Passat MAF, problems with the MAF sensor, Mass Air Flow meter

RBK la Muntele Rosu
Last days, RBK ( Rebe ), my old faithful Volkswagen Passat TDIRBK la Enisala  show some signs of weakness. Symptoms: Suddenly loss of power. Car, very lasy! The car didn’t accelerate as it usually does and with the gas at full, yon need a century to go up at 100 – 110 km/h. ( 62 mph ) The engine go up to 2000 rpm then hold around there, and no further.
Ok, first think, maybe it was the gas filter or, god, hope not, the turbo is broke or jam.
But normally the turbo didn’t broke easily at this cars, and the filter was new, so let’s check the sensors chain. I wrote this small tutorial with images to teach step by step maf replace.

VW Passat MAF location locatie
With vagcom and a cable it was easy to diagnosticate, but I have not those things. (Today i have! I made for my self a vag-com cable. )
So without proper equipment, let’s try step by step. Take some Spice from Dune and with the help of The Force i start with the MAF Sensor. His location as show in pictures, is just after the air filter.  So I chose the easiest way to test your maf.
The very easy way to diagnosticate this sensor is to pull out the just the cables and test the car on VW Passat MAF location locatiethe road. If the car run in the same way, or even better, you can be sure, the MAF sensor is gone. That’s exactly what I did and the car accelerate better without the MAF connected.
Hurray, is not the turbo! The MAF is broke.
The MAF, Mass Air Flow meter is the sensor who indicates to the ECU (car computer)  the air mass who flow inside the engine.

VW Passat MAF sensor senzor close-up
I take it out, and try cleaning. Usually if is not completely burn out, a good cleaning with isopropylic alchool can do the job.
But not ever think to touch the sensor itself with something, like paper or a stick with cotton. Just alchool or clear, very pure contact spray for electronics.
Don’t spray directly on the sensor. The power of the spray jet can damage it. The best way is to immerse the sensor part in isopropilic alcohol and let it about 30min with gently shake from time to time. Please, DO NOT open the sensor, do the cleaning with the sensor as it is, unless you have nothing to lose and you are prepare for a new one!!
VW Passat MAF sensor senzor close-up
If this treatment do not restore the MAF sensor,
VW Passat MAF sensor senzor close-up
maybe is time to buy a new one. If you have BOSH, you can buy also a Pierburg one, is (at least here) much more cheaper and work great.
On my old BOSH MAF I do a autopsy and I put the pictures here and a repair tutorial. Remember this sensor is burn out, do not open yours.
The MAF sensor work by heating a small filament at a certain temperature. With the air blowing over, the temperature drops. So the filament need more electricity to rise up the temperature. The ECU measure the power needed to keep the temperature, and estimates the mass of the intake air.

Pierburg, Bosh and Vader
MAF defects can show because the dust from the air, or more often from microscopic drops of oil, especially if you have sport air filter, with oil.So, the conclusion: if you have Volkswagen Passat TDI, or Skoda TDI, or anything TDI with MAF sensor, if your car lacks power is lasy, do not panic.
First, disconnect the MAF and test the car. If the car runs nor badly but the same or even better, then you know, is most probably the MAF.


112 comentarii

Din categoria Auto, Uncategorized

112 răspunsuri la „Passat MAF, problems with the MAF sensor, Mass Air Flow meter

  1. If you have questions or problems about your car, Volkswagen Passat or something similar like Skoda, Seat, Audi, feel free to ask! Good Luck!

    • wes

      Hey u have a 98 Passat 1.8t auto with trip. It’s starting low and stalls out unless I give it gas and then it sputters and tries to die and you have a gas type smell and a little smoke when you start it

  2. andrey

    sall am o problema cu masina se opreste mereu cand o scot din sarcina sau pun frana un vw passat 96 benzina si gas daca putety ajutatima si pe mn mersi mult

  3. Hello „The vale”! I’m writing from Portugal and I need your help if you can help me.. I own a Volkswagen Passat 1.9 TDI year 2004. Yesterday I was with my mechanic changing the oil and filter and I saw a big big amount of oil at the turbo/intercooler side.. I know that my car has already 200.000kms but I want to solve this..Is this problems with the turbo?? What I have to change to solve this problem? As I said there’s a lot of oil below the car in the turbo/intercooler area..Your help woul be appreciated..Thank you. From Portugal. Luis Filipe.

  4. Hello Luis! Sorry for the delay but I was in hollyday, in Greece.
    Lucky You, nice country Portugal!
    The problem you describe, is not big truble. Is quite common at old cars over 100.000km. These are the oil vapors from turbo and some pass the intercooler and cumulate there down over the time. You can just wash this oil out and look how long it takes to come again. Absolutely no problem with turbo if your car runs ok and no problem if you don’t see oil under the car, on the road or in the garrage where you keep the car.
    Happy driving!

  5. matt,passat


    Took your advice on the maf sensor unplugged it and run it and yes it went better (no stuttering when i accelerate). So i cleaned the sensor first of all it ran great but then second run out went back to stuttering and not accelerating well. So thought i would buy a new one £70 lighter and it hasnt made a blind bit of difference. The car is a 2003 VW Passat Tdi. If any one could help it would be much appreciated. A couple of people have had suggestions but i dont really want to be spending out any more untill i have a clearer picture.

    Many thanks


  6. John


    I’ve got the same problem as Matt. I replaced the MAF, but the lack of power in second and third gear remains.

    Any help would be greatly appreciated.

  7. Hi John,
    for testing the MAF is easy, just unplug the wires from it, and run the car like that.
    If is going better is the MAF. But take care, maybe is not the MAF itself, but the wires going to, it is a common mistake to blame the MAF senssor when the wires or connections are bad. You should check that too.
    Gook luck and many miles with your car!

  8. Steve, passat

    Hi Matt,
    I had the same symptoms initially started with periodic loss of power and a key off and on would sometimes remedy the problem but the turbo had a long lag from stand still. Eventually the turbo would not kick in so I had a total loss of power, Changed the Maf but no improvement and in the end put the car on a diagnostics that showed the problem to be the turbo manifold flap control valve at a cost of £55 the problem was resolved.

  9. Hi Steve!
    At the car, the sudently lack, loss of power and which can be remediate with an engine restart, or with the key off and on, indicate a Limp Mode induced by the bord computer, the ECU, when he detected an error and LIMP MODE is more dramatic than the power loss from the MAF.
    Normally, when malfunctioning, the MAF do not induce Limp Mode. The lack of power is constant regardless of restart, and if you disconnect the defective MAF, the car can go better. This indicates with no doubt that the MAF is the problem.
    Have a nice weekend!

  10. Dickson

    Thanks Vale for the good work.
    I will also test my MAF and see.

  11. Hi Dickson! 🙂
    I’m happy to help!
    Hope your car will run ok.
    Also, if you need the info, here I wrote a tutorial, step by step with pictures, about changing the filters at VW Passat, air, oil, diesel, pollen. Enghlish info is in blue.

  12. Pawel

    I have ’98 1.8T automatic transmission Passat, and I have few problems.
    1. First i noticed that Passat lost power. It accelerates very very slowly, if under small hill it is horrible. Is it problem with turbo? How to solve this?
    2. Two days ago I went to school. Was ok (except lack of power). But when i turned it on when wanted go back, it started shaking a little. When i started going it looked like it has problem with air. When I pushed acceleration pedal it started sucking air. When I released pedal this sucking was gone. And that is all the time when i press pedal it is sucking air like under pressure. On neutreal it is almost not visible. I checked, in my oppinion it is problem in this system close to passanger head lamp where air filter is. But what exacly I have no idea.
    Thanks for all your help.

  13. Hi Pawel!
    So you hear a noise like air under pressure? The most probable it-s a hose, a tube with a crack or a hole or maybe loose.
    Before the hole in the tube was small so you you lose presure without noise, but now is bigger.
    I think you must check first the big hose (tube ) wich come from turbo. Better to look from under the car.
    After, check all the vaccum tubes, but very carefuly, even a small hole cand make your engine run bad.
    Hope to help and have a nice weekend!

  14. Ribal

    Dear Vale,
    I have a 1994 golf vr6,recently i faced an acceleration problem,especially dring the second gear and some times it stalls for about 2 seconds and then it runs normally,what do u expect to be the problem.
    Thanks for your support

  15. Hi Ribal!
    I suspect some filters who don’t allow enough fuel needed by the engine for the quick jump in rpm and power.
    So the engine runs poor in fuel for 2-3 seconds.
    Hope this help and keep in touch.

  16. Garrett

    I have been having problems with the MAF in my 2004 VW 1.9 TDI Passat. The problem first occurred during a long journey when the car started losing power. At first I assumed that I had got dirty diesel and after a day or two the problem seemed to subside. The next week I went on another long journey and this time the ‘emissions workshop’ warning light came on and the car was almost un-driveable. The next day it seemed ok again but the light stayed on.

    I brought the car to a garage and they checked the computer, which immediately said that the MAF was at fault. This was replaced but the car still didn’t feel right, it was better, but still slow off the mark. 2 days later the warning light was back on and the car was back to the garage.

    I have now had the MAF replaced 4 times by the same garage and the problem still persists. After changing the filter for the 4th time everything seemed fine, for about 10 minutes, until the turbo seemed to fail completely. I am now in the situation where the car seems ok up to about 2000 RPM but then starts pulling back.

    I have no doubt that the garage will replace the filter again but at this stage I really just want it fixed and am starting to be embarrassed arriving into the garage every day with the same fault. Any advice would be well appreciated.


  17. Hi Garret!
    Sorry for my late answer but I was in hollyday in Turkey. 🙂
    Emission workshop warning light is related also to the oxigen sensor who can fail or to the EGR.
    But, if the guys at the garage is verry very sure that the MAF is to blame, I think they shoud check the electrical wires and contacts. The fault can be there, between the ECU (computer) and the MAF.
    Also, maybe you must see another garrage 🙂
    Hope to help, Valentin

  18. Ribal

    Occe again its me 🙂 well,all filters are now new,and still facing the same problem, another hint i can give is that when its neutral and pushing the throttle at a constant level, for example (3000 RPM) at the same throttle, the rpm would go down for about 2000 rpm then up and same thing repeating every 5 seconds…could it be the MAF ??
    thank you

  19. Hi Ribal! 🙂
    Well, this is interesting! Let me think and also ask some friends. I don’t think the MAF is the problem, but…. who knows. You can easy check the this by disconnecting the MAF and give a try. I still suspect some lack of fuel or maybe, bubles of air in the fuel pipes.
    Anyway I will ask an come back. 🙂 Until then, Have a nice Weekend!

  20. Ribal

    good day,
    Just one more info, is that i realized that the car stall usually after bieng driven for about 20 mins and not before, i removd the MAF wire,but it went worse,so as u said ,it doesnt seem the MAF is the problem, also the ECU doesnt shows any error on the scanner..but as i read on some sites, could it be the coil pack??
    thank you.

  21. Hi Ribal! 🙂
    Yes, it can be the coil pack, but usualy that goes with an error code about missfire. Anyway, you can check the bad coil by measure the resitance and also, when the engine start vibrating or stall, when the problem begin, try pull out one by one the coil and see if it get worse. If at some coil the engine not get worse, it is a bad coil.
    But I still ask here and there about the problem, and I will be back 🙂

  22. Ribal

    hi again man,
    as if its a mystery that we need to slove 🙂 i guess its related to something that doesnt function well when its hot maybe, im assuming that, because the problem takes place only when driving throuh a montain raod and not in the city,recently as usual facing the same probelm of stalling,also when i stoped due to trafic and again to move on,i pressed the gas throttle but…no response the car didnt move if no throttle is found,the problem last for about 8 seconds and then moved on…
    sorry for taking from you time, and thanks for your help 🙂

  23. Hi Ribal! 🙂
    Well, this send us to some electrical contact 75%.
    Something similar happend to me 2 years ago, after a heavy rain. Total no throttle!! At home I found water in area near the ECU. After take the water out and open the ECU box and let it dry one night, no more problems.

    I guess, check the chain of sensors for some bad wiring and the ECU links….
    Also some garlic, silver bullets and holy water can’t hurt 🙂
    Some malfunctions require an exorcist 🙂
    Keep me in touch and have a wonderful weekend!

  24. william Zemanek

    I am in need of changing my MAF on my 2004 Passat, but I am having problems finding it. Is there anywhere to find a diagrahm that shows how to locate it and replace it?

  25. Hi Zemanek!

    The MAF is located, must be somwere after the Air Filter and before the turbo. I guess the pictures above is different, because my VW Passat is 2001.
    Good Luck!

  26. Randeep

    Hi Vale,

    I have a Passat tdi 1.9 Diesel Automatic. My car was very weak and does not accelerate as it should do. I took the MAF off like it shows in the pictures and the car has definately gone faster.

    So does this mean that I need a new MAF sensor? I have booked it with the garage for next week. Till then can I drive my car with the MAF sensor on or would it cause any damage? Please advice.


  27. Hi Randep!
    Yes, in this case, chances are 95% that the MAF is bad. But also can be a bad electrical wire shorted or a bad connection somewhere.
    No problem with the car driving like that. The ECU take the default values. But I think, with a little attention, you can change the MAF yourself in 10 minutes, no need a garage. Also you can try cleaning it, the MAF sensor, but the results are rarely good, but anyway no harm trying.
    Best whishes and have a nice weekend.

  28. Randeep

    Thank you for the quick reply Vale. Yeah I have ordered the MAF bcoz i took it out and it looked burnt out. I will give it a go myself with the help of my frend. Thanks for your help and will let u know if replcing MAF fixed the issue or not.


  29. marty

    hi all, my 1998 passat 1.9tdi has lost most its power, tried disconnecting maf but no difference, pluged n fault code reader and came up with „01262 solenoid valve for boost pressure control N75, open or short circuit” would this be a faulty N75 valve or wiring prob ? many thanks for any help marty

  30. Hi Marty! 🙂
    First, if when you disconnect the MAF, there is no difference, that means the MAF do not work verry good, normally if the MAF is OK, the car should get worse whitout it.
    Second: about N75, I think is a wiring problem, (short or oxide) but always you can check the solenoid with ohmmeter to see if it’s good or burned.
    PS: do not try to measure the voltage, it work in small quick pulses.

  31. Scott

    I recently got a Check Engine Light (CEL) and took it to an auto parts store for the diagnostic and it said „Engine is too Lean.” I’m guessing it’s either getting too much air, or not enough fuel. Would the best bet to check the MAF first or the fuel filter?


  32. Hi Scott!
    Yes, a dirty MAF sensor could cause this problem. with engine running lean.
    You can try cleaning the MAF sensor, but VERRY carefouly!
    Good Luck!

  33. Dan Cheloo

    Salut vale.
    nu ai mai intrat de mult rau in VW – CLUB.
    ce e cu tine?…te-ai suparat pe noi?
    care mai e viatza?…
    ce ai facut vara asta?
    pe la MARE a i fost?

  34. Salut Dane!
    Mi-am uitat parola la VW!
    Azi plec sa escaladez Mont Blanc sa-mi tii pumnii!
    Vorbim cand ma intorc!

  35. Aimee

    Hi there! I have a 2003 V6 Passat. The check engine light came on last weekend, but the car displayed no symptoms of a problem. I brought it in to VW; they diagnosed the problem as a bad MAF. I had it replaced, but when I picked up the car and attempted to drive away it started lurching and shaking. VW checked the car again and saw no problem, so I left. The check engine light came back on an hour later and the lurching (shaking) continued. I brought it back to VW the next day. They told me there is a leak someplace…but that they cannot locate it. I needed the car for the weekend so I took it home. The car is barely drivable. It chugs, lurches, shakes, and is very lazy. I brought it back to VW today…and they STILL cannot find the problem. The car was operating perfectly before I brought it in. Do you have any ideas on what’s going on here?? I would appreciate your thoughts!!!

  36. George

    Hi Vale,

    Had an engine replacement due to a timing belt break. Mechanic installed new Engine. When he gave the car back check engine light was on along with anti slip light. He said it was ok to drive and no need to replace it unless the light being on bothered me. I also took it back the next day as i noticed a hard shift when going from Park to Drive. He said that it wasn’t anything serious and that he would research it. Car drove fine even with light on, however after a few months it started making noise and was leaking all transmission oil. Had it towed back to him and he said that the transmission had failed and needed a new one. Couldn’t understand how that was possible. He installed a used transmission and again it was hard shifting even worse than the original transmission. He decided to now take it to volkswagen and they did a diagnostic and before doing anything, they replaced the MAF. and the hard shift went away. I’ve been so frustrated. Can an unplugged MAF damage a transmission? Wonderig if he had done that the first time the original Transmission wouldn’t have failed?
    looking forward to your thoughts. cheers.

  37. Hi George!
    I am sorry to hear about what is happen.
    No way can a damaged MAF or even a unplugged MAF damage a transmission.
    Normaly, it shoud not even turn warning lights on.
    This two lights on, antislip and check engine light worn about something very serious happen in / with the engine or transmission. The mechanic should at once put the car to a computer test for scanning and diagnostic codes, not let you drive like that.
    Really you shoud change this mechanic.
    Hope to hear good news!

  38. salih

    I own a passat 1998 1.9tdi … I have several problems to report 😀 hah … first the MAF malfunction that’s obvious and easy fixable ( replaceable ) i only need to buy a new one so thanks for the advice from above :D… also the temperature meter in the cockpit usually isn’t working, sometimes it just jumps to 90 degrees Celsius ( so works normally ) but that’s rarely, its nothing dangerous i hope but it nerves (i’m not sure how to fix that… the third problem is with the brakes … when i am braking constantly end even i can feel the front right brake, brake unevenly it could be a problem with the ABS … so help is needed

    thanks in advance

  39. salih

    I’ve been reading around … and found that the temperature gauge is malfunctioning because the Engine Coolant Temperature (ECT) Sensor isn’t working … so it would be nice if someone could explain the position of that ECT, post a picture or something … for the passat of course

  40. Hi Salih!
    For the brakes problem, it could be not necessarily the ABS, but it could be the brake disk or plates. You should look at them. Also, chek the wires to the ABS sensor.
    I am not sure for your VW Passat coolant sensor location, but look down under the fuel pump, behind the engine. You should see some silver insulation covering wires and the sensor down, near the exhaust pipe.
    Maybe this can help you:

  41. MARK

    Hi i have just purchased a vw passat 1998 1.8 auto 20v sport and was shocked by the fuel consumption the computer says its doing an average 20 mpg, can you tell me if this is normal for this car or if the maf sensor could be at fault.

    Best Regards


  42. Hi Mark!
    No, that’s not normal. Normal fuel consumptin at your VW Passat it is about 30-36 mpg
    But when engine is cold and if your driving style is very sportive fuel consumption can go higher but not for average, unless you drive constant at 180km/h. 🙂
    The MAF Sensor can give erroneous information, and you shoud check with a vag-com cable and a computer.
    Hope this help!

  43. Enigma

    Hi there,
    I’ve bought a year 2000 Passat TDi two weeks ago from my local auction which has just over 100k on the clock.
    its drives smoothly and turbo kicks in when driving at lower speeds on 1st 2nd & 3rd gear. however when driving on 4th and 5th dear it really struggles to accelerate. I drove on the motorway & it stays on at 70-80m on 5th gear. there’s no noticeble smoke or anything.
    my mate said first try removing the air filter and test drive to see any difference. I haven’t done that yet.
    Would like your expert advice on this.
    really appreciated.

  44. Hi Enigma!
    Congratulations for your car.
    Your friend may have right, it coud be a dirty air filter. But never run whitout air filtrer, buy a new one, it’ s cheap.

    But also a old / dirty MAF sensor or a cloggy itake pipe after the EGR valve or a dirty / cloggy turbo (especialy if the first owner was an old man who drive slow) can lead to this simptoms.
    Hope this help.

  45. salih

    Im here again … 😀

    I changed the maf sensor. Bought an expensive bosch part and no change … with it or without it it runs the same … i cant see any damage on the wires connecting to it…

    (so it isnt working at all … it is a maf problem but not exactly on the sensor itself … somewhere else … im planing on finding a wrecked passat and taking its cables 😀 for a first try and of course I was hoping that you could tell me what else could be the reason for the maf not reacting at all so I can work on it)

    I bought the car with that problem so i can only say that it isnt going from 0-100kmh in 13 sec and that it cant go over 130kmh and it should go over 180kmh to be exact 183kmh 😀 😀 😀 .

    RPM-s wont go over 3500 … it just stops there

    and the local workshops are not trusted … id prefer to solve this one on my own

    and thanks for the advice from above 😉

  46. salih

    I will also try with that EGR valve and its pipping 😀

    Its nice to have someone who actually wants to share his knowledge thats rare

    Im realy thankful for your advice … 🙂

    sorry for my bad english

  47. Hi Salih 🙂
    Nice to see you back and sorry for your car problems.
    You have right, workshops can not be trusted.
    Can you have acces at a vagcom cable to scan yorself for errors? It is cheap, from ebay, just 3 – 4 USD
    What about your temperature sensor? Maybe it is electrical problem togheter with MAF Sensor also?

  48. Enigma

    Hi Vale,
    Having tried changing the air filter with no luck, I decided to go to reputed garage in the city. First they tried replacing MAF and said it wasn’t faulty. Then replaced the MAP Sensor (Drawer pressure sensor ) which seems to have resolved the power problem. The bill was £220, but I’m glad its all sorted now 🙂
    Now I know it is a simple fix if you know what you are doing. I should get hold of vagcom cable and try learing a bit on this area myself.
    Thanks for your advice. 😉

  49. Emilijan

    Hi Vale,

    I own a 2004 VW Passat 1.9 TDI 130hp 5 speed tiptronic and it has 190 000 km. I’ve recently had a trip and that was 95% on the freeway/major road. There were 4 people in the car with luggage. When I did the fuel consumption calculation it came out 9.4 l/100km (30 mpg (British)). I think this is very high fuel consumption so I thought I’d ask you if have any idea or suggestion what should I be checking.

    Thank You

  50. redgirl

    hi Vale
    I have a passat tdi 1.9 automatic y reg and I have a total loss of power going up hills. I have read your advice about the maf and am going to try this but I have also had out my ecu and there are corroded wires so i guess it could be related. What colour are the wires that connect to the maf?? as I have orange and brown wires that have seperated from the the ecu – could it be these??
    Please help!!

  51. Hi Enigma, Emilijan and Redgirl. 🙂
    Ouch, Enigma! I am sorry! They got you! It was very expensive! Realy a 3.5usd vagcom cable it’s useful around home 🙂

    Emilijan – You have right, it’s a very high fuel consumption. Normally in such condition your VW Passat shoud take around 7.5 l/100km or 31.3mpg
    But also it depends on how fast and furious 🙂 you drive. You shoud check the pressure in tires, the air filter and if those are ok, the fuel temperature sensor and coolant temperature sensor, and also give a try with an Injector cleaner. Last resort, the injection timings.

    Hi Redgirl – Yes the wires could be from MAF. But also from a lot of other sensors lor electrovalves like N75. My MAF wires are orange and green. Try the trick with disconnected MAF and if you are lucky this is the problem.

  52. Emilijan

    Hi Vale,

    Thank you very much for the advices, I will check the things and I will post if I find anything.

  53. Enigma

    Hi Vale,
    Two other small problems have started now.
    1. RPM stays at 1 even when the car is idle, i think it started since they fix the MAF issue. do you think I can fix it myself or take it back to the garage for them to fix it ?

    2. there is a strange ticking noise coming from inside the dashboard (its very random, sometimes just one or two ticks and sometimes it ticks like 10-12 times continuously. I think this started to happen since got the full service done two weeks back.

    appreciate your thoughts on this ?
    many thanks,

  54. Hi Enigma!
    They should give you some warranty, no?
    I suspect 90% a relay is making that noise. You can look under the dash where the relays are. And then gently touch every relay and feel the small vibration to identify who make the clicking. And what you mean RPM it’ at 1? One thousand?

  55. Enigma

    Hi Vale,
    thanks, i ‘ll have a look under the dash for the faulty relay.
    yes, i meant 1000 rpm.

  56. Hello,i ‘m Adeniyi Oronsaye,from Kaduna Nigeria,West Africa. I bought VW Bora 1998 model last year(2008) June,it was a lovely car to drive but my car starts to smoke(black). I was told its the Air Flow Meter by my mechanic. i did tried changing the Air Flow Meter without any success.

    Please kind you advice on what to do,wheather is the Air Flow Meter that is the problem.


  57. Hello. I have a 2000 passat 1.8t automatic. The engine light/emissions workshop came one today. I cleaned out the airbox and air filter but havent bought a new filter yet. I reset the light and it came back on could this be the air filter?

  58. Hi Adeniyi and Matt!
    Adeniyi – wellcome and congratulations for your car. Unfortunately if the car have a lot of black smoke, not necessarily is the MAF sensor bad. Also can be the injectors or a bad turbo or a puncture in the turbo hose or the Air Filter is clogged.

    Matt – for the engine emission warning light, after the air filter, also you should check the MAF sensor, (try cleaning) but it’s better to do a Vagcom diagnostic scan to see what are the error codes.

  59. Juri

    Hi there,
    I got a Passat 1.9 TDi 1999 , everytime I start to drive ABS light and hanbrake light to appear on the dash.I red already many topics on faulty VW ABS units, so I suggesting that unit is wrong or can be something else such a ABS sensor???
    The light used to appear and disappear but now is staying on
    by the whole journey.
    Thanks for help

  60. Daniel

    Hey I have a 03 passat 1.8l with 13000 miles that shakes when it idles…. But at speed it’s fine it lags a littlebit when I first giveit gas… And when I coast off the gas at 1200 rpm the car jerks but I slip it into neutral and it stops… What’s the problem

  61. Hi Juri and Daniel 🙂
    Chek the sensor for the brake plates, i think is in front left, but also could be o both wheels. It is posible that your brake plates are old and thin or the sesor wires have bad electrical contact.

    Daniel – I presume your car it’s Diesel. So 75% one of the injectors are malfunctioning.

  62. Luis

    Dear Vale,
    I have a 2004 passat 1.8T, and about 1 month ago i rebuilt the engine. The turbo system and innercooler had oil. After i rebuilt the engine, it was working great. Then the Check Engine Light came on. The diagnostic said “Engine is too Lean.” I already replace to vacuum hoses. But i dont think it was a vacuum lick. The other option is the HO2 sensor or the MAF sensor. How would i know which one it is?

  63. Richard

    I have a 2001 Passat 2.8. I thought It was my MAF….I have no loss of power. The idle drops suddenly then picks back up. When stoping at a stop it can even shut off. There is also a clicking sound coming from the left side of the dash. Mosty happens when the car is cold. I am at a loss. Dealership to $.

  64. Hi Luis and Richard 🙂
    Luis- Usualy the MAF sensor don’t cause a check engine light, so i think is the O2 sensor.

    Richard – Please check if is the Relay 109 who make the clicking noise. This is the main power relay and is known to cause similar problems due to a faulty soldering, and was changed by VW with a new one. To know witch you have: the old one is black, the new one is gray.

  65. Richard

    Thanks for your help, I just ordered a new MAF sensor. I hope that helps that. I could not find a 109 relay. Is the 109 relay diesel only, mine is not diesel. This relay sounds seem to stop after in warms up a bit. But if it is cold the relay seems to click over and over again for about five minuntes or so.

  66. ben


    So i have 98 passet that wont turn over. The lights got left on in -25 degree Cel weather and the battary froze. I replaced the battary but the car still wont start. When i turn the key it turns over and i can her the car want to start and the rpm move but then it dies and all you can hear is the starter struggling. Ive plugged it in and also tried warming the engine with heaters but it still wont go.

  67. Joe Duran

    I just bought a 98 Passat 1.8. The problem that I have is when I accelerate. Once the RPMS reach about 1800-2000 RPMS the motor stops accelerating and goes back to idle. If I hold the gas down a bit it will go up to same RPMS 1800-2000 and drop then go back up to same RPMS 1800-2000 and drop. This will keep repeating if I hold gas down a little. On the other hand if I hold the gas down alot to around 5000 RPMs the engine will have to problem staying there.

    When I try to drive the car it will accelerate then drop back down then accelerate and keep repeating. I replaced the MAF and this is still happening. I noticed if I try pumping the gas to try and keep it idle around 2400 RPMs there is like a popping noise. Almost sounds like a blow off valve. There is no blow off valve install aftermarket though.
    Please Help

  68. pat

    Hey man

    Hey i bought a 99 vw passat with a 1.8t i changed the maf because the car was jerking/bucking well i tryed to clean the maf and broke it so just bought a reman the car worked fine for a day perfect no bucking nothing then i shut it off to go in walmart and when i come back out the car cranks and shuts off finally i get it to stay alive but when i go to take off all the car did was buck so i brought it to the shop and they said it was the maf so i got a other reman since it was under warranty put it in worked fine no bucking no nothing 45 mins later everything starting happening again bucking stalling so i took the maf off again and they shop had told me to smell they old maf and i smelled a burn smell from it so when i took it off again i got the same smell so this is my 3rd MAF and i have no money to get a other just had a daughter so i got no spare cash and need my car to run PLease help me

  69. turbolover01

    Hey there, I have a 2001.5 Passat (new body style) with an intermitent problem with my MAF sensor. I am having trouble finding it under the hood. Looking at your pictures, our bays are pretty much identical, except for the air box that holds the filter, and I’d assume everything after that as well. It is a 1.8T motor and even with the internet, a second pair of eyes and a repair book, I have yet to find it. Any suggestions would help a lot. I want to clean it and clear the code before spending $275 USD on a new one, to see if it fixes the problem. So far it has only sputtered, or lost power once, and has been fine ever since, but the engine light stays. Thanks for your time!!!

  70. Hi all! 🙂 Sorry for my late answers but I was in a trip in Bulgaria, Rila Mountains, Musala Peak. This winter is hard in Bulgaria so my VW Passat was well tested an me also 🙂

    Hi Ben! Have you check if is not ice in your fuel pipes? At so low temepratures it could be.

    Hi Joe! Well it could be the actuator or some pipes or even a the BOW valve but the stock one.
    The poping noise is when you push or when you remove the foot from the gas. If you find the problem, I will be happy to hear what it was.

    Hi Pat! – The MAF Sensor only don’t usually make the car jerking. It could be another problem. Also, the service shop should tell you why the MAF is burn. This is the main problem, but I doubt the MAF is the problem. And what about the service warranty? Check the wires for a short.

    Hi turbolover! – well, from 12000km is hard for me to help but for sure, if you take inch by inch your air intake from the
    air filter to the turbo, you will find it. Try with a small mirror to look under and in the pipe, and don’t forget to look in the airfilter box too. Chech for some wires. By the way, it’s outrageous expensive a MAF sensor at you. At us, it’s only about 90 – 120 USD

    Merry Christmas at all! 🙂

  71. robert

    i need help, i own a 2000 volkswagon passat 1.9tdi and there is a serious loss of power, the turbo seems to be working ok, no smoke flying out of the car,, i also tried unplugging the MAF and stil not difference, i need help to sort this cause its getting me down

  72. PAt

    i bought my car used with 128k miles and it ran fine i read on a thread something about when you un hook the battery on these passat it was the tps go crazy and now thinking about it i had unhooked the battery have you ever heard anything like this before ?

  73. Hi Robert and Pat!

    Robert, if you unplug the MAF sensor, and is no worse, 75% is that the MAF is the problem, because, normally without MAF the car must run much worse. But also if you already are in limp mode, is no diference.

    Pat – no, it should be no problem.

  74. pat

    OKay so when i unhook the MAF it runs worse the car wont stay running, and now i have a high idle and a bucking when i drive if i unhook the hose that goes to the throttle body and just barely set it up to the throttle body the idle goes back down to 800 but when i put the hose on and clamp it down my idle sits at 1500 any idea ?

  75. ben

    Hey Vale,

    It turned out that the spark plugs needed replacing.

    Now that the car died i have to get the number off the back of the radio so i can get the safe mode number from the dealer. I found this site that shows me how to remove the radio but the car is a newer model. Will this process still work for my 98 passat.

  76. Hi Ben!
    I understand your car is another model.
    Maybe this pictures below will help you to take out the radio:
    If is the same model like yours I can help you better. Take a look:

  77. ben

    Ya thats the one. Just having a little trouble reading it!!!!

  78. Hi Ben, sorry I will translate this page. :O
    Anyway, look carefully at the first two pictures. (click to enlarge)
    You should put and press inside of the two lateral small vertical holes , slots, of the autoradio, two blades or something like that (in picture I use bended steel blades from paper file folders)
    So, with two small blades you should push simultaneously to remove the locks who keep the radio in place and then pull the radio out. That is! There are no screws or else.
    Good luck!
    By the way , my radio code was write on a paper in the car manual.

  79. DURAK

    hellow i wont lern MAF sensor repair lerning i seking germany and turkeh tahnk

  80. Hiya!

    I am fairly new to this community + just thought it would be a good idea to introduce myself and say „Hi”.


    Plr Gold Member Review

  81. David Chapman

    This instruction does not apply to the Passat 2001.5 B5
    1.8T engine.
    I tried to follow the above instructions but no luck.
    First there are NO screws to remove the air box only clips in god awful places. The sensor is held into air box with
    unique torx screws which require special tools.
    The hose clamps are the crimped variety which require destruction and replacement with screw type.
    What ever vw charges to clean this thing is worth it.
    This is the best example of the worst form of engineering.
    VW engineers should be embarrassed. Even the air filter is not accessible. If anyone decides to do this maintenance them selves they will need more tools and more patience and more beer that set out above.

  82. Just thought I should post a note introducing myself. I write for the new United States Congress site.

    I am very interested in peoples opinion on the website.

  83. kevin

    hello, iv got a vw passat v6 tdi 2001, and i think the air flo sensor as gone, the is not muth power wen i disconect the plug off the sensor, its still the same, so i gess its gone, does anyone no were i can get a air flo sensor from because the am expensive on ebay, regards

  84. ibraimo pestamgy

    hello , can you help me, giving me the wiring sequence off the MAF of the passat tdi 2001?
    i take out the wirings from the switch and now i dont know the write sequebce off the wirings
    tanks you

  85. ibraimo pestamgy

    hello , can you help me, giving me the MAF wiring sequence of the passat 1.9 tdi 2001?
    i take out the wirings from the MAF switch and now i dont know the write sequebce off the wirings.
    tanks you

  86. Sam

    Hi Vale,

    I have a 2002 passat 1.8Turbo automatic. It accelerates very sluggish. When I push on the gas pedal, the engine RPM can easily go 3000rpm or more but the car doesn’t really accelerate quickly. The engine sounds quite aloud during acceleration.
    Does it mean the engine is losing power or need more fuel? Or means there is an air leaking somewhere? Or it can be due to the MAF? Thank you if you have any suggestions!


  87. Hi Sam!
    If you are really sure that the engine RPM go up quick, but the speed no, i think the problem is not the engine, but the problem could be at the transmission in the gear box.

  88. kevin

    can any one help me, iv got a vw passat v6 tdi, 2001, all of a sudden its lost ists power, its 150bhp it drives like 90bhp, someone told me is the maf air flow sensor, so i bourght one of those, and its still the same, as anyone got any sergestions, thanks

  89. bob thorpe

    Hi there 🙂
    the problem is 1998 1.8t passat auto .
    starts all ok , but wont rev past 1200 rpm, have disconected maff and will not start so assume ok , car was fine untill i replaced alternator and battery, shows no fault codes ?
    any one help ?
    regards bob .

  90. Sylvia De La Cruz

    Hi My name is Sylvia single mom so need to try to save money fixing 2002 Passat 1.8 turbo. turn off engine and check oil light was coming on. Went to have oil change the car still displays to turn off took to check engine light. They check the code and it showed Air low Meter / Mass Air Sensor they told me that would cause it to display that message is that true??? dont want to blow a motor trying to find someone to check the oil pressure but it is late saturday will wait for monday. want to make sure oil pump is not going out. what can it be?? a sensor.

  91. Hi Sylvia!
    I don’t understand, is the chek engine on or the check oil on?
    And for oil, is the yellow or red light.
    Anyway, the MAF sensor don’t put on oil light.
    If the check oil red light on, is dangerous to go with the car.
    Hope to help.

  92. +258824603760

    Hi there!
    I have a big problem, i change the wiring sequence of the MAF on my passat 1.9Tdi and now the car loss power because the wiring sequence is wrong.
    can anyone send to me a picture with the wiring sequence in the MAF our any other solution?
    Tank you for all.

  93. The Vale

    Hi there!
    I will try send you a picture with MAF wiring, in next few days. But you know that you have very good chances that you have burn your MAF electronics or even worse, something at ECU.

  94. Anonim

    Hi there Vale.
    Tank you for the help.
    if you can, make sure that is a passat 1.9tdi 2001 model wiring sequence of the MAF.
    You can send the pictures for may mail: or

  95. ibraimo pestamgy

    Hi there Vale

  96. Rob

    Hi Vale,

    I think I may have a similar issue to what Sylvia was talking about. My car accelerates more slowly and sometimes at idle the RPMs bounce and occasionally the car dies unless I accelerate when it shutters like that.

    But the weirdest thing it does is after returning to in town driving from highway driving (decelerating from 80-~45 mph) The oil pressure light blinks and beeps at me every couple minutes. I’ve had my oil pressure checked and it was running with strong pressure (around 55-65 lbs).

    Any ideas what could cause this? Thanks

  97. Rob

    99′ passat 1.8t btw

  98. cm84


    nu am passat, ci un leon 2.0 tdi, dar principiul e cam la fel. de ceva vreme, tot primesc urmatoarele erori la scanare:
    16485 – Mass Air Flow Sensor (G70): Implausible Signal
    18000 – Altitude Sensor / Boost Pressure Sensor: Implausible Correlation
    si mai nou,
    18051 – Please check DTC Memory of Electric Load Controller

    le sterg, reapar, la momente random.
    simptome: masina poate merge perfect, sau in limp mode, la random. dar atunci cand trage, trage cum ar trebui sa o faca. in schimb, in limp nu intra deloc turbina si bineinteles ca nu am putere…
    ideea e ca daca sterg aceste erori, sigur va merge bine. asta pana cand reapar. e stresant ca nu pot determina exact in ce moment se declanseaza problema.

    am facut deja o sesiune de scos/pus la loc mufe debitmetru si cele din jur. dar nu a fost o rezolvare.

    cum as putea verifica firele senzorului cu multimetrul ?
    si daca stii, unde sunt punctele de masa, care se pare ca trebuie verificate de coroziune, dupa sfaturile ross tech ?

    mersi mult

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