Error P0102 Maf Sensor - How to test MAF to see if it is working?

ARMY

Well-known member
Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
Hey guys,
I have a P0102 error, MAF sensor, low air input /circuit something or other.
Air filter is not bad, I figure, maybe some contaminent on the MAF, which I will be cleaning later on, but I am curious, if I wanna run a test on the MAF to see if it is working right, how do I do it? My mech friend asked me to find out if there are certain specs on testing like at 70 degrees some much wattage or resistance etc etc... Im not mechanically inclined so it was semi latin to me. But he would like ot test the MAF to rule it in or out. Other thoguh might be a seal going at intercooler/turbo allowing a little oil to enter the air, not sure either. Lite dusting in tube, but not sure if that was a 1 time thing or ongoing.
please help!:confused:

I had my accuator replaced, about 3 months prior to the new issue. the symptoms are much the same. low power, like the turbo isnt running. I disconnected the MAF, minor improvment, atleat its consistant, before on occassion it would get a little boggy for a few sec. I dont know if Im in Limp Mode or what, but the P0102 error leads me to believe MAF or EGR is sticky.
Any help? Something I can give to my diesel mech friend to look into ??
Thanks!
Gary
 
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Canadian_Grizzly

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Apr 7, 2005
Location
British Columbia, Canada
TDI
02 Jetta TDI
Gary simple test for the MAF is unplug it again. If it runs better then replace the MAF.
You can tell if you are getting an overboost or going into Limp mode because the power will return instantly when you cycle the ignition.
 

ARMY

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Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
I have unplugged and replugged a few times not any huge difference.
We wiped the code and it came back.
 

BeeselDietle

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Location
Pensacola, Fl.
TDI
01 beetle
Your intake may also be clogged, when mine was clogged unplugging the maf made no difference even though it was bad. Once I cleaned the intake, unplugging the maf made a huge difference
 

rdkern

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Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Three tests for the MAF.

First one you've done (unplug etc).
Second, with a warm engine, sitting in your driveway, put the fuel request pedal ("gas pedal") to the floor and see if the engine gets to 5100 rpms. It should get quite close, but if it stops at 4800 or less, the MAF is most likely bad.

Third, get a VagCom, and do a MAF run while logging MAF requested and MAF actual. Find a safe stretch of straight road, and run it from 2-4000 rpms with the pedal to the floor, shift, do it again in third, and if you have space and a reasonably legal environment, do it in fourth. In each of these runs, requested should be at 850, and you should see spikes of about 1000 in the actual. If actual <850, bad MAF. This is the best test, but other things could cause issues such as clogged intake or something wrong with the boost system throwing you into "limp" mode.

Good luck!
 

Curious Chris

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Jun 11, 2001
Location
Pineview GA
TDI
Jetta Wagon 2003 RIP Rockford IL
When you do the pedal to the floor test also log throttle position, MAP specified and MAP actual. The pedal to the floor aka 100% throttle eliminates adaptation. Adding MAP to the log gives you turbocharger performance: low airflow reported by MAF with no turbocharger pressure issues points to air intake issue such as clogged intake or airfilter.

After you log it having the throttle position allows you to filter out all partial throttle data and only look at the 100% data. Oh repeat the 2000-4200 rpm test 3 or 4 times. I like third gear or higher as you need the system to sense a load to get good results.
 

ARMY

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Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
Curious Chris said:
When you do the pedal to the floor test also log throttle position, MAP specified and MAP actual. The pedal to the floor aka 100% throttle eliminates adaptation. Adding MAP to the log gives you turbocharger performance: low airflow reported by MAF with no turbocharger pressure issues points to air intake issue such as clogged intake or airfilter.

After you log it having the throttle position allows you to filter out all partial throttle data and only look at the 100% data. Oh repeat the 2000-4200 rpm test 3 or 4 times. I like third gear or higher as you need the system to sense a load to get good results.
Okay, will this proceedure vary at all with an Automatic?
I have a 2002 jetta tdi Automatic with 310,000 on the odom.
Thanks!
gary
 

rdkern

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May 21, 2004
Location
Humboldt Co CA
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Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
You may have to manually shift if the trannie doesn't want you to go to 4K, but should be tested the same way. Remember, don't just get to 4K, but get there with the foot planted on the floorboard squishing the pedal.
 

ymz

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May 12, 2003
Location
Between Toronto & Montreal
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2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
Well, on my car the "unplug MAFs" routine produced no change whatsoever - the car still ran extremely poorly... the "floor the accelerator pedal" test also didn't show anything... car went to over 5100 rpm... watching the Vag-Com data of course showed no change in "actual" whatsoever - no matter the speed or the accelerator position...

Changed the MAFs, and everything's back to normal... The original MAFs sure died in a hurry!!! Car was working just fine and... suddenly, no power (and a CEL)...

Yuri.
 
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ARMY

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Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
Well, unplugged was slightly better, and more consistant power.
I ran in 1st easily to 5200 (on automatic first gear)
Wingnut recomends a MAF change, and he's very solid on this, and seems thats what this thread is suggesting to, with those outcomes, so, Ill look into that, and let yas know!
Gary
 

ARMY

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Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
Yuri,
Are you saying after y ou changed the MAF< the new one died fast too?
Gary

ymz said:
Well, on my car the "unplug MAFs" routine produced no change whatsoever - the car still ran extremely poorly... the "floor the accelerator pedal" test also didn't show anything... car went to over 5100 rpm... watching the Vag-Com data of course showed no change in "actual" whatsoever - no matter the speed or the accelerator position...

Changed the MAFs, and everything's back to normal... It sure died in a hurry!!! Car was working just fine and... suddenly, no power (and a CEL)...

Yuri.
 

ymz

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Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
No... I was saying that the original MAFs died very suddenly - overnight, seemingly... I'll edit the original message to avoid confusion...

Yuri.
 

rdkern

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Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Oil in the air tube prior to the MAF ...... where did that come from? If stock, I don't know of anywhere it could come from. Are you a K&N believer?
 

ARMY

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Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
rdkern said:
Oil in the air tube prior to the MAF ...... where did that come from? If stock, I don't know of anywhere it could come from. Are you a K&N believer?
yeah, just was informed, its Oily crank case vapours and normal. So, I'll be replacing the MAF as people all seem to agree on this. Thanks for all the help too guys!!

I might pick up an K&N down the road, as for now, premium stock versions.
Gary
 

ARMY

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Joined
Nov 26, 2005
Location
Windsor, Ont Canada
TDI
Current is 2009 TDI 140K - Former VWs 2003 Bora TDI + 2004 Touareg V6
ymz said:
Many (most ??) here would tell you not to bother...

All the best,

Yuri.
Really? the stock type is sufficient?
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
My comment concerning K&N is that it is one of the ways oil can get to the MAF. Stock paper filter is more than sufficient.
 

jettatdiwagon04

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Mar 11, 2016
Location
Mathias, WV
TDI
jetta wagon, passat, jetta sedan
I am new to this forum.

My jetta is lazy going up hills, check engine came on. Husband suspected fuel filter. He replaced it. I had garage reset check engine - I was told MAF sensor code was culprit.

Vehicle bucking intermittently now. Not driving it much. It does seem to improve shortly after bucking. Tried RPM max in neutral, it can do it, but then when I drive, bucking occurs like it took all it had to do it. Cars knocks for 50 to 100 feet then improves gradually to full power. Have not gone back off flat road to test on hills, don't want to damage. When husband gets home we are going to try cleaning MAF, intake manifold and
 

ymz

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Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
If it's the MAFs, try disconnecting it to see if the car drives better, worse, or the same.

However... how many miles on the engine? the PD engine in your car (I assume you're talking about the 2004) is known for wearing out camshaft and lifters, and you may have more serious problems... If your mechanic isn't a TDI specialist (I don't know of anyone in your area), they may not diagnose it properly and it will cost you a small fortune for them to try and figure things out on the fly.

Good luck,

Yuri
 
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