General notes

If you cannot lock or unlock the vehicle with the SmartKey, either the battery in the SmartKey is discharged, the SmartKey is faulty or the starter battery is discharged.

replace it if necessary. Check the battery in the SmartKey and replace it if necessary.
mechanical key. Unlock the driver's door using the mechanical key.
Lock the vehicle.
contacts checked at a qualified specialist Have the starter battery and the battery contacts checked at a qualified specialist workshop.

If the SmartKey is faulty, contact Roadside Assistance or a qualified specialist workshop.

    See also:

    Activating/deactivating PRE-SAFE® Brake
    PRE-SAFE® Brake is only available in vehicles with DISTRONIC PLUS. Press the or button on the steering wheel to select the DriveAssist menu. Press or to select PRE-SAFE Brake. Pres ...

    The mbrace system
    The mbrace system provides different services, e.g.: • automatic and manual emergency call • Roadside Assistance call • MB Info call To adjust the volume during an mbrace call, proceed as foll ...

    BAS PLUS (Brake Assist System Plus)
    BAS PLUS is only available in vehicles equipped with DISTRONIC PLUS. Observe the "Important safety notes" section. At speeds above approximately 20 mph (30 km/h), BAS PLUS assists ...