P0101 code

wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
Keep getting a P0101 MAF MIL on a 2005 PD Jetta wagon with 115k miles.

I began by cleaning the MAF and clearing the code. It returned several days later.

Next I replaced the MAF and cleared the code. Again returning several days later.

It was then that I noticed the 3-4 inch diameter hose from the intercooler to the turbo was no longer seated correctly. The alum fitting on the turbo end was not inserted all the way into the corresponding fitting. The spring clip's bottom section was missing. I replaced the spring, cleared the code, but again the MIL returned.

Now I noticed that the alum fitting on the end of the hose no longer had it's little tabs that hold it behind the spring clip I already replaced. I replaced the hose, it clipped in just fine now, but as you suspected, the MIL came back again.

I'm at a bit of a loss.. No blockages on the intake side, air cleaner or snow screen. The intake has never been cleaned but we run the car agressively regularly and run DieselService full time.

Ideas??

thanks!
 

wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
Ok, I've searched and searched the forum, but really found nothing about a P0101 that doesn't go along with poor performance. Our '05 seems to continue to run just fine other than a very slight hesitation my wife reports. So slight I can't even detect it, but I don't drive the car full time.

I've seen some talk about a clogged intake. I've seen the cleaning done at a GTG and it didn't look fun so I'd sure like to really know that's the issue before pulling it apart.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
from the Ross Tech WIKI-


16485/P0101/000257 - Mass Air Flow Sensor (G70): Implausible Signal

Possible Symptoms
Loss of Power
Erratic Idle
Possible Causes
Mass Air Flow Sensor (G70) faulty
Air Leak(s) after Mass Air Flow Sensor (G70)
Intake Air Filter dirty/faulty
Ground Spots corroded or Paint Residue
Wiring and/or Connections from/to Mass Air Flow Sensor (G70) faulty
Possible Solutions
Check Intake Air Filter
Check Mass Air Flow Sensor (G70)
Check Ground Spots
Check Wiring and/or Connections from/to Mass Air Flow Sensor (G70)
Special Notes
In MY 1995-2002 (?) in Europe at VW-diesel-cars G70 had the bad reputation of slowly losing his performance, causing loss of power. It's not a matter of defective or breaking down, but it is filthy / dirty (not easy to clean). You can check functionality by making a log in [01-engine], [meas.blocks-08], group 003 (3e gear, full throttle, from 1700-4000rpm)
 
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wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
Yup, done everything on the list, still no joy,,, P0101 keeps coming back... Maybe I need a guru...argh...
 

Dimitri16V

Top Post Dawg
Joined
Jan 30, 2005
Location
DE
TDI
01 Golf, 04 Golf
just solved same issue on my PD. the wire from pin 4 in the MAF connector had an intermittent connection to ECU connector.
At the least , reseat the ECU connector . at most ohm out for continuity between both ends of wire
 

wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
just solved same issue on my PD. the wire from pin 4 in the MAF connector had an intermittent connection to ECU connector.
At the least , reseat the ECU connector . at most ohm out for continuity between both ends of wire

thanks, I'll check that... Do you recall the ECM pin? I 'spose I can RTFM, can't I? :rolleyes: The ECM has been touched in this car when it was RC'd, but it was years ago... hmmmm... Could it be that easy? Here's hoping! thanks!
 

Dimitri16V

Top Post Dawg
Joined
Jan 30, 2005
Location
DE
TDI
01 Golf, 04 Golf
pin 40 on big T94 pin connector. it should have a red/green wire on it. make sure you count the pins in the right direction to locate pin 40. it is supposed to have continuity with a pin in the MAf, i think it's 4, but check for the same wire color.

It could also be a loose T94 connector or pin 40 may be damaged. make sure the T94 engages and locks in place
 
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wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
pin 40 on big T94 pin connector. it should have a red/green wire on it. make sure you count the pins in the right direction to locate pin 40. it is supposed to have continuity with a pin in the MAf, i think it's 4, but check for the same wire color.

It could also be a loose T94 connector or pin 40 may be damaged. make sure the T94 engages and locks in place
Thanks! I pulled both connectors last night, cleaned them a bit and used some dielectric grease. (hopefully it likes that). I could not find the pinout in the FM so I closed it back up and reset the MIL. I'll check continuity next if it comes back.. thanks for the pin numbers...

The connector seemed to go back just fine and the lock seemed to work..

Rick
 

wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
I stumbled onto the PO0101 thread about stuffing the MAF connector with dielectric grease. I tried that last night... We'll see what the wife reports.
 

wetskier2000

Veteran Member
Joined
Aug 3, 2006
Location
NH
TDI
Gone: 05 Jetta GLS Wagon Current: 2015 GSW SEL 6MT
Intercooler??

Still no joy, ohmed out the connections just fine. Wiggling the wires didn't seem to matter. When following the bouncing ball that is the air input I notied that the right inner fender had a pretty big "pizza" slice out of the front section. Looks like it came loose and rubbed the tire. I wonder if something got thrown into the intercooler or its plumbing. I'll have to get it on the lift and take a closer look...

Anyone think this might be a PO0101?

thanks!
 

Diesel Maniak

Well-known member
Joined
May 10, 2010
Location
Canada
TDI
74 Bug
same code here p0101

i have no loss in power or fuel economy

any updates on this situation ? same issue here , though i switched maf from my other bew to my wagon bew and the light came on after 2 hours of driving

only thing i see happening is the intercooler pipe on the egr side where the c clip is , the hose is coming off and i hear air escaping

so i ordered a kerma bew hose fix kit

i am gonna drive my jetta with the wagons maf tommorow morning and see if my jetta throws a code
 
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jetta 97

Vendor
Joined
Dec 25, 2008
Location
Dallas (McKinney) ,TX ,USA
TDI
2 X Jatta MK5 2006
Believe or not but recently I found that camshaft wear can do this.
I had BRM that customer was having same problem even with new MAF and new camshaft fixed problem.
I one more guy told me on his Beetle 2004 BEW it was a same thing.After cam replacement problem was gone.
 

Diesel Maniak

Well-known member
Joined
May 10, 2010
Location
Canada
TDI
74 Bug
Believe or not but recently I found that camshaft wear can do this.
I had BRM that customer was having same problem even with new MAF and new camshaft fixed problem.
I one more guy told me on his Beetle 2004 BEW it was a same thing.After cam replacement problem was gone.


thats an expensive fix :mad:

so far got a new clip and hose fix kit - the engine light dont come on anymore
 

evolDiesel

Veteran Member
Joined
Feb 15, 2011
Location
PACIFIC NW
TDI
2011 JSW 6MT (and several others in the past)
thats an expensive fix :mad:

so far got a new clip and hose fix kit - the engine light dont come on anymore
Diesel maniak - did that kerma hose kit end up being the final solution?

Wetskier2000 - did you ever find the solution?

I have same situation, no power loss, recently installed a BoostLogic intake.

Jack
 

perrya

Veteran Member
Joined
Dec 16, 2011
Location
california
TDI
2006 Jetta BRM with 200K
When you guys refer to clogged intake, are you talking about intake manifold? air intake? be specific.
 

rydogg

Veteran Member
Joined
Jan 29, 2008
Location
Indiana
TDI
Passat
Still no joy, ohmed out the connections just fine. Wiggling the wires didn't seem to matter. When following the bouncing ball that is the air input I notied that the right inner fender had a pretty big "pizza" slice out of the front section. Looks like it came loose and rubbed the tire. I wonder if something got thrown into the intercooler or its plumbing. I'll have to get it on the lift and take a closer look...

Anyone think this might be a PO0101?

thanks!
Wetskier, did you ever get this figured out? :confused:
 

JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
Got the P0101 today, but did not experience any driveability problems. Cleared it with my SG and two hours later coming home there was no CEL. I'll check all intake air hoses first. The funny thing is I guessed right about the actual code.
 
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donDavide

Veteran Member
Joined
Oct 4, 2005
Location
Severna Park, Maryland USA
TDI
2003 Jetta ;2006 Golf; 2015 Jetta S
I am getting the issue. I just replaced my MAF and the code came back. Seems to happen when the temperature is over 90 and humid and running AC and have gone up a hill.
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
I am getting the issue. I just replaced my MAF and the code came back. Seems to happen when the temperature is over 90 and humid and running AC and have gone up a hill.
Which year car do you have?
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Changing the component named in the code description is a rookie mistake, common, you're forgiven.
Other than reading the thread above, see this post . Should have you covered. And if you're using an oiled air filter (K&N), get rid of it.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
If it is one of the three 4 cyl PDs sold here, a P0101 is usually indicative of a small charge air leak, but has not progressed to the point that the ECU cannot maintain boost and flag a P0299 low boost DTC (and place the engine in limp mode).

So check the charge air system, specifically the o-rings at the snap-fit connectors. Depending on which engine it is, I can give more specific hints.
 

donDavide

Veteran Member
Joined
Oct 4, 2005
Location
Severna Park, Maryland USA
TDI
2003 Jetta ;2006 Golf; 2015 Jetta S
from the Ross Tech WIKI-


16485/P0101/000257 - Mass Air Flow Sensor (G70): Implausible Signal

Possible Symptoms
Loss of Power
Erratic Idle
Possible Causes
Mass Air Flow Sensor (G70) faulty
Air Leak(s) after Mass Air Flow Sensor (G70)
Intake Air Filter dirty/faulty
Ground Spots corroded or Paint Residue
Wiring and/or Connections from/to Mass Air Flow Sensor (G70) faulty
Possible Solutions
Check Intake Air Filter
Check Mass Air Flow Sensor (G70)
Check Ground Spots
Check Wiring and/or Connections from/to Mass Air Flow Sensor (G70)
Special Notes
In MY 1995-2002 (?) in Europe at VW-diesel-cars G70 had the bad reputation of slowly losing his performance, causing loss of power. It's not a matter of defective or breaking down, but it is filthy / dirty (not easy to clean). You can check functionality by making a log in [01-engine], [meas.blocks-08], group 003 (3e gear, full throttle, from 1700-4000rpm)
I have seen this. Rookie mistake? LOL. It has a Mann air filter and it was changed at 140K(has 144k now). Car runs fine. It first happened last summer in July going up a hill (and again in the exact same place in Sykesville, MD) Did come on again until the weather got hot again this summer. and it comes on often now. It has been hot and humid (imagine that in summer)
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
2006 Mk4 Golf BEW
Check your camshaft. P0101 is often the first code to show up when the cam is getting worn. It could also be a boost leak.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
In addition to what Oilhammer posted, check the wires/connector to the MAF.
I had not heard about the cam being involved, but I can believe it. You have one of the 2 or 3 model years that sometimes suffer from pre-mature cam wear. Easy enough to pop the valve cover and inspect.
 

Alchemist

Veteran Member
Joined
Nov 3, 2007
Location
Lethbridge, Alberta
TDI
'04 ALH Golf
I was getting the P0101 code at every down shift. After some searching and trials, it turned out to be a leaking EGR valve.

Also, check the bottom front of the intercooler. The plastic air duct is a bit too close and rubs holes in the aluminum tubes. A little trim fixes it.
 
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