Megane P0722 Low input warning

My replacement 2004 1.9 DCi Megane for has been a bit of a problem child since I got it. It’s had a number of error codes showing including Glow plug relay which turned out in the end to be broken wire and PO487 error code which resulted in me replacing the ERG valve as it came apart when I tried to remove it.



I have one ‘pending’ fault showing now ‘P0722 PowerTrain Output speed sensor circuit low input’ What is where is it and what does it do?



Len