# Air Intake Mass measurements



## TemeculaBug (Jun 11, 2012)

I'm trying to troubleshoot a P0171 CEL error on my daughter's beetle. 

I found the booster vacuum line to be bad (which I'm not sure if this could cause a P0171 error???). 

I also cleaned the MAF, but that didn't seem to help any. I hooked up a VAG-COM cable and used VCDS to analyze the Air Intake Mass values. 

According to Ross-Tech (click HERE) the Intake Air Mass values should be at the following: 

Idle: 2-4 g/s 
Max: 0.80 x HP (which should be around 90?) 

So, I ran my tests...at idle, redline in the driveway (in neutral), redline in 1st gear, redline in 2nd gear. Here are my results: 

Idle: 2.83 g/s (which is good) 
Max: 41.36 g/s (which I believe is too low) 

Does the 41.36 g/s value indicate a bad MAF, or is this value acceptable? 

Thanks! 
Gary


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## tdogg74 (Mar 1, 2002)

*FV-QR*

If you had a vacuum leak, then yea, that would cause a P0171 for sure. 

Idle seems normal, but you need to put load on the engine for a more accurate reading. Try doing a 3rd gear pull getting on the hiway. You should be able to get it up around 70-80 by the time you need to shift, and that should give VCDS more time and more rpms to give a better reading. 41.36 g/sec is far too low. Thats only about 51hp. You want to be reading around 90 g/sec. Do another run in a higher gear (more engine load) and bring it up as high as you (legally) can. 

If you are still experiencing a low g/sec number, replace the MAF. But I think your previous CEL was from the faulty booster line.


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## TemeculaBug (Jun 11, 2012)

Thank you very much for the reply - it really is appreciated. I'll give it a 3rd gear run today on the highway. I've ordered a new booster vacuum line, so we'll see if that clears the P0171. If it doesn't, I'll look at replacing the MAF. 

One more question: 
When I replace the vacuum line, do I need to clear the P0171 code or should it go away on its own (assuming that is the problem)? Does it take 3 successful runs, or 30 miles or ??? 

Thanks again, 
Gary


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## tdogg74 (Mar 1, 2002)

*FV-QR*

If you have VCDS, clear the codes manually.


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## TemeculaBug (Jun 11, 2012)

Thanks. Because I have to get it smogged, it will fail the readiness testing if I clear the code. I wanted to try and avoid putting it through an entire drive cycle, if it'll clear on its own. 

Thanks, 
Gary


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## greyhare (Dec 24, 2003)

http://www.ross-tech.com/vag-com/tour/readiness.html


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## tdogg74 (Mar 1, 2002)

*FV-QR*

It wont. 

Reset it and read this: 

http://www1.snapon.com/Files/Diagnostics/UserManuals/VolkswagenAudiReadinessCodeCharts.pdf


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## TemeculaBug (Jun 11, 2012)

Thank you both for the information. Very much appreciated!


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## TemeculaBug (Jun 11, 2012)

So, I've fixed the vacuum line (picked one up at the dealer)...cleared the light...and have driven it about 70miles. It's already passed 7 of the 8 readiness tests, and I haven't seen any error codes thrown :thumbup: 

So, thanks for all your help. I'm hoping the CEL won't pop up again, so I can get this smogged. It looks like I have a MAF replacement in the future also. 

Thanks!


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## Anony00GT (Mar 6, 2002)

If you have genuine VCDS, you have access to Basic Settings. You should be able to set all readiness monitors with VCDS (thereby also verifying your repair) right in the driveway, without driving an inch. 

Full VCDS has a readiness script you can follow. If using VCDS-Lite, refer to the appropriate repair manual for a list of Basic Settings to perform to set readiness.


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## TemeculaBug (Jun 11, 2012)

UPDATE and need more advice:

I replaced the bad booster vacuum line, cleared my CEL (P0171), and the same CEL code was thrown days later. So, the vacuum line didn't correct this issue.

I then purchased a new MAF (see my previous g/s flow numbers above). I was expecting my new flow numbers to be closer to 90 g/s. Unfortunately, the highest I've been able to get, is 58.08 g/s. 

So, while the numbers are better with this new MAF, it still seems low. I did revs at idle, 1st gear pulls, 2nd gear pulls and 3rd gear pulls. All to the rev limiter. 58 g/s is the highest I could get.

I cleared my CEL earlier today, and have put about 10miles on it. So far the CEL hasn't come back on, but I don't expect it to come on for a few more days as the readiness tests start to complete.

Any thoughts or advice on my flow numbers? I won't be so concerned, if the CEL just stays off (so I can get it smogged). 

Thanks again,
Gary


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## Anony00GT (Mar 6, 2002)

What type of MAF did you install?


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## TemeculaBug (Jun 11, 2012)

I ordered the Bosch one below (we have the AVH engine):

http://www.ecstuning.com/Search/Bosch_Mass_Air/ES6106/


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## TemeculaBug (Jun 11, 2012)

So, quick question for you all:

According to Ross-Tech, the flow rating should be 0.80 * HP. Is this HP the claimed crank HP from VW (115HP)? Or is it at the wheels with drivetrain loss?

I haven't found any other threads which show their flow numbers, so I'm struggling to understand what my numbers should be.

If they are low, what else could be the issue?


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## TemeculaBug (Jun 11, 2012)

I feel like an idiot, replying so much to my own thread - but oh well :screwy:

I've read elswhere, to measure block 032 as well. In the "free/limited" version, I was unable to do this. So, I paid the $99 and registered the lite version. 

Results of block 32...

BEFORE replacing the MAF:
(Lambda) idle: -2.8%
(Lambda) partial: +20.3%

AFTER replacing the MAF:
(Lambda) idle: +0.8%
(Lambda) partial: +3.1%

I believe anything over 10% (in the partial box), could indicate a bad MAF...correct? If this is the case, then my new MAF looks great compared to the old one. So, maybe I did end up needing the MAF afterall.


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## Anony00GT (Mar 6, 2002)

Much better with new vs old, for sure. Is this a genuine new Bosch or a reman Bosch?

Since you've got VCDS-Lite, post the whole scan, at least the engine part. Lets see what's going on.


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## TemeculaBug (Jun 11, 2012)

Thank you, Anony00GT.

The MAF sold wasn't supposed to be a remanufactured one, but I'll double check on this.

As for the engine scan, what are you looking for? Do you want me to measure a specific group (ie: 032) and report the log results? I know I can do an "Auto-Scan" of all the controllers. Is this what you're requesting?

Thanks,
Gary


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## Anony00GT (Mar 6, 2002)

Yes, the auto-scan to start. I'm really looking for the detail in address 01, but the whole scan may supply some necessary info.


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## TemeculaBug (Jun 11, 2012)

Here are the auto-scan results:


```
VCDS-Lite Version: Release 1.1
Friday, 29 June 2012, 14:45:54:56656


Chassis Type: 1C - VW New Beetle
Scan: 01,02,03,08,15,17,19,22,26,29,35,37,39,46,54,56,75
 
-------------------------------------------------------------------------------
Address 01: Engine       Labels: 06A-906-032-AVC.LBL
   Controller: 06A 906 032 BR
   Component: 2.0l R4/2V      G  *3654
   Coding: 00001
   Shop #: WSC 00066
   VCID: 6F918DEF3E93
No fault code found.
Readiness: 0000 1001

-------------------------------------------------------------------------------
Address 03: ABS Brakes       Labels: 1C0-907-37x-ABS.LBL
   Controller: 1C0 907 379 C
   Component: ABS FRONT MK60      0103
   Coding: 0004097
   Shop #: WSC 00066
   VCID: 2A275CFBC5F1
No Faults Found
  or DTCs not supported by controller
  or a communication error ocurred

-------------------------------------------------------------------------------
Address 15: Airbags       Labels: 6Q0-909-605-VW5.LBL
   Controller: 6Q0 909 605 A
   Component: 25 AIRBAG VW5  0E   0006
   Coding: 12853
   Shop #: WSC 00066
   VCID: 351D7F871C4F
3 Faults Found:
00591 -  Seat Belt Switch; Driver (E24)
            32-10 -  Resistance too High - Intermittent
01217 -  Side Airbag Igniter; Driver Side (N199)
            32-10 -  Resistance too High - Intermittent
00532 -  Supply Voltage B+
            07-10 -  Signal too Low - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments       Labels: 1C0-920-xx0.LBL
   Controller: 1C0 920 906 C
   Component: KOMBI+WEGFAHRS. M73 V03
   Coding: 03232
   Shop #: WSC 00000
   VCID: 2135BBD7B8C7
   Ident.-Nr. Wegfahrs.:VWZ5Z0A0161098
No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway       Labels: 6N0-909-901-19.LBL
   Controller: 6N0 909 901 
   Component: Gateway KCAN    V032
   Coding: 00006
   Shop #: WSC 00066
   VCID: F0930E93A3AD
No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv.       Labels: 1J0-959-799.LBL
   Controller: 1J0 959 799 AR
   Component: 7S Zentral-SG Komf. 0001
   Coding: 00256
   Shop #: WSC 00066
   VCID: 8E6F706BD959
2 Faults Found:
00943 -  Heated Exterior Mirror; Driver Side (Z4)
            35-00 -   -
00944 -  Heated Exterior Mirror; Passenger Side (Z5)
            35-00 -   -

-------------------------------------------------------------------------------
Address 56: Radio       Labels: Redir Fail!
   Controller: 1C0 035 180 E
   Component:  RADIO 3CP         0002
   Coding: 00403
   Shop #: WSC 00569
   VCID: 1A478C3B9591
1 Fault Found:
00853 -  Loudspeaker(s); Rear
            36-10 -  Open Circuit - Intermittent

End   --------------------------------------------------------------------------------------------------
```
My CEL is still off, from when I cleared it (after replacing the MAF). It has 2 more readiness tests to complete (SAI and Catalyst), so I'm hoping the MAF was my issue.

Thanks,
Gary


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## Anony00GT (Mar 6, 2002)

You can run those monitor tests with VCDS. Get it warmed up to an ECT of 90*F, then:

CAT:
01-04-046, hold 1800-2200 RPM until field 2 >440*, Field 4 will say TEST ON, continue holding RPM until test is completed ("CAT B1 OK")

NOTE: On some DBW cars, you can hold the brake pedal, then step on the gas and immediately click the "ON/OFF" button at the top of BASIC SETTING screen, the ECU will then hold the RPM where it's got to be for the test (~2000).

Then, return the engine to idle and:

SAI:
01-04-077, Field 4 will say TEST ON then display a result when completed.


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## TemeculaBug (Jun 11, 2012)

You've been very helpful Anony00GT - I really do appreciate it. I've read a few manual ways to set these readiness tests...but it was never clear. Your instructions above, seem very straight forward. I'll give it a try!

Thanks,
Gary


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## TemeculaBug (Jun 11, 2012)

I must either be an idiot or I'm doing something wrong. I went into 01-04-046 (under basic settings) and my RPMs immediately drop to idle. My gas pedal no longer works when I'm in 01-04-046.

I do not have an ON/OFF button like this either:

http://www.ross-tech.com/vcds-lite/manual/basic.html

I'm currently on Ross-Tech's website, trying to understand why I don't have the ON/OFF button within Basic Settings.


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## TemeculaBug (Jun 11, 2012)

This is what I'm talking about. You'll notice in the image below, that there is no ON/OFF button:


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## Anony00GT (Mar 6, 2002)

45*? Are you doing this on a cold engine? Is the ECT above 90* like I said earlier? The car has to be full operating temp for any tests to run.

Also, type in 046 and click GO, then bring the RPM up. Not before.

As for ON/OFF/NEXT, it's not always there, that's normal. Depends on the module. Here's the explanation from Ross-Tech:



> [Switch to Meas. Blocks] will switch back to the passive (and "safe") Measuring Blocks mode. On Controllers using KWP-2000, that button is not available but instead there may be an [ON/OFF/Next] button that allows you to initiate and exit Basic Settings while still being able to see the values in the measuring groups. This does not appear every time and it's appearance and function are up to each controller in the car.


Without that button, just hold 2000-2200 RPM and field 4 will change to TEST ON when it's ready to run.


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## TemeculaBug (Jun 11, 2012)

I had the car running for a good 10 minutes. Engine temp was around 97deg C. I was showing the Catalytic Converter Temp in group 34, over 400deg C. 

When I tried to run the test, I typed in 46...car at idle...hit GO. Unfortunately, once I hit go...giving it gas does nothing. I wasn't giving it any gas until after I hit GO.

Either way it sounds like box 2 needs to be much hotter (90+) as you mention. So, I'll go back out and wait for that to show 90 and retest.

Thanks,
Gary


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## Anony00GT (Mar 6, 2002)

If it won't let you achieve 2000 RPM in that basic setting, let it idle for awhile and see what happens.

That's odd though, let me check something real quick. What is the year of the car and engine code you're working with here? The scan says AVC in the label file, but I have a feeling that's not right.


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## TemeculaBug (Jun 11, 2012)

So...I just went out and tried it again. The second I hit "Go", I can no longer use the gas pedal. My temp peaked at 485* this time...but still nothing. I tried everything, and let it idle for over 5mins before pressing the gas.

You are correct! I do NOT have an AVC. Ours is AVH. I'm assuming I can change that in "Options". Let me try changing the engine code, and trying again!

Thanks,
Gary


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## TemeculaBug (Jun 11, 2012)

I couldn't find anywhere in the program, where I could specify my engine code. 

Please don't spend any more time on this. You've already been more than helpful! It seems so straight forward, yet something is just not right. The odd thing, is that the gas pedal responded for a brief 2-3 secs...then it completely stopped responding again.

I'm taking my daughters to a concert tomorrow night, so I'll be able to put on quite a bit of miles. Hopefully it'll set the readiness tests from all the driving.

Thanks again for all your help,
Gary


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## Anony00GT (Mar 6, 2002)

Did you try doing the brake and gas thing? IIRC, AVH is capable of that.

Also, there may be a problem preventing the test from running. Check for codes again after your trip, CEL or not.


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## TemeculaBug (Jun 11, 2012)

Thanks. I'll check for codes tomorrow morning. I did try the brake/gas thing, and that didn't work either. 

Side question:
How do I change the program to use the correct engine code? Is it possible, or does the program auto-detect it?


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## Anony00GT (Mar 6, 2002)

It doesn't matter, and there's no way to input it. The program just reads the module information. The label files don't always correspond to the actual engine code, so no big deal.

I did verify that the gas/brake thing should work on AVH though, that's the way to do it. I'm thinking you've still got a problem that's causing the test to not run. Were any codes thrown after the test didn't run?


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## TemeculaBug (Jun 11, 2012)

I checked for codes, and there were none thrown. I'll wait until tomorrow, after our long drives. Hopefully that'll set everything to ready.


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## TemeculaBug (Jun 11, 2012)

After our long trip to the city last night, all my readiness codes were set to READY. I do not have the CEL I had before. I did another full car scan, and there are NO engine errors thrown.

I'll drive it around today a bit, but it looks like the MAF was my problem (and the bad vacuum line wasn't helping). 

Anyway, I appreciate everyone's help!

Thanks,
Gary


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