P0103 code Passat 2003 AWT engine

KimAndersen · Post by **KimAndersen** » Wed Oct 11, 2017 7:15 pm

Bjorn - The outcome of your maf testing will show you what direction you should take. The maf sensor output voltage can be higher than 5 volt as seen in my case study here !!!

https://www.picoauto.com/library/case-s ... ass-sensor

Regards
Kim

Technician · Post by **Technician** » Wed Oct 11, 2017 7:46 pm

Hi Tronic,

have you removed the MAF sensor and checked it for being clean?
Has the vehicle been run with no air filter installed?
While running the engine try tapping the MAF sensor with the handle of a screwdriver and see what happens!!
While the scope is connected of course

Tronic · Post by **Tronic** » Wed Oct 11, 2017 8:53 pm

Hi Technician! Long time no see!

No, have not tried any of what you wrote, but I will keep those suggestions in mind for the future. Why I did not, well ... I was thinking that a dirty MAF would not give high air mass readings and besides, it was rock steady at 240g/s at idle - how that could be with an engine with smooth idle and perfect fuel trims!

Knocking with a screwdriver may have pointed me to internal faults, but have not had much time to work on cars lately because at present I am the only technician at the school and we use to be two ... Technician, a scope is my daily partner, but 90% of the time my bench scopes are doing the job, not the excellent Pico.

Tronic · Post by **Tronic** » Wed Oct 11, 2017 9:02 pm

Very nice write up Kim, interesting reading and excellent job done!!

I will, as I wrote earlier, hook up the scope, so lets see what findings I get. Absolutely that was indeed high signal from your MAF

However, a fully functional MAF will stay well below the 5 volt supply - its headroom so to speak - so any reading above will then point to MAF internals or wiring. Thanks Kim for all input and help, I will be back.

Regards

Bjorn

Tronic · Post by **Tronic** » Thu Oct 12, 2017 1:56 pm

So ... here is the outcome of my MAF testing. Picture speaks by itself.

Regards
Bjorn

Technician · Post by **Technician** » Thu Oct 12, 2017 6:33 pm

Hi Tronic,

Any chance you can post up the live scope data rather than a screen shot

I'd like to have a closer look please

Tronic · Post by **Tronic** » Thu Oct 12, 2017 6:50 pm

Of course Technician! I will, but I post the psdata files tomorrow because they are in my computer at work

KimAndersen · Post by **KimAndersen** » Thu Oct 12, 2017 7:06 pm

Bjorn - That's a very high output voltage you got there.
No wonder that ecu get a high reading in terms of gram per second (g/s).

Regards
Kim

RYM6746 · Post by **RYM6746** » Thu Oct 12, 2017 7:22 pm

Did you test the sensor ground? Does the signal wire voltage disappear when you unplug the MAF? If the answer to both questions is yes you are done it needs a MAF.

Tronic · Post by **Tronic** » Thu Oct 12, 2017 9:33 pm

Kim

That would be a hell of an engine to suck 240g/s at idle! So from now, I am the leader in the competition "highest voltage at MAF signal output".

Thanks Kim for all the help!

Regards
Bjorn

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