# P0103 MAF



## 01Golf (Sep 30, 2008)

A few weeks ago i got a code on my 01 Golf. It was P0102 (MAF circuit low input). After resetting the code a few times & having it come back, I got a new one from the dealer (very expensive), reset the code & the car was fine for about 50 miles then the check engine light came back. This time it gave me a different MAF code P0103 (MAF circuit high input). Could the dealer have given me a bad MAF sensor? I have reset the latest code a few times now but it comes back with the P0103. Any ideas? After reading so much here about MAF I know the part # on the one the dealer gave me was the latest & greatest
P# 06A906461A


_Modified by 01Golf at 1:16 PM 4-11-2009_


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## jcee2k5 (Feb 10, 2009)

I have that same code P0102, I just reset the code & will wait to see if it comes back. If so, I think a new MAF is going to have to be ordered, but from GAP. Stealerships want more $$ for this piece.


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## 01Golf (Sep 30, 2008)

I know you dont want to hear this but get an OEM Bosch MAF from the dealer. I bought a cheaper MAF from an autoparts store & it was bad. I returned it & got another, that was bad (throwing codes & wouldnt run right). I brought that one back, told the cheap auto parts store that i just wanted a refund ($120.00) & went to the dealer, pair $222.85 (last week) & the car now runs fine but i have the new code P0103. People here told me to get an OEM MAF & not a cheap auto parts store MAF. I didnt listen LOL. I found out the hard way so i am passing this on to you. Get the OEM one from the dealer. This is the one sensor you cant cheap out on.


_Modified by 01Golf at 10:09 AM 4-12-2009_


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## 01Golf (Sep 30, 2008)

I know you dont want to hear this but get an OEM Bosch MAF from the dealer. I bought a cheaper on from an autoparts store & it was bad. I returned it & got another, that was bad (throwing codes & wouldnt run right). I brought that one back, told the cheap auto parts store that i just wanted a refund (120.00) & went to the dealer, pair 222.85 (last week) & the car now runs fine but i have the new code P0103. People here told me to get an OEM one & not a cheap auto parts store one. I didnt listen LOL. I found out the hard way so i am passing this on to you. Get the OEM one from the dealer. This is the one sensor you cant cheap out on.


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## jcee2k5 (Feb 10, 2009)

Yea, the MAF from German Auto Parts (GAP) is an OEM Bosch for $194. It's a couple bucks cheaper than the stealership. 
I reset the codes last night & will wait to see if that code comes back. Did your CEL come on? Mine didn't come on & decided to scan it anyways & the code came up P0102. Mine is (MAF circuit low input) something like that. Did you try cleaning the MAF? I cleaned mine about 2 weeks ago already, maybe I should try again.
http://www.germanautoparts.com...l/5/2


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## 01Golf (Sep 30, 2008)

Yeah my code P0103 came back last night & I have a new OEM Bosch MAF from the dealer I put in a few days ago! HMMM its got me stumped. I talked to a VW rep & he said they wont repl the new MAF unless I take the car in for a checkover/diagnostic at $92.00 & if they find the new MAF i put in from them is bad, they will repl the MAF and waive the check over fee. They also said that if it wasnt the MAF thats the prob (how could it not be with a MAF code??) they will tell me what is the prob so i can fix it. The guy was also telling about how the connector to the MAF can go bad.


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## FL 2.0L (Aug 1, 2002)

Maybe try cleaning the connector yourself and try some dielectric grease in there. Any air leaks before the maf?


_Modified by FL 2.0L at 11:35 AM 4-12-2009_


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## 01Golf (Sep 30, 2008)

There are no air leaks before the MAF. Everything looks & sounds tip top.


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## rjhinman (Apr 25, 2010)

*Anybody ever find a solution to this problem?*

I've got the same issue on an '01 Cabrio... replaced the MAF, and rewired a new harness onto the existing wires. At first I was getting a low input P102. Now I'm getting a high input code P103. 
I'm also getting high resistance on one, (but not both), of the internal grounds at the MAF harness. 
Checked resistance between the ECU wiring harness and the MAF harness, and all check out fine. Where could this resistance be coming from that is affecting only one of my MAF internal grounds?
Looking for an ECU pinout diagram so I can look into it further. Any help is appreciated.


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## dkfackler (Feb 8, 2010)

*Re: (01Golf)*

What's your engine code? I have an '01 with the AZG engine and the same issue. I am beginning to suspect the ECM. In running the procedure in Bentley, there is no continuity from terminal 1 of the harness to ground(it grounds through the ECM). I've removed the harness from the ECM and tested all the wiring(good). All that remains is a dodgy ECM. Sigh. As a last-ditch effort, I'll open the plenum and shine up the ground terminals.
IIRC, there are some Golf models with the AZG engine.
As I digest the wiring diagrams, there are several circuits grounding via this same current track-- one is the upstream O2 sensor, so that is probably complicit in the rich running condition.
A MAF code doesn't always mean a bad MAF. It can be wiring, throttle adaptation or a host of other things.


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## ikerpup (Mar 27, 2010)

*Re: Anybody ever find a solution to this problem? (rjhinman)*


_Quote, originally posted by *rjhinman* »_I've got the same issue on an '01 Cabrio... 
. . .
Looking for an ECU pinout diagram so I can look into it further. Any help is appreciated.

If you find the pinout please let me know as I'm interesting in locating it as well. Although when I have time I'm planning on tracing out the wiring diagrams, so if I get that done I'll prolly post it.


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## rjhinman (Apr 25, 2010)

*P0102 & P0103*

So I misrepresented a bit on my issue as I was looking at a DIY that didn't apply to my situation.
My MAF has a bad ground wire. Continuity checks out fine to the ECU wiring harness, but I'm not sure where to go from there. I was reading a High MAF Input: Code P0103.
I installed a second ground wire, (not to the ECU, but directly to the body), my return signal readings came down to normal immediately Now I'm reading a Low MAF Input: Code P0102.
Any ideas?


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## dkfackler (Feb 8, 2010)

*Re: P0102 & P0103 (rjhinman)*

I had been considering this very action. My AZG has the same condition-- I'm considering an ECM replacement, but would like more input confirming the cause before dropping the cash.

To determine the P0102 cause, try this:
Take your ride out on the highway and, with the scanner connected and reading the airflow in grams/sec, run up to redline in 2nd gear. Take someone with you as a scanner operator/reader
IIRC, the AZG is 115hp, and nominal spec for a MAF is ~hp x .8, so you should see ~92g/sec (115 x .8)airflow at redline. If you see significantly less. I'd suspect the MAF. 
See this thread on fuel trim:
http://forums.vwvortex.com/zerothread?id=1201806
Let us know what you learn.


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## dkfackler (Feb 8, 2010)

rjhinman said:


> I'm also getting high resistance on one, (but not both), of the internal grounds at the MAF harness.
> Checked resistance between the ECU wiring harness and the MAF harness, and all check out fine. Where could this resistance be coming from that is affecting only one of my MAF internal grounds?
> Looking for an ECU pinout diagram so I can look into it further. Any help is appreciated.


 What do you mean by 'high resistance'; >1.5 ohm, but less than infinity, or infinity? Infinity is open, or non-conducting and if your car is like my AZG, that wire grounds through the ECM and probably means the ECM has failed. If you have less than infinity, you likely have a bad connection. In my experience, it's easier to replace a wire than to divine the location of a bad connection. The factory wires are tiny, which makes them somewhat fragile.


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## dkfackler (Feb 8, 2010)

rjhinman said:


> I installed a second ground wire, (not to the ECU, but directly to the body), my return signal readings came down to normal immediately Now I'm reading a Low MAF Input: Code P0102.
> Any ideas?


 I tried this (backprobing terminal 1 in the connector to ground) and still got the P0172 that I had previously, and also got P0112-- intake air temp high-- a reading of 140 C! If I removed my new ground, the reading came back to ambient temperature. 

The mysteries continue.


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## rjhinman (Apr 25, 2010)

So after cleaning the grounds underneath the battery, (which showed some, but not excessive corrosion), I reconnected the battery with the ignition switch turned on...now my throttle-body is throwing codes, (0121 and 1544), and I think I'm in need of an adaptation, hoping I didn't fry the TCM. Now when I run the car I can sometimes get the revs up, but most of the time when I hit the gas, it bogs down and dies. 

Needless to say, I won't be taking the car out on the highway to do the recommeded test until I can get the thing running reliably. Also, I only have a code puller, can't measure airflow. I just replaced the MAF and the wiring harness, so I'm hoping that the MAF is good. 

I'm getting high resistance, (~5 ohms), on the groundwire at the MAF harness. Again, it checks out fine through both resistance and voltage drop tests from the MAF harness to the ECU, so the problem is not located in the wiring between the MAF harness and the ECU. Correct me if I'm wrong, but regardless of the condition of the MAF, I need a good ground, so I think solving the bad ground is the first thing to tackle? then I'll move to whether my new MAF is bad? 

I mentioned in a previous post that I ran a ground directly from the MAF harness to the body, and that brought my MAF signal readings down to around 1.5V at idle, but then I was throwing a P0102, (LOW MAF input signal). Perhaps there's a reason the MAF is grounded internally back to the ECU, providing some necessary information to the ECU to determine whether the MAF signal is either too high or too low? Any ideas on that? 

So without an ECU pinout, and knowing that the under-battery grounds had some corrosion, I think I'm left with tracing backwards from those ground-wires to see if any of them are bad. I'll also trace back the grounds on the front of the engine block to see if either of them are the culprit. I hate to pull wiring bundles apart and check out things that may well be completely unrelated to my problem, but at this point I'm not sure where else to start. 

Any other ideas out there, i'm all ears.


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## rjhinman (Apr 25, 2010)

dkfackler said:


> A MAF code doesn't always mean a bad MAF. It can be wiring, throttle adaptation or a host of other things.


 I've read that throttle adaptation should not be performed unless all other codes are clear, but you seem to indicate that a throttle adaptation could actually clear the MAF code? I don't think a throttle adaptation will solve my bad ground , but once I get the ground figured out, if I'm still throwing codes, I'd be interested to see whether an adaptation takes care of the MAF code. 

Thoughts?


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## 01Golf (Sep 30, 2008)

Bringing this back from the dead. It turns out when my original MAF sensor died and I replaced it w/ am OEM one right from the dealer.....they gave me the wrong MAF sensor! Idiots! So I got the right one shortly after and its been running great now for the past 2 years! Just wanted to share!


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## mk3blackvw (Feb 12, 2009)

I just installed new MAF sensor that I got on eBay brand new for $51.00 free shipping. Beat that


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## playsomehoops (Jul 14, 2004)

I'm curious to if mk3blackvw's MAF is still working. I bought one around the same time for the same price on Ebay. It worked fine, but now I started to get the P0103 code, which is a different code than I had before. I'm trying to figure out if I need to get another one and pay more for it.

Had P0102, cleaned the intake screen of it's dirt build up, and now get P103.


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## 01Golf (Sep 30, 2008)

The thing about the MAF sensors is that its calibrated to your ECM/engine and an EBay one prob won't work that well for long. You might get lucky with one but the only way to properly replace a MAF sensor is to go to the dealer, give them your VIN and let them handle it. Yes they screwed up with doing mine but mistakes happen. Before i bought the dealer MAF i went to an auto parts store and bought one. Gave me more problems that I originally had so I bought the dealer MAF sensor. To the other guys w/ MAF codes, If your getting a MAF sensor code, don't dick around with grounds ETC... on it. Just replace it and stop complicating the problem LOL,


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## playsomehoops (Jul 14, 2004)

Thank for the info, maybe I can at least go to a VW specialist to save a few bucks instead of going to a dealer.


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## dkfackler (Feb 8, 2010)

01Golf said:


> Bringing this back from the dead. It turns out when my original MAF sensor died and I replaced it w/ am OEM one right from the dealer.....they gave me the wrong MAF sensor! Idiots! So I got the right one shortly after and its been running great now for the past 2 years! Just wanted to share!


Me, too. Same cause, too. Wrong MAF. Strange, though-- it ran fine for two years prior to this journey.


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## lunalife (Sep 28, 2015)

*I have the same code*

shoudld I bother cleaning it with sensor cleaner? On a p0103 code .. 01 jetta


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