Hi, I have had the dreaded 'No restart in 650 miles' due to an adblue issue.  We know it's electrical and I assume it will mean a new module.  As with many, things are tight so thinking of getting a used part.  The code is 4M0907355.  When i have searched however, there seems to be a letter at the end, either a D or E, and i think i spotted a G.  Does anyone know what that means.  I have a 2016 Audi A4 Sline Diesel.  

Also, any ideas how much it would cost to fit the part when i have purchased it?  

Thanks Dan

I have the same problem - Audi part is 700 odd just for the unit. My local garage (not Audi) have said they’re not sure a second hand unit can be used as it will need to be programmed to the car directly. Has anyone used a second hand unit or know if the current unit can be repaired? 
 

Thanks,

 

Joe 

I'd speak to an auto electrican or Audi independent garage.