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:

    Roadside Assistance button
    Open the stowage compartment under the armrest. Press and hold Roadside Assistance button 1 for more than two seconds. This initiates a call to the Mercedes-Benz Customer Assistance Center ...

    Back button
    Press briefly: - Back - Switches off the Voice Control System - Hides display messages or calls up the last Trip menu function used - Exits the telephone book/redial memory ...

    Socket in the front-compartment center console
    To open: slide cover 1 forwards until it engages. Lift up the cover of socket 2. To close: press cover 1 briefly at the front. The cover moves back. ...