Fitted a new egr valve , plug looked ok ,pins ok , still have egr code po 40300 and showing no live data , I need to check pins next but is there anywhere that the wiring rubs or breaks ect

What year is the car and which engine type does it have?

It's 2012. ,1.2 TDI ,new egr fitted but still has same code and glow plugs light flashing,I was going to find out what voltage I think should be 5 v at which pin , and wanted to know iif there was a common place wiring may be damaged