Adblue/NOx Sensor recall

[paulie1969]

Hi all. My W205 had the Adblue /NOx Sensor recall outstanding. I checked with my local dealer and they got it booked in. On collecting the car, as soon as I started it the EML lit up. I went back in & they said it needed a DPF Regen. 2 hours later they tell me the regen failed & they had to do a tech enquiry to MBUK. I get a call the next day saying the adblue relay in the boot is missing & there had been a previous wiring repair? They ordered the relay & the EML still will not clear & they now want to charge me for the "wiring repair". Would the missing relay bring up the EML immediately it is removed, as there was never an EML light on before I took the car in for the recall. Wouldn't the recall process detect the relay was missing before updating the software or running the diagnostic process? Any advice or info appreciated!