UKPassats

I’m pulling my hair out and need some advice. Took car for MOT couple of weeks ago and knew it would fail as engine warning light was on. Plugged it into computer to find egr malfunction. After shopping around bit the bullet and formed out £485 to get it changed and get it through test. Now the light is back on so plugged code reader in and comes up with code P0403 egr a control circuit open. What does this mean. It’s had a new egr so can’t see what the issue is.
Passat sport 2011 2.0tdi if that helps.