code reader and no code when in the on position. Crank no start. Nothing really before this happened. There was a few times fuel was low running on fumes. I remember driving away from the gas station the car didnt have much power. Then going home on another occasion up a bridge didnt seem to have the normal 4.7 v8 power. Then my hubby drove it fishing went to a friends house and no staet. Couldnt evrn jump start it. Towed it home and here we are 4 months later and we are freaking broken. Sucks being poor. Marry 4 money hirls dont do what i did... married4luv. 56 no car, feel freaking hopeless. Scanner Danner must be from Ohio. Me too. I can tell from his accent unfortunately im now in he double ll new orleans. Okay then bye
So glad I found this video my 01 Malibu had no power to the maf sensor after watching this video located the ground found it unplugged and plugged it back it in. Now my car runs smooth and accelerates perfect and shifts great now you guys rock and thanks for saving me a ton of money and headache 👍
Excellent video! I had intermittent maf error code for past three months or so which was getting worse with time. I used to be able to erase the code and it would not appear for a few days. Lately when I erased the code with my Foxwell the engine light stayed on. I tried tracking the fault down but to no avail. Being the cheepy that I am I finally bought a new sensor however nothing changed. I came across your video and decided to troubleshoot a poor ground. Sure enough with the help of the vehicle's manuals I was able to find where the Maf ground wire together with 6 other ground sensor wires on the same lug were connected to the engine. The lug was all corroded and two ground wires to sensors, one of which was the maf ground wire, were totally eaten away. I cleaned everything up and resoldered all the ground wires to the lug and now I no longer get the error code! Pretty sure the problem is solved now but time will tell. Thanks for your very helpful video. Could not have solved the problem without it. You saved me BIG bucks! Thanks again.
Very Helpful Video. Thank You. Daughters Mercury Milan lost engine power, I scanned the ECM and got P0102 and P0113. Doubtful both went bad at the same time I figured another problem like wiring. After your video I found and fixed the ground connection. Now all is well. Problem Solved. Thank You For Taking The Time To Do This Video.
Exactly the same issue I'm searching for. You could say I'm a good woman.a darn good woman. Obd2 codes are PO102 AND PO113 2008 Toyota 4Runner crank no start. It's been 4 months without a vehicle and I'm going crazy. Trying to help my hubby. Watching videos cleaned maf, replaced battery , first off hubby went strait to the fuel pump and filter. Changed the filter, pump was OK.
I'm sorry to hear that. Unfortunately my field is full of them. Too many in my industry have not learned proper diagnostic techniques. The percentage of good diagnostic techs is very low. It is disheartening for the car owners. My advice is once you find a good one, is to stay with him. Give him a chance even if he makes a bad call once in awhile. We cannot be 100% in every "call" we make. Just as a doctor doesn't get it right every time either.
Thank you! I bought a truck at auction that ran terribly, had major and obvious exhaust leak. After fixing that it still ran lean and threw p0102, p0101, and p1351. Started checking grounds and cleaning them and sure enough, the rear engine block ground wire off the MAF strand was disconnected. It was covered in oily goop so must have been that way for a while, engine now runs normal for its age and no more codes.
03 Impala 3.8. Engine code 171. High idle after warmed up. Mechanic said it needed a MAF, same problem, then an IAC, same problem, now he says it's the computer. Seems like another parts changer. So now I'm trying to research the problem myself. Great video!
Thanks for confirming this. Can't find any vacuum leak yet. Although I did find a TSB about clogged fuel injectors. But why the high idle? 3000 rpm sometimes.
metalmoto good question, sounds like multiple issues maybe. a vacuum leak or low fuel psi will not cause a 3000 rpm idle speed on your car. If it was a MAP engine a vacuum leak generally causes a high idle but a MAF engine will generally idle low. So I do not think your P0171 and high idle are related. Hard to help anymore without seeing the car. I would need data. TPS readings at idle during the high idle issue would help. Also STFT and LTFT numbers at idle and 3000 RPM
Worn out throttle body would cause this. Either get it re-bored or replaced. Cleaning it can make it better or worse. I've seen this code caused by cleaning up a worn out throttle body. I can explain how and why it's caused by the throttle body but it's a long explanation and I don't think anybody is reading.
Ill just leave this here . Its from a comment a guy had about watching your videos while taking a hot bath. I replied... Atleast she's not the one in the hot bath watching his videos and trying to explain it to you. Because.... that is what i am doing! My husband just got so frustrated by that air ratchet he left the room. Its been 4 months without our 4th gen 4runner PO102 PO113 husband doesnt really ... atleast i dont think he does much troubleshooting. He goes strait for the heart. So he dropped the fuel tank and changed the fuel filter, tested the pump it was ok. New battery cleaned the maf sensor cleared the codes and it didst come back. I know cause i checked. I ran the obd2 code reader and no code when in the on position. Crank no start. Nothing really before this happened. There was a few times fuel was low running on fumes. I remember driving away from the gas station the car didnt have much power. Then going home on another occasion up a bridge didnt seem to have the normal 4.7 v8 power. Then my hubby drove it fishing went to a friends house and no start. Actually crank no start.. (the dreaded) Couldnt even jump start it. Towed it home and here we are 4 months later and we are freaking married4luv. ... 56 no car, feel freaking hopeless. Scanner Danner must be from Ohio. Me too. I can tell from his accent unfortunately im now in he double ll new orleans. Okay then bye. Also changed the start plugs. Noticed a oil lead from valve cover bolts? He said they were really loose. So there is some oil leakage that's covered some things. He says it's normal... me ... It's a computer.
get me some voltage measurements on the MAF with the key on and engine off and I can help. On your Toyota, it is an analog signal, not digital like this GM, so it is even easier to measure
@@ScannerDanner Hey, sorry for the late reply. I've been watching videos trying to find out how to get the voltage on the MAF sensor. I started watching your masterclass on that. Then my husband's brother came by and they were convinced it was a crankshaft sensor but I don't want to just throw Parts at it do you have any videos that would point me in that direction do you have a link that would be great he's got a voltmeter.
@@ScannerDanner we are on our way out now. I do have a live reading when I ran the obd2 the maf was 1.50 IaT c° 35 Baro 101 eq rat 11 Eat113 Be right back with a voltage reading and I'm going to check the obd2 scanner a little better. Thanks again.
good question. what you have to remember is this circuit is monitored for frequency so a circuit low code means low frequency not low voltage. hope that makes sense
Hello there ScannerDanner, and you're so right. There really are a lot of parts changer out there. I sometimes play in left field, lol . But I do appreciate your videos. Thanks a million.
Yes ! I took it for a drive this evening to "re- enact" the DTC trigger, at 100 km/h, the check engine indicator came up on the instrument panel & I had the Bosch scan tool plugged in. I got the P0332 code to show up on the scanner & that's with all the air leaks fixed,it ended up being the case that I have to replace the rear knock sensor on the LS1 engine. The one I currently have fitted comes from Hong Kong so no more of them,I'll pay about $88 AUD for a good fuel miser branded one. I know the loom is o.k. because I soldered new connectors onto the loom & both sensors read at 100 k ohms. The rear sensor has the case of triggering a DTC due to a low output signal.
So True,About "Parts Changers"!!!!!!!!!!!!!! The easy way Put,and still no fix,and The cust Pays!!!!!!!!!!!! Thats why Its easier to BE HONEST!!!!!!!!!! Word of Mouth Goes faster than the Internet,!!!!!!!!! Nice Job,,,,,,,Jack
another good video,thanks; that's why I always measure the input voltage against the ground wire/terminal right *ON* the sensor,i don't care about the ground elsewhere.
I see all the comments about parts changers and agree totally. I think the problem is that auto repair shops would rather take a risk and throw the most likely part at it, instead of doing these sorts of tests to really know they are throwing the right part at it. I even wonder how common it is for a repair shop to have a professional scanner like a Verus or Vantage Pro.
There's no way that I would be on that air ratchet. When this electric cowboy is giving golden info. I can learn how to put a bolt in threads with a air ratchet later. I want to learn what scanner has to teach.
Excellent diagnosis! I had a similar issue with a Monte Carlo. Customer was irate as had thrown parts at the car for a P0102/420. As you can imagine not cheap. I did some checks, and it was the charging system. Alternator was bad.
u don't need a Verus to do what i did in this video. it could have been done with a multimeter and a basic scantool. although to see the actual waveform that i showed at the end u would need a scope for that. look into the picoscope. or maybe the vantage pro. the vantage pro has the advantage of an awesome database and the picoscope has the advantage of just simply being a much better scope.
depends on the current flow of the circuit. Higher current circuits will have higher ground voltage levels. Computer and sensor grounds should be less than 100 mv
this is a twelve volt supply. the 5v is the signal circuit. if you have my eBook refer to Section 2 for this MAF circuit design. sorry to much to type here
that is correct but it would depend on where in the harness the sensor ground wire was corroded. if it was in the last leg on its way to the computer yes it would affect all sensors. if it was on an individual branch it would only affect everything on that branch
Sir you are having a good video 👌 I got lot of knowledge and experience and helping See some people's don't like problem is those assehole don't understand We love you Mr Paul
Nice, I have to check on mine truck ,because when the scanner is connected, I saw the maf sensor wont move at all ,is at 0.20lb,I don't notice anything if is plugged or unplugged.
Oh my brother, thank you so much for posting this demonstration of how to look for when you have a related problem,my car was jerking and throw me code 102, I watch your video and after that I star troubleshooting, and I fucking found the battery bracket loose and making contact with the positive of my battery, again thank you much,like and subscribe 👍👍👍
Once again, you're the best automotive electrical troubleshooter out there, and if I was still in the 'burgh, I'd be signing up for your class. Now that i am done sucking up, I know the MAFs are measured in terms of Hertz/kHz, which means something happens every second. But what? How is airflow translated to a frequency unit of measure ?
How many Ground splice connectors typically does a car have. I have a 2000 Lumina and was wondering where they were located but cant find a diagram anywhere. I also have a P0102 code right now on the car which is also a 3100. Going to test everything tomorrow with my multimeter
I have a 2001 Chevy Malibu that just cut off on me while driving. I was told a few things and none of them have been right so far. Now I have a friend who asked to see what's up with the car and when we tried to turn her on we had smoke rising from under the car somewhere. My question is could that smoke be coming from the connection terminals to the battery or the starter. I'm really not to big on working on cars nor fixing them but your help and guidance would greatly be needed
LQ4 /4L80e Code P0102 low voltage maf sensor I have ground,12v, 5v. Across 3 Maf sensors,1 that is new. Cleaned TB front and back. New tps and iac. Have not found any vac leaks and tried 2 different intake set ups. Idle is 650, surges/lowers when put in reverse. Hesitation/bogs if I throttle to fast. No other codes Stumped.
I'm assuming this is a GM? What is the frequency of the MAF signal with the engine running? Should be about 2khz at idle. The 5v wire is your signal wire and it should be a pulsed signal
Well done ... I have a question... Got a 99 chevy suburban within the past 5 years it slowly A- starting running good then rough and now very rough, B -gas gauge fluttered a little, got worse and worse to now full on flutter on "Full" and C random shit is shorting out once something is fixed ... for instance ...AC dashboard switch (medium low) grey wire burned out... once that was fixed the 3rd or Medium high burned out wire ... once that was fixed my 4wd actuator started shorting out... then battery drained...then rear driver side tail light mother board burned out (bulbs were black and mother board smelled like burned plastic)... then alternator dies, battery again, window motor driver side burned out (melted plastic) ...Blower motor wire burned ...etc ... ALL right after another ...all electrical and it's running very rough now, (idle is rough but runs good on highway), random misfires codes po300 came on today while trying to fix barn door lock then went off and came back intermittently, abs light came on last week as well and gas gauge flutters (need to look close-flutters so quick) at full constantly. One mechanic said it was engine rebuild, another said fuel pump and another said Fuel injector(fuel spider) ... I believe its just a bad ground somewhere... possibly in the back near the gas tank??? b/c my driver side rear defroster in window do not work (passenger side does) and also I replaced my driver side rear tail light mother board three times already(including last week)...once I replaced it the ABS light came on... I jiggled the copper connectors for my rear barn door (driver side door) door doesnt have wired connectors, instead it has those copper pins or connectors sticking out... while doing this with a friend we noticed gas gauge would stop fluttering and go down to almost empty fuel gauge (which I think is where it is at) ... that's the first time I saw the fuel gauge NOT flicker in 6 years! and misfire codes disappeared as well ... any idea? Am I crazy or what ... also- I sprayed electrical cleaner on ground under driver side rear (strapped on to fuel line connected to gas tank and my friend put his hand on it and swears he felt a tiny shock ... I did it a minute later and didnt feel anything... any ideas? I'm desperate but determined and also, everything that goes wrong electrically (in case I havent made it clear) seems to go right after the other- which is why I think it's a grounding issue
Watched a lot of your videos. they're a great help. But ran into something that has not been mentioned anywhere. My sons 1998 Pontiac Transport 3.4 l. In this you talk about a 5 volt square wave and its a pull down circuit. I ran done every thing as stated , 3 wire connector as you show there. id the three wires. we have three codes of P0102,P0300, P0440. starts ok when cold but warms runs bad, and stalls if you let it, hard to restart. all went ok till the signal wire to either battery ground or sensor ground at plug with a volt meter. with motor running instead of 1 volt and ramps with rpm increase it reads a 4.45 volt regardless of rpm and or either ground. Cant seem to find anything on it. Was told that MAF was bad and replaced it to have same issues. Thanks for any help.
Thanks for the video very helpful I have a 97 chevy truck with a p0102 code so when I check the wire with a light tester the truck shut off right away could it be the same as the video ( 2000 chevy Malibu MAF ground problem )
yea i had the same issue on my 2003 impala. but couldn't find the ground break. so i did a direct single wire hookup to the sensor plug and to a bolt to the engine block and all working again.
Hi Paul Is the trouble code Said single Circuit low. Doesn't that mean Signal shorted to ground or open in the Circuit? If it's a bad ground Shouldn't that mean Signal circuit Highd? Great work and thanks a lot, Jeff
no it does not apply to nissan and toyota they are analog type mass air flow sensors. the only time I apply the terms pull ups and pull down are with digital signals.
Got 99 buick regal ls....stutters when accelerating. Changed spark plugs and wires....whoever had the car before tore the boot for the #4 plug and wrapped tape around it so it super coroded and broke off. That stopped the misfire, but i also had a p0102 voltage high code. Cleaned the maf sensor and it worked fine for a while that day then the code came back. Should i just change it or do a little more digging.
I replaced the MAF on my 2009 enclave as well as the purge valve AND the ECM ($800+) and I am STILL getting code P0104 (MAF sensor), and sometimes P0201 (ECM), C0104 (unknown) and P0104 (unknown). Any suggestions?
what if I have a 03 honda accord 2.4 with a P0102 Maf voltage low, no matter how much time I spend looking for a maf sensor can' find one neither to test not to check 🙄
lol on the sucking up part. don't you mean how is frequency converted to air flow? it would be the same way every other sensor is converted the engineers write in a ROM lookup table what the value is in there you have it. wish I knew more about that part of the industry. I have to go back to school for electronic engineering
Great video Paul as always, I see too many 'parts fitters' which annoys me as a little bit of thinking and checking will usually fnd the problem. Just to confirm then.. 100mv and below is considered a good earth with the circuit loaded ie key on with current flowing?
My 1999 c1500 Suburban with 5.7 vortec has a 4 codes going off for maf and crank sensor think it could be a ground? I put new crank sensor in and checked connections look good
Please post this to my forum. It is free to join. www.scannerdanner.com/forum.html I have over 17K members world-wide and I also have paid moderators who are there to help me help you guys! Thank you for understanding. Hope to see you on the forum!
Great Video Paul, just a quick note, if sensor ground is shared across multiple sensor , and if ground is corroded it would impact all sensor not just that sensor, is that right. since it is single wire , impact on one place would impact rest of the points as well.
P0131 - GM = HO2S Circuit Low Input Conditions Location Bank 1 Sensor 1 Cause Engine running in closed loop, then the PCM detected that the HO2S-11 signal that was less than 250 mv (less than 97 mv on VIN 1 & K engines), condition met for 2-4 minutes.
SCANNERDANNER, can you please make a youtube video explain the differences between a MAF and MAP, they seem like the same thing to me and i don't understand the differences between a MAF and MAP. What car components , car modules, car sensors would a car technician measure the frequency, PWM, duty cycle, can you please give a bunch of examples of when measuring the frequency, PWM, duty cycle, for what car modules and car sensors?
Hello. I have the same code on my astro van 96. I already replace a new maf sensor. But the code still showing on the scanner. Any ideas to my problem??
You nailed it! I abandoned the plug ground cut all the wires twisted together, extended the wire, wire nutted them together, added a ring terminal at the new ground end, put on ground bolt in front of battery, added star washers to insure a good ground and it runs like a dream. Shame on Chevy engineers for not using a sealed plug on the ground. Great post, thanks
I was wondering if you could do that. My ground runs under the engine somewhere, no idea why it just didn't go directly to the ECU because it runs right past it. I wonder if it goes to another sensor but I will just cut it and ground it.
Excellent video and great information. I agree, parts changing is going on in too many places and the customer has to foot the bill until the real cause is revealed. Thank you ScannerDanner.
I’m a automotive student, but tell y’ll what, I love this guy explanation!
Man I wish he was my teacher.
Love your videos Brother 🙏
Thank you!
Excellent investigation leading to a 100% pinpoint of a diagnosis.Which takes me another large step away from the the ignorance of being a Parts changer towards a proper diagnostic technician..You da man...
Quality work done there! We need more people like this in shops! Idk how much the client was charged, but I hope they see this video and understand that someone actually cared enough to take the right steps and not just charge for more parts they didn't need.
I see a lot of cars coming from other "part changers" workshop,I usually tell the customer if i can't fix you don't pay as its not fair to them when you throw parts and labour at their expense,great vid Dan,love it,btw my wife thinks its strange when iAm in the hot bath watch your vids....
Atleast she's not the one in the hot bath watching his videos and trying to explain it to you.
Because.... that is what i am doing! My husband just got so frustrated by that air ratchet he left the room. Its been 4 months without our 4th gen 4runner PO102 PO113 husband doesnt really ... atleast i dont think he does much troubleshooting. He goes strait for the heart. So he dropped the fuel tank and changed the fuel filter, tested the pump it was ok. New battery cleaned the maf sensor cleared the codes and it didst come back. I know cause i checked. I ran the obd2 code reader and no code when in the on position. Crank no start. Nothing really before this happened. There was a few times fuel was low running on fumes. I remember driving away from the gas station the car didnt have much power. Then going home on another occasion up a bridge didnt seem to have the normal 4.7 v8 power. Then my hubby drove it fishing went to a friends house and no staet. Couldnt evrn jump start it. Towed it home and here we are 4 months later and we are freaking broken. Sucks being poor. Marry 4 money hirls dont do what i did... married4luv.
56 no car, feel freaking hopeless. Scanner Danner must be from Ohio. Me too. I can tell from his accent unfortunately im now in he double ll new orleans. Okay then bye
So glad I found this video my 01 Malibu had no power to the maf sensor after watching this video located the ground found it unplugged and plugged it back it in. Now my car runs smooth and accelerates perfect and shifts great now you guys rock and thanks for saving me a ton of money and headache 👍
+Rick Budrow awesome, glad it helped you. thanks for watching!
Excellent video! I had intermittent maf error code for past three months or so which was getting worse with time. I used to be able to erase the code and it would not appear for a few days. Lately when I erased the code with my Foxwell the engine light stayed on. I tried tracking the fault down but to no avail. Being the cheepy that I am I finally bought a new sensor however nothing changed. I came across your video and decided to troubleshoot a poor ground. Sure enough with the help of the vehicle's manuals I was able to find where the Maf ground wire together with 6 other ground sensor wires on the same lug were connected to the engine. The lug was all corroded and two ground wires to sensors, one of which was the maf ground wire, were totally eaten away. I cleaned everything up and resoldered all the ground wires to the lug and now I no longer get the error code! Pretty sure the problem is solved now but time will tell. Thanks for your very helpful video. Could not have solved the problem without it. You saved me BIG bucks! Thanks again.
Awesome! Glad this helped you!
Very Helpful Video. Thank You.
Daughters Mercury Milan lost engine power, I scanned the ECM and got P0102 and P0113. Doubtful both went bad at the same time I figured another problem like wiring. After your video I found and fixed the ground connection. Now all is well. Problem Solved. Thank You For Taking The Time To Do This Video.
Exactly the same issue I'm searching for. You could say I'm a good woman.a darn good woman. Obd2 codes are PO102 AND PO113
2008 Toyota 4Runner crank no start. It's been 4 months without a vehicle and I'm going crazy. Trying to help my hubby. Watching videos cleaned maf, replaced battery , first off hubby went strait to the fuel pump and filter. Changed the filter, pump was OK.
I'm sorry to hear that. Unfortunately my field is full of them. Too many in my industry have not learned proper diagnostic techniques. The percentage of good diagnostic techs is very low. It is disheartening for the car owners. My advice is once you find a good one, is to stay with him. Give him a chance even if he makes a bad call once in awhile. We cannot be 100% in every "call" we make. Just as a doctor doesn't get it right every time either.
Excellent video - I like how you showed the pin test and adjustment of scope settings for better viewing of pattern.
Thank you! I bought a truck at auction that ran terribly, had major and obvious exhaust leak. After fixing that it still ran lean and threw p0102, p0101, and p1351. Started checking grounds and cleaning them and sure enough, the rear engine block ground wire off the MAF strand was disconnected. It was covered in oily goop so must have been that way for a while, engine now runs normal for its age and no more codes.
Nice find!
Good job.
03 Impala 3.8. Engine code 171. High idle after warmed up. Mechanic said it needed a MAF, same problem, then an IAC, same problem, now he says it's the computer. Seems like another parts changer. So now I'm trying to research the problem myself. Great video!
Ive never seen a computer cause a P0171 code. It is very unlikely that it is the computer. Vacuum leak or fuel psi problem is my guess
Thanks for confirming this. Can't find any vacuum leak yet. Although I did find a TSB about clogged fuel injectors. But why the high idle? 3000 rpm sometimes.
metalmoto good question, sounds like multiple issues maybe. a vacuum leak or low fuel psi will not cause a 3000 rpm idle speed on your car. If it was a MAP engine a vacuum leak generally causes a high idle but a MAF engine will generally idle low. So I do not think your P0171 and high idle are related. Hard to help anymore without seeing the car. I would need data. TPS readings at idle during the high idle issue would help. Also STFT and LTFT numbers at idle and 3000 RPM
Worn out throttle body would cause this. Either get it re-bored or replaced. Cleaning it can make it better or worse. I've seen this code caused by cleaning up a worn out throttle body. I can explain how and why it's caused by the throttle body but it's a long explanation and I don't think anybody is reading.
Ill just leave this here
. Its from a comment a guy had about watching your videos while taking a hot bath. I replied...
Atleast she's not the one in the hot bath watching his videos and trying to explain it to you.
Because.... that is what i am doing! My husband just got so frustrated by that air ratchet he left the room. Its been 4 months without our 4th gen 4runner PO102 PO113 husband doesnt really ... atleast i dont think he does much troubleshooting. He goes strait for the heart. So he dropped the fuel tank and changed the fuel filter, tested the pump it was ok. New battery cleaned the maf sensor cleared the codes and it didst come back. I know cause i checked. I ran the obd2 code reader and no code when in the on position. Crank no start. Nothing really before this happened. There was a few times fuel was low running on fumes. I remember driving away from the gas station the car didnt have much power. Then going home on another occasion up a bridge didnt seem to have the normal 4.7 v8 power. Then my hubby drove it fishing went to a friends house and no start. Actually crank no start.. (the dreaded) Couldnt even jump start it. Towed it home and here we are 4 months later and we are freaking married4luv. ...
56 no car, feel freaking hopeless. Scanner Danner must be from Ohio. Me too. I can tell from his accent unfortunately im now in he double ll new orleans. Okay then bye. Also changed the start plugs. Noticed a oil lead from valve cover bolts? He said they were really loose. So there is some oil leakage that's covered some things. He says it's normal... me ...
It's a computer.
get me some voltage measurements on the MAF with the key on and engine off and I can help. On your Toyota, it is an analog signal, not digital like this GM, so it is even easier to measure
@@ScannerDanner Hey, sorry for the late reply. I've been watching videos trying to find out how to get the voltage on the MAF sensor. I started watching your masterclass on that. Then my husband's brother came by and they were convinced it was a crankshaft sensor but I don't want to just throw Parts at it do you have any videos that would point me in that direction do you have a link that would be great he's got a voltmeter.
@@ScannerDanner we are on our way out now. I do have a live reading when I ran the obd2 the maf was 1.50
IaT c° 35
Baro 101
eq rat 11
Eat113
Be right back with a voltage reading and I'm going to check the obd2 scanner a little better.
Thanks again.
Scannerdanner is the manner. You sir, are a diagnostician. More people need to follow this! Not shot gunning parts
good question. what you have to remember is this circuit is monitored for frequency so a circuit low code means low frequency not low voltage. hope that makes sense
What sucks is not everyone has a scoop....but love the video and the tech talk
Hello there ScannerDanner, and you're so right. There really are a lot of parts changer out there. I sometimes play in left field, lol . But I do appreciate your videos. Thanks a million.
Yes ! I took it for a drive this evening to "re- enact" the DTC trigger, at 100 km/h, the check engine indicator came up on the instrument panel & I had the Bosch scan tool plugged in.
I got the P0332 code to show up on the scanner & that's with all the air leaks fixed,it ended up being the case that I have to replace the rear knock sensor on the LS1 engine.
The one I currently have fitted comes from Hong Kong so no more of them,I'll pay about $88 AUD for a good fuel miser branded one.
I know the loom is o.k. because I soldered new connectors onto the loom & both sensors read at 100 k ohms.
The rear sensor has the case of triggering a DTC due to a low output signal.
no problem and I'm glad you found the video helpful thank you for the comment
Great advice I’ve been chasing the same problem on a 02 Yukon 6.0 and clearly explained thanks a bunch
Yup, The true way of fixing problems.. Diagnose THEM FIRST!
Thanks again for a great video Paul.
So True,About "Parts Changers"!!!!!!!!!!!!!! The easy way Put,and still no fix,and The cust Pays!!!!!!!!!!!! Thats why Its easier to BE HONEST!!!!!!!!!! Word of Mouth Goes faster than the Internet,!!!!!!!!! Nice Job,,,,,,,Jack
another good video,thanks; that's why I always measure the input voltage against the ground wire/terminal right *ON* the sensor,i don't care about the ground elsewhere.
Of course its more technical than a check engine light! Nice going Scanner Danner!
I see all the comments about parts changers and agree totally. I think the problem is that auto repair shops would rather take a risk and throw the most likely part at it, instead of doing these sorts of tests to really know they are throwing the right part at it. I even wonder how common it is for a repair shop to have a professional scanner like a Verus or Vantage Pro.
There's no way that I would be on that air ratchet. When this electric cowboy is giving golden info. I can learn how to put a bolt in threads with a air ratchet later. I want to learn what scanner has to teach.
Bolt boys...😒
Excellent diagnosis! I had a similar issue with a Monte Carlo. Customer was irate as had thrown parts at the car for a P0102/420. As you can imagine not cheap. I did some checks, and it was the charging system. Alternator was bad.
Thank you for this video. I was seriously about to buy a new mass airflow sensor. Your are a lifesaver.
Its not many of you out there today. Good job!
Thank you so much for your expertise and advice
u don't need a Verus to do what i did in this video. it could have been done with a multimeter and a basic scantool. although to see the actual waveform that i showed at the end u would need a scope for that. look into the picoscope. or maybe the vantage pro. the vantage pro has the advantage of an awesome database and the picoscope has the advantage of just simply being a much better scope.
depends on the current flow of the circuit. Higher current circuits will have higher ground voltage levels. Computer and sensor grounds should be less than 100 mv
Thank you sir, very good explanation on troubleshooting
this is a twelve volt supply. the 5v is the signal circuit. if you have my eBook refer to Section 2 for this MAF circuit design. sorry to much to type here
Fantastic !! This is why you need proper training and a good trainer like you.
Very thoroughly explained. Thanks mate.
Thats really cool. I wish I knew somebody like you to troubleshoot my car.
I think the key to being good at anything is to like what you're doing :-)
Yeah :)
I can't handle all of this praise. I'm really not that good I just like what I do :-)
Great job! P.S. That air ratchet was very annoying.
Very in-depth.
Very professional work. Great job
thank you very much
can't argue with that
that is correct but it would depend on where in the harness the sensor ground wire was corroded. if it was in the last leg on its way to the computer yes it would affect all sensors. if it was on an individual branch it would only affect everything on that branch
Sir you are having a good video 👌
I got lot of knowledge and experience and helping
See some people's don't like problem is those assehole don't understand
We love you Mr Paul
Nice, I have to check on mine truck ,because when the scanner is connected, I saw the maf sensor wont move at all ,is at 0.20lb,I don't notice anything if is plugged or unplugged.
Oh my brother, thank you so much for posting this demonstration of how to look for when you have a related problem,my car was jerking and throw me code 102, I watch your video and after that I star troubleshooting, and I fucking found the battery bracket loose and making contact with the positive of my battery, again thank you much,like and subscribe 👍👍👍
Yes a faulty MAF could cause your symptoms and the P0102 and P0171 codes. Not sure about the P0131 off hand.
Once again, you're the best automotive electrical troubleshooter out there, and if I was still in the 'burgh, I'd be signing up for your class. Now that i am done sucking up, I know the MAFs are measured in terms of Hertz/kHz, which means something happens every second. But what? How is airflow translated to a frequency unit of measure ?
What are floating grounds in a computer sensor and how are they tested compared to other grounds ? Thank you friend
How many Ground splice connectors typically does a car have. I have a 2000 Lumina and was wondering where they were located but cant find a diagram anywhere. I also have a P0102 code right now on the car which is also a 3100. Going to test everything tomorrow with my multimeter
Nice video , excellent find , saved the part , 5👍🏻up..
I learned something new today! Thanks for the video, Dan!
Good video thanks
I have a 2001 Chevy Malibu that just cut off on me while driving. I was told a few things and none of them have been right so far. Now I have a friend who asked to see what's up with the car and when we tried to turn her on we had smoke rising from under the car somewhere. My question is could that smoke be coming from the connection terminals to the battery or the starter. I'm really not to big on working on cars nor fixing them but your help and guidance would greatly be needed
Excellent work!!!!!!
LQ4 /4L80e
Code P0102 low voltage maf sensor
I have ground,12v, 5v. Across 3 Maf sensors,1 that is new. Cleaned TB front and back. New tps and iac. Have not found any vac leaks and tried 2 different intake set ups.
Idle is 650, surges/lowers when put in reverse.
Hesitation/bogs if I throttle to fast.
No other codes
Stumped.
I'm assuming this is a GM? What is the frequency of the MAF signal with the engine running? Should be about 2khz at idle.
The 5v wire is your signal wire and it should be a pulsed signal
Yes, for the inputs sensors
I have a 04 Chevy impala Maf has code p0102...will the crake sensor cause this.
Thank you
Good catch / find once again!
Thank you 🙏. My freaking ground cable was loose
Sweet
Well done ... I have a question... Got a 99 chevy suburban within the
past 5 years it slowly A- starting running good then rough and now very
rough, B -gas gauge fluttered a little, got worse and worse to now full
on flutter on "Full" and C random shit is shorting out once something is
fixed ... for instance ...AC dashboard switch (medium low) grey wire
burned out... once that was fixed the 3rd or Medium high burned out wire
... once that was fixed my 4wd actuator started shorting out... then
battery drained...then rear driver side tail light mother board burned
out (bulbs were black and mother board smelled like burned plastic)...
then alternator dies, battery again, window motor driver side burned out
(melted plastic) ...Blower motor wire burned ...etc ... ALL right after
another ...all electrical and it's running very rough now, (idle is
rough but runs good on highway), random misfires codes po300 came on
today while trying to fix barn door lock then went off and came back
intermittently, abs light came on last week as well and gas gauge
flutters (need to look close-flutters so quick) at full constantly. One
mechanic said it was engine rebuild, another said fuel pump and another
said Fuel injector(fuel spider) ... I believe its just a bad ground
somewhere... possibly in the back near the gas tank??? b/c my driver
side rear defroster in window do not work (passenger side does) and also
I replaced my driver side rear tail light mother board three times
already(including last week)...once I replaced it the ABS light came
on... I jiggled the copper connectors for my rear barn door (driver side
door) door doesnt have wired connectors, instead it has those copper
pins or connectors sticking out... while doing this with a friend we
noticed gas gauge would stop fluttering and go down to almost empty fuel
gauge (which I think is where it is at) ... that's the first time I saw
the fuel gauge NOT flicker in 6 years! and misfire codes disappeared as
well ... any idea? Am I crazy or what ... also- I sprayed electrical
cleaner on ground under driver side rear (strapped on to fuel line
connected to gas tank and my friend put his hand on it and swears he
felt a tiny shock ... I did it a minute later and didnt feel anything...
any ideas? I'm desperate but determined and also, everything that goes
wrong electrically (in case I havent made it clear) seems to go right
after the other- which is why I think it's a grounding issue
you have more issues than I can help with here. Can you post to my forum?
www.scannerdanner.com/forum#/general-repair-questions/
Thankyou . You where a huge help . Will thumbs up and subscribe .
Thanks Stephen!
Since I don't have the equipment you have, can this test be done with a voltmeter?
Very good video
Watched a lot of your videos. they're a great help. But ran into something that has not been mentioned anywhere. My sons 1998 Pontiac Transport 3.4 l. In this you talk about a 5 volt square wave and its a pull down circuit. I ran done every thing as stated , 3 wire connector as you show there. id the three wires. we have three codes of P0102,P0300, P0440. starts ok when cold but warms runs bad, and stalls if you let it, hard to restart. all went ok till the signal wire to either battery ground or sensor ground at plug with a volt meter. with motor running instead of 1 volt and ramps with rpm increase it reads a 4.45 volt regardless of rpm and or either ground. Cant seem to find anything on it. Was told that MAF was bad and replaced it to have same issues. Thanks for any help.
sounds like mine 3800 series 2
Very helpful. Thank you very much. So, where would I put my setting for volt meter? At home diagnostic.
Thanks for your advice!!!!!
Great job my dear
Thanks for the video very helpful I have a 97 chevy truck with a p0102 code so when I check the wire with a light tester the truck shut off right away could it be the same as the video ( 2000 chevy Malibu MAF ground problem )
Same year truck, Same problem, Trying it tomorrow!
yea i had the same issue on my 2003 impala. but couldn't find the ground break. so i did a direct single wire hookup to the sensor plug and to a bolt to the engine block and all working again.
Hi Paul Is the trouble code Said single Circuit low. Doesn't that mean Signal shorted to ground or open in the Circuit? If it's a bad ground Shouldn't that mean Signal circuit Highd? Great work and thanks a lot, Jeff
It could be either! The variable is if there is a bias voltage on that circuit.
good job! wish I had you here.
thank you for this video!!!
no it does not apply to nissan and toyota they are analog type mass air flow sensors. the only time I apply the terms pull ups and pull down are with digital signals.
great video. thanks for posting!
What could cause higher than normal Maf reading on idle?thank you. Example 3.0 reading over 7 gps idle
I have some case studies on this (Subaru I think), where a dirty MAF can overestimate airflow at idle speeds
what trouble code do you have
Great video, you know your shit. Applause!
Got 99 buick regal ls....stutters when accelerating. Changed spark plugs and wires....whoever had the car before tore the boot for the #4 plug and wrapped tape around it so it super coroded and broke off. That stopped the misfire, but i also had a p0102 voltage high code. Cleaned the maf sensor and it worked fine for a while that day then the code came back. Should i just change it or do a little more digging.
watch this ruclips.net/video/p2QLxxstRn8/видео.html
ruclips.net/video/E8sBg7kMbOw/видео.html
I replaced the MAF on my 2009 enclave as well as the purge valve AND the ECM ($800+) and I am STILL getting code P0104 (MAF sensor), and sometimes P0201 (ECM), C0104 (unknown) and P0104 (unknown). Any suggestions?
You said pcm send 5 volt to the sensor , sensor pull to the ground .why we have battery voltage on power wire not 5 volt?
Please 🙏 answer my question
Because a MAF sensor is not a simple sensor at all! It is a miniature module that needs a power and ground to work (to turn on). Make sense?
what if I have a 03 honda accord 2.4 with a P0102 Maf voltage low, no matter how much time I spend looking for a maf sensor can' find one neither to test not to check 🙄
lol on the sucking up part. don't you mean how is frequency converted to air flow? it would be the same way every other sensor is converted the engineers write in a ROM lookup table what the value is in there you have it. wish I knew more about that part of the industry. I have to go back to school for electronic engineering
Gee what a surprise, a GM product with an electrical problem...
Lmao right
Great video Paul as always, I see too many 'parts fitters' which annoys me as a little bit of thinking and checking will usually fnd the problem. Just to confirm then.. 100mv and below is considered a good earth with the circuit loaded ie key on with current flowing?
yes. even a regular voltmeter would have caught this one
My 1999 c1500 Suburban with 5.7 vortec has a 4 codes going off for maf and crank sensor think it could be a ground? I put new crank sensor in and checked connections look good
Please post this to my forum. It is free to join.
www.scannerdanner.com/forum.html
I have over 17K members world-wide and I also have paid moderators who are there to help me help you guys!
Thank you for understanding. Hope to see you on the forum!
Great Video Paul, just a quick note, if sensor ground is shared across multiple sensor , and if ground is corroded it would impact all sensor not just that sensor, is that right. since it is single wire , impact on one place would impact rest of the points as well.
Is this applied to a 1996 buick century that has the same engine
Thanks bro! How is your new job treating you?
Alex Jones of auto diagnostic analysis. 😆
no. use the engines airflow to test it
P0131 - GM = HO2S Circuit Low Input Conditions
Location
Bank 1 Sensor 1
Cause
Engine running in closed loop, then the PCM detected that the HO2S-11 signal that was less than 250 mv (less than 97 mv on VIN 1 & K engines), condition met for 2-4 minutes.
I got issues with my 97 Malibu...can you put that thermostat in the wrong way..
+lilStevieWonder ? not sure man sorry
i can't help without a code. if it is still setting a maf code then watch my two part GM maf sensor testing videos
SCANNERDANNER, can you please make a youtube video explain the differences between a MAF and MAP, they seem like the same thing to me and i don't understand the differences between a MAF and MAP. What car components , car modules, car sensors would a car technician measure the frequency, PWM, duty cycle, can you please give a bunch of examples of when measuring the frequency, PWM, duty cycle, for what car modules and car sensors?
Hello. I have the same code on my astro van 96. I already replace a new maf sensor. But the code still showing on the scanner. Any ideas to my problem??