See also:

System self-test
After you have switched on the ignition, the system carries out a self-diagnosis. WARNING A malfunction in the system has been detected if one of the following conditions occurs: • the in ...

Purity
Assuring the purity of DEF is particularly important with respect to avoiding malfunctions in the exhaust gas aftertreatment system. If DEF is pumped out of the DEF tank, e.g. during repair wo ...

Cleaning the exterior lighting
Clean the plastic lenses of the exterior lights with a wet sponge and a mild cleaning agent, e.g. Mercedes-Benz car shampoo or cleaning cloths. Only use cleaning agents or cleaning cloths w ...