Maff sensor fault ?

**ScouseNinja** · 12-09-2008,06:17 PM

First off let me say Hello to all from a new member

who is in desperate need of some

Looking at this image taken frommy vag com conection I would say my maff is faulty judging by the out of spec values in field 3 , can anyone confirm it ?

Or am I missunderstanding what the readings mean ?

BTW The car is an A4 1.9TDi Avant 1999 , its a right bag a poo lol , Its unable to break free from a wet paper bag !

Please help me

Thanks all

**smokey0123** · 12-09-2008,06:22 PM

Try taking it for a drive with the AMM (MAF) disconected.

**ScouseNinja** · 12-09-2008,06:42 PM

I already tried it

, There is no change with or without the sensor

which makes me think even more that its gone , just didnt want to spend loads of cash without someone else thinking the same as me

**smokey0123** · 12-09-2008,06:46 PM

Is it showing any fault codes?

**olds_kool** · 12-09-2008,06:49 PM

if it runs better with maf disconnected does it mean maf is faulty? my tdi seems to pull better with maf unplugged but not sure if this means its faulty or not

**ScouseNinja** · 12-09-2008,07:11 PM

It was showing codes (but not maff related )
The codes I had where

1. Alarm horn - not comunicating
2. CL Pump - Over run (im looking into a new pump as i think the impellor has failed)

and several other"alarm activated" codes which presumabley I have stored whilst trying to get my doors to lock and alarm to work. I have cleared all codes and will check em again tomorrow for new ones after work am also thinking of letting my laptop run under the seat on the way to work and letting it log the jourey for later review.

Im not sure but if there is no change or an improvment with maff disconected then there is a problem with the maff. If it runs worse then your maff was good. but again im not certain which is why im looking at the live data from vagcom to try and clear it up. I have an gnvq lvl3 in auto mechanics but never realy did much work with diesels or modern engines

so am lacking experience lol

**olds_kool** · 12-09-2008,07:39 PM

according to ross tech car needs to be moving to get usable results for maf

http://www.ross-tech.com/vag-com/cars/tdi.html

your fault codes are from 35 central electrics? non stored for engine?

**smokey0123** · 12-09-2008,07:52 PM

We need to know if there is any codes stored in 01 engine. Can you hear the turbo working?

**ScouseNinja** · 12-09-2008,08:04 PM

Originally Posted by olds_kool

according to ross tech car needs to be moving to get usable results for maf

http://www.ross-tech.com/vag-com/cars/tdi.html

your fault codes are from 35 central electrics? non stored for engine?

Cheers for that linky , ill try that tomorrow .

No there are absolutly no codes in th 01 engine section

, errm the turbo - I used to be able to hear it quite well with the window open at low speeds but it does seem to have gone quiter than it was although still audible.

**ScouseNinja** · 13-09-2008,03:21 PM

Today I changed the maff , no change.

I have found a split in a vac pipe though, its the one between the maff and the turbo (has a beather going upto the oil filler cap on the rocker cover) the split is at the joint between the large pipe and the breather just before the turbo.

I also have a fault code now that didnt show up before,

17958 - charge presure: control deviation
P1550 - 35 - 00 - -