Mercedes c class coupe filled adblue up as normal as showing low. Couple days later engine light on and can not start in 400 miles RAC altered this adding miles on for me, engine loght appeared and booked in at dealership however light when off and told me to go to mercedes. If I has the adblue disabled how does that work for MOT and Service? Only a short while that it will return on the car again and knowing theres a full tank in there