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.

SmartKey and 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.
mechanical key. Lock the vehicle using the mechanical key.
battery contacts checked at a qualified specialist workshop. 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:

    Vehicles with automatic transmission
    Apply the parking brake firmly. Shift the transmission to position P. Using the SmartKey Turn the SmartKey to position 0 in the ignition lock and remove it. The immobilizer is activated. ...

    Service and literature
    Your vehicle is covered under the terms of the warranties printed in the Service and Warranty Information booklet. Your authorized Mercedes-Benz Center will exchange or repair any defective parts ...

    BAS (Brake Assist System)
    Observe the "Important safety notes" section. BAS operates in emergency braking situations. If you depress the brake pedal quickly, BAS automatically boosts the braking force, thus ...