# Trying to pass emissions (P0103).



## prophylactic (Mar 5, 2007)

*Car:* 1998 Jetta GTL, 2.0.
*Problem:* P0103.
Okay, I tried asking this question in another forum, but was rewarded with nothing but snide, meaningless comments. The problem: P0103. I replaced the MAF, to no avail, with a new one yesterday. It is possible, I suppose, that the sensor that I bought could be bad, too, but I'm too new to VW to really diagnose and or figure things out without any input. I've reset the CEL with my scanner a few times after replacing the sensor, but it keeps coming back. So, yeah, if anyone knows what I'm talking about, I'd appreciate some help.


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## prophylactic (Mar 5, 2007)

Can anyone help me? I'm looking for a way to get this fixed soon. I don't know if I have a bad MAF, or if there's something before it in the circuit that's tripping it in such a way as to cause the P0103 code. 
At this point, I'm thinking I have a bad MAF, even the new one; however, I'm not sure how to really test this. If anyone could help me, I'd really appreciate it.


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## Mr.VR6 (Jan 27, 2003)

*Re: (prophylactic)*

Come on guys someone help this dude out. He got nothing but smart AZZ comments in the MK3 forum by nothing but AZZ HOLES.







http://****************.com/smile/emthup.gif


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## $cash only$ (Jan 23, 2007)

*Re: (Mr.VR6)*

Might want to try cleaning it also what you should do is disconnect your batt for like 15min then connect so your car can learn off of the new part..... just a few ideas. If none of that works try to get a voltage reading and look up in a bentley what it should be at. People on here will go through 3-4mafs before they realize its something to do with the circuitry. http://****************.com/smile/emthup.gif GL


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## prophylactic (Mar 5, 2007)

It's a new MAF -- I don't think it needs cleaning already? I'm wondering, however, if it's just a bad one? I've tried disconnecting the battery countless times, and I've also cleared it with my OBD II scanner. The voltage at the plug itself (with the MAF disconnected) is 14V and the other is 12V, as it seemed. 
Really, what I'm hoping is that someone will be able to tell me what will cause the MAF to throw that code if it's not the MAF itself. I'm not familiar with Bentley's site, however. 
One peculiar thing that still leads me to believe that I have a bad MAF, even after replacing it, is that whenever I unplug it entirely and start the car, the car runs better without it. New or old. This seems to indicate that I was, in fact, sold a bad one? Like I've said, I'm far too new to VW to really figure things out without possibly spending far too much.


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## Mr.VR6 (Jan 27, 2003)

*Re: (prophylactic)*

Bump!!!







http://****************.com/smile/emthup.gif


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## prophylactic (Mar 5, 2007)

Does anyone have any ideas here? Someone has to have had this code before? I don't particularly want to go to Volkswagen to have this serviced; thus far, they've proved themselves to be pompous and unhelpful. Oh, and naturally, expensive. 
Being that the car runs better with no MAF at all, even when I plug the new one in, should this necessarily imply that the new one is junk, too? Or what? Someone has to have more information about this, I'd hope.


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## PeruEuro (Dec 28, 2006)

o2 sensor? What are the symptoms?


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## prophylactic (Mar 5, 2007)

Hard starts, and once in a while it will randomly die when I come to a stop. The other symptom, of course, is that I can't pass emissions with the code. Could an O2 sensor cause things along these lines?
I have to give it a little bit of gas when I start it. After that, it usually runs well.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (prophylactic)*

Have you checked plugs, wires? Is it misfiring?


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## PeruEuro (Dec 28, 2006)

Check timing, spark, fuel. then see if t heres a bird your air intake.


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## bearing01 (May 27, 2004)

*Re: (PeruEuro)*

DTC P0103/16487 - MAF CIRCUIT HIGH INPUT
NOTE: DTC is set when signal from Mass Airflow (MAF) sensor to
Electronic Control Module (ECM) is too high.
1) Inspect MAF sensor connector for looseness and/or
corrosion. Repair sensor connector as necessary. Erase DTC memory and
test drive vehicle. See CLEARING DTCS in this article. Recheck DTC
memory and verify DTC does not reset. If DTC resets, go to next step.
If sensor connector is okay, go to next step.
2) Check MAF sensor fuse. Replace if necessary. Turn ignition
off. Disconnect MAF sensor connector. Disconnect ECM connector.
Connect Test Box (VAG 1598/18) to ECM wiring harness. Terminal
assignments of test box are identical to ECM connector's.
3) Using a DVOM, check resistance between MAF sensor
connector terminal No. 1 and test box socket No. 1. Jumper MAF sensor
connector terminals No. 1 and 2, and check resistance between test box
sockets No. 1 and 16. Jumper MAF sensor connector terminals No. 1 and
4, and check resistance between test box sockets No. 1 and 17.
Resistance should be less than 1.5 ohms. If resistance is as
specified, go to next step. If resistance is not as specified, repair
open circuit between MAF sensor connector and ECM. Erase DTC memory
and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC
memory and verify DTC does not reset. If DTC resets, go to next step.
4) Remove jumper and check resistance between test box
sockets No. 16 and 17. Resistance should be infinite (no continuity).
If resistance is as specified, go to next step. If resistance is not
as specified, repair short circuit between MAF sensor connector and
ECM connector. Erase DTC memory and test drive vehicle. See CLEARING
DTCS in this article. Recheck DTC memory and verify DTC does not
reset. If DTC resets, go to next step.
5) Replace MAF sensor. Erase DTC memory and test drive
vehicle. See CLEARING DTCS in this article. Recheck DTC memory and
verify DTC does not reset. If DTC resets, go to next step.
6) Replace faulty ECM. Test drive vehicle. Recheck DTC memory
and verify DTC does not reset. If DTC resets, repeat testing
procedure.

There's also a technical service bulletin :
Model(s):Golf, Jetta, Passat, w/ Eng. codes ABA, AAA
Cabrio w/Eng. code ABA
EuroVan with w/Eng. code AES
Subject: DTC’s P1580 (17988) and P0103 (16487) Stored in DTC Memory
Group: 01
Number:99--18
Date: 1996 ä 1999 Oct. 29, 1999, 
1997 ä 2000
Condition
Diagnostic Trouble Codes (DTC’s)
P1580 (Throttle Actuator B1 Malfunction) and
P0103 (Mass or Volume Air Flow Circuit High
Input) are stored in DTC memory
simultaneously.
May be caused by an attempt to start a
vehicle with a dead or low charged battery
(below approx. 7V).
These DTC’s predominately show up together
on a vehicle with a low charged or dead
battery (can occur at PDI if battery is not
maintained).
Service
If an attempt is made to start a vehicle with a
battery charge at approx. 7V (or lower):
DTC P1580 (17988) will be stored in DTC
memory.
Once DTC P1580 (17988) is stored:
If the vehicle is then jump started and driven,
the second DTC, P0103 (16487) will then be
stored.
Note:
Throttle valve angle (when checked in “Basic
setting” Function 04, display group 098) will be
“0” in any throttle valve position.
Once these DTC’s have been stored in DTC
memory the following applies:
If DTC’s are erased and throttle body
adaptation is not performed, both DTC’s will
be stored again in DTC memory immediately.
If throttle body adaptation is performed
(without erasing DTC’s) “error” will be
displayed on the VAG 1551 Scan tool in
Display Group 098.
In both cases vehicle may not start or may run
poorly.
DONOT replace any parts for this condition,
perform the following steps:
The following must be performed IN
SEQUENCE to remove stored DTC’s P1580
and P0103:
D Battery condition must be OK.
-- Charge and/or replace battery according to
procedures in latest version of VESIS,
Group 27.
With battery condition OK:
-- Connect VAG 1551 Scan Tool.
-- Erase any stored DTC’s.
-- Perform Throttle Body Adaptation (see
appropriate Repair Manual).
-- Erase stored DTC’s again.
-- Set readiness code.
Also see Technical Bulletin 01--99--15 which
deals with procedures to follow after power is
interrupted.


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## prophylactic (Mar 5, 2007)

I only have the one code, so I don't think the lower portion applies to me. I'm not sure, however, which fuse is for the MAF sensor?


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## Mr.VR6 (Jan 27, 2003)

*Re: (prophylactic)*

I will give a bump for this dude. http://****************.com/smile/emthup.gif 
Come on guys help him out. CELs are one thing that get on many peoples azz and it takes them to hell just looking at them while driving.


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## prophylactic (Mar 5, 2007)

I'm still having this problem. I'm not sure how to fix it, and Volkswagen, and or like Volkswagen shops, want between $60-$120 just to tell me what the problem is. Yeah, somehow, I don't think that's necessarily worth it, as I'll still have to fix it, after that. So, in effect, if anyone could help me out here, I'd appreciate it. 
I don't think I have any electrical problems. I noticed a bad vacuum hose today, and I fixed it. However, this did nothing for the code. My plugs and wires are new, as is my MAF and air filter. Could this be EGR, or somehow, still a bad MAF?


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## bearing01 (May 27, 2004)

*Re: (prophylactic)*

If you can give the HCppm, CO%, CO2% and NOx% readings from the smog test I can tell you what is causing you to fail smog.
Do you have continuity between all the pins on the MAF sensor and the ECM?


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## prophylactic (Mar 5, 2007)

I'm not sure what the percentages are. What's your suggestion, anyway? Where is the ECM located in this car? 
I can re-read the code with my OBD II scanner, and get you the exact aspects of emissions the car thinks it's failing, if this would help?


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## bearing01 (May 27, 2004)

*Re: (prophylactic)*

Of course, any info you can provide will help solve the problem.
If you knew the emissions content in the exhaust pipe then form that we could tell if the car is running lean or rich... that is... if they did a tail pipe probe and that's why you're failing. If you have a CEL then you'd also fail from that. I didn't know if you had the numbers on hand and just never posted them.
Did you check the continuity of the MAF connector to the ECM?


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## prophylactic (Mar 5, 2007)

No, I don't have the numbers; they didn't do a tailpipe probe -- they only plugged my car in and immediately read the code. My scanner provides limited information on the smog issues. I'll scan it again, and post whatever it provides. 
As far as testing continuity between the MAF and the ECM, I'm honestly not sure where the ECM is (very, very new to VW, by the way).


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## prophylactic (Mar 5, 2007)

One thing that still strikes me as exceptionally peculiar is that it runs better with the MAF completely disconnected -- new or old.


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## bearing01 (May 27, 2004)

*Re: (prophylactic)*

Unplugging the MAF makes the car run in a "limp home" safe operation mode. Because all sensors are not available for the computer determine optimal operation settings, the computer will make air/fuel rich to make sure the car is drivable and won't cause detonation & damage itself. For example, if you're running lean because the MAF is out of wack, unplugging it will get the car to run a little rich and improve drivability compared to when you were running lean.


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## prophylactic (Mar 5, 2007)

I think the computer is actually what's bad, at this point. I re-ran the wires to the ECU from the MAF sensor. This changed nothing. There are no other codes available to be read, and I've changed the MAF sensor. It seems almost invariable that the computer is at-fault. Any input?


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## OrangeDUB (Sep 18, 2006)

*Re: (prophylactic)*

Similar problem to yours was just solved on my vr by getting a new maf. Also I would also change your pre-cat sensor.
I wouldn't mess with your new maf sensor (don't clean it). Down the road you can clean it with contact cleaner if you feel the need to, it's available at radioshack. 
The maf and 1st o2 sensor play key roles in your a/f mix, and I think the maf is ruled out as not being the cuiprit.








PS Golf = GTI Jetta = GLI


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