2018 Mercedes-Benz SL 3.0L Petrol · HD18 NKU

Two DVSA campaigns apply to these cars: R/2020/011, covering 5,255 vehicles, for engine emission output requiring improvement, with the engine control unit reflowed and the NOx sensor replaced where needed, and R/2020/243, covering a further 994 cars for the same work. Mercedes specialists describe the everyday consequence of this hardware: an AdBlue warning, a countdown stating the engine will not restart after a set distance, and eventually a car that will not re-start at all once the limit is reached, usually caused by a failed dosing pump, tank heater or NOx sensor rather than an empty tank.

DVSA campaign R/2018/268, dated 19 November 2018, covers 5,030 UK Mercedes cars built between 1 October 2017 and 30 April 2018 because the doors on the left-hand side can remain permanently locked after the car has been locked or unlocked with the remote key, with the affected door locks replaced as the remedy. UK recall data lists the campaign against Mercedes models of that build window, and for a driver who uses the passenger door in a tight parking space it is exactly the sort of fault that strands you. It is a free repair when the VIN qualifies, and an expensive one if it has already been ignored.