16846 - Mass air flow sensor - Signal too low

[Wullyc]

Hi, had this code for a few months now.
VCDS says
Mass Air Flow Sensor
P01012 000 - Signal too low

other than the engine management light the car runs absolutely fine. I probed the MAF plug and here are the results for a 5 pin BOSCH 
plug.

Engine off
Pin 01 - empty
Pin 02 - 0.05v
Pin 03 - battery voltage (fine)
Pin 04 - 4.94v or 6.93v if I swap polarity
Pin 05 - battery voltage (fine)

engine running
Pin 01- empty
Pin 02 - 1.4v idle
Pin 03 - battery voltage (fine)
Pin 04 - 4.94v or 9.22 if I swap polarity
Pin 05 - battery voltage (fine)

couldn’t Rev the car to see if pin 02 increases idle but I believe so as I could see it fluctuating.

using measuring block 010 on vcds it says MAF is 550mg/str. It doesn’t move at all. I have no codes for EGR. I believe the egr valve is functioning. I can hear the valve when I start the egr basic settings test. I cleaned it out last weekend as well there was tonnes of black sludge no suprise. 

I clear the code and the fault in vcds immediately comes back onBut EML/MIL light won’t come back on until car is restated.



Bit confused don’t really know what to do next. I’ve uploaded a screenshot of a graph, as you can see. Red line is MAF and completely dead. Yellow is egr it appears to be working. Green is intake temp doesn’t fluctuate but not sure if it does. It did measure 5 deg c Then 6 deg c minute later however. The reason I included the egr and intake air temp is because I believe the egr can affect the MAF. I also believe the intake air temp is part of the MAF?