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:

    MAX COOL maximum cooling
    The MAX COOL function is only available in vehicles for the USA. MAX COOL is only operational when the engine is running. When you activate MAX COOL, climate control switches to the following ...

    DISTRONIC PLUS displays in the multifunction display
    General notes You can select the distance display in the Assistance menu  of the onboard computer. Display when DISTRONIC PLUS is deactivated •► Select the Distance Display functio ...

    General notes
    WARNING All categories of messages contain important information which should be taken note of and, where a malfunction is indicated, addressed as soon as possible at an authorized Mercedes-B ...