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:

    Problems with the navigation system
    Problem Possible causes/consequences and Solutions COMAND is unable to continue route guidance after the journey has been interrupted. Route guidance is canc ...

    Flat tire
    The "Breakdown assistance" section contains information and notes on how to deal with a flat tire. It also provides instructions on changing a wheel or mounting the spare wheel/emerg ...

    SmartKey
    0 To remove the SmartKey 1 Power supply for some consumers, such as the windshield wipers 2 Ignition (power supply for all consumers) and drive position 3 To start the engine The SmartKey can ...