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 work, it must not be returned to the tank. The purity of the fluid can no longer be guaranteed.

service products, cleaning agents or dust) Impurities in DEF (e.g. due to other service products, cleaning agents or dust) lead to:
• increased emission values
• damage to the catalytic converter
• engine damage
• malfunctions in the BlueTEC exhaust gas aftertreatment system

    See also:

    Before changing a fuse
    •► Park the vehicle and apply the parking brake. •► Switch off all electrical consumers. •► Remove the SmartKey from the ignition lock. The fuses are located in various fuse b ...

    Displays and controls
      ...

    Engine number
    1 Emission control information plate, including the certification of both federal and Californian emissions standards 2 Engine number (stamped into the crankcase) 3 VIN (on the lower edge of ...