To those who have installed or will install VW MAFs..... - The Unofficial BMW M5 Messageboard (m5board.com)

Tozzy · 10th August 2007, 00:47

I bought the VW MAFs with partnumber: 06A906461 and was very happy with the extra power and smothness i got. But someone told me that the VW MAF's do not have a intake air temperature sensor, as the BMW MAFs have, so I checked my VW MAF's and they don't have the temperature sensor. When checking for errorcodes I found a errorcode for Intake Air Temperature sensor Performance. Maybe this is why some of you get the SES light after replacing the MAF's with VW ones?

Anyway, I figured out how to fix this issue by transfering the temperature sensor from the "bad" BMW MAF to the new VW MAF and it fixed the errorcode since the DME/ECU is getting correct IAT signals now.

I did some research in WDS to see how the sensor is connected inside the MAF and the sensor is directly connected to the pin1(signal) and pin3(ground) and the VW MAF has the connectors for IAT in place but not the sensor.

Obviously this does not apply if you have a IATS kit installed since IATS disconnects the temp sensors in the MAF.

I made a small DIY webpage on how to fix this issue here: http://tozzynet.se/BMW/VAG-BMWmaf/maffix.htm

Hope this helps someone

/Thomas

SeeSure · 10th August 2007, 01:16

Good information - thank you

alquazi · 10th August 2007, 01:19

Thanx for the info.
I've been running VW MAF's with no problems, but will check for error codes

M5CCIE · 10th August 2007, 01:37

Thank you. This is great info. Was there a way to get the sensor through the plastic holder hole so we won't have to use any soldering?

This should be a sticky!

Blockdoc · 10th August 2007, 06:42

Hi Tozzy,
Thanks for the info! What kind of software are you your computer?

Any thoughts on the function of the temp sensor as far as performance. In other words...I installed the VW MAFs about 5000 miles ago and have had no SES codes. In the absence of fault codes, would you speculate that the absence of the sensor has any effect on performance (in moderate climate)??

Brian

SeattleM5 · 10th August 2007, 08:02

Interesting. Thanks for the write up and the great photos. I'm a bit confused, however. I purchased a set of VW MAFs (part# 06A906461A) a little while ago but haven't gotten around to installing them yet. After reading your post I took a peek at mine (still in the original VW housing) and it seems that they have the temp sensor in place. Wonder why some have the sensor and some do not?

Tozzy · 10th August 2007, 09:58

Quote:

Originally Posted by M5CCIE

Thank you. This is great info. Was there a way to get the sensor through the plastic holder hole so we won't have to use any soldering?

This should be a sticky!

The "plastic holder" on the VW MAF is open so there is no hole.

You could probably use some kind of glue instead, since it is not near any electronic parts I don't think there is a risk but if you use the wrong kind it could fall off and go inside the engine which could be bad.

here is a close up compare pic before i did any changes:

ReflexGTI · 10th August 2007, 10:20

The later VW MAFS have the IAT sensor built in so it looks like you might have bought the earlier VW MAFS instead.

Tozzy · 10th August 2007, 10:25

Quote:

Originally Posted by Blockdoc

Hi Tozzy,
Thanks for the info! What kind of software are you your computer?

Any thoughts on the function of the temp sensor as far as performance. In other words...I installed the VW MAFs about 5000 miles ago and have had no SES codes. In the absence of fault codes, would you speculate that the absence of the sensor has any effect on performance (in moderate climate)??

Brian

The software I use is ProScan 5 but most OBD II software can display the sensor info.

I haven't noticed a big difference in performance after the changes but then I have only done a couple of testdrives since then. It feels really strong and smooth so it's hard to feel minor changes in performance and I still have to get used to the "new" power

. If you do not have any faultcodes you probably got the VW version with a tempsensor see SeattleM5's post.

By "No SES Codes", do you mean that you have not got the SES light or have you checked with a computer? I did not get a SES light but found faultcodes with Proscan.

I believe that if the DME sets the IAT tempvalue to a "default/safe mode" 140 degrees in the abscence of a temp sensor it should affect mpg and probably performance to some degree since ignition timing and fuelinjection use this to calculate changes.

/Thomas

Tozzy · 10th August 2007, 10:35

SeatleM5, ReflexGTI

It seems odd that there would be a difference if the partnumber is the same. even if there is a difference between euro spec and US spec MAF's or old version/new version they should have different part numbers?

fishy....