[Biturbos4] driving without working MAF

Andy Turner andy at palomar.demon.co.uk
Fri Jul 23 07:55:50 EDT 2004

I've advocated for a while that VAG-COM should allow for plug-in
software modules. That would allow someone to write a MAF test plug-in
that retrieved the relevant values, made the calculations and gave a
diagnosis - perhaps in line with the guidelines that Andy @ Ross-tech


On Fri, 23 Jul 2004 07:35:21 -0400, David Kavanagh <audiguy at gmail.com>

>FYI. I checked for codes again last night. None, but the block 32
>values (fuel trim) were
>-4.5% 15.6% -4.7% 16.4%
>The higher numbers are the multiplicative fuel trim. They adjust
>higher RPM trim and values > +/- 10% indicate a MAF that is out of
>whack. (the lower values are the additive fuel trim and values > +/-
>10% would indicate a vacuum leak).... that info from Andy at Ross-Tech
>(at the link provided below)
>So, I'll just have to wait for it to get bad enough to throw codes
>that cause the CEL (or MIL if you are persnickety) to come on.
>On Thu, 22 Jul 2004 00:54:39 -0400, David Kavanagh <audiguy at gmail.com> wrote:
>> This link should provide a bunch of info for checking the MAF and
>> understanding how the ECU tries to correct via fuel trim.
>> http://forums.vwvortex.com/zerothread?id=1201806
>> I just checked my codes again tonight (after resetting a couple days
>> ago) and got.
>> 2 Faults Found:
>> 17538 - Fuel Trim: Bank 2 (Mult): System too Lean
>>         P1130 - 35-10 - - - Intermittent
>> 17536 - Fuel Trim: Bank 1 (Mult): System too Lean
>>         P1128 - 35-10 - - - Intermittent
>> I forgot to check measurement block 032 (which would have told me how
>> much the ECU had to correct for the MAF) I'll check those next time I
>> see these codes.
>> BTW, I have a '00 A6 2.7t 6-speed... (wouldn't mind an S4 though!)

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