Hi all i have a 307, yeah i no,. anyway i have just refilled the additive tank up. and conected my lexia to reset to zero, it wont or it says that the ecu did not responce,and could not comunicate with it,but it does with the rest of the car like abs esp etc etc,but just not that.will that be my additive ecu,fuse or somthing or my lexia3?. its reading codes from main ecu to say additve low.additive ecu ,and additvie level ecu. any help would be greatfull.. thanks inadvance