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.

Impurities in DEF (e.g. due to other 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:

    Important safety notes
    Observe the "Important safety notes" section. ABS regulates brake pressure in such a way that the wheels do not lock when you brake. This allows you to continue steering the vehic ...

    Mounting a new wheel
    WARNING   Always replace wheel bolts that are damaged or rusted. Never apply oil or grease to wheel bolts. Damaged wheel hub threads should be repaired immediately. Do not continue to ...

    Resetting the panorama roof with power tilt/sliding panel and the roller sunblinds
    Reset the panorama roof with power tilt/ sliding panel and the roller sunblinds if the panorama roof with power tilt/sliding panel or the roller sunblinds do not move smoothly. •► Turn th ...