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:

    Under the Hood
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    Resetting the side windows
    You must reset each side window if a side window can no longer be closed fully. Close all the doors. Turn the SmartKey to position 1 or 2 in the ignition lock. Pull the corresponding switch ...

    Problems with your vehicle
    If you should experience a problem with your vehicle, particularly one that you believe may affect its safe operation, we urge you to contact an authorized Mercedes-Benz Center immediately to ...