See also:

Unlocking the driver's door (mechanical key)
If the vehicle can no longer be unlocked with the SmartKey, use the mechanical key. If you use the mechanical key to unlock and open the driver's door, the anti-theft alarm system will be tri ...

Overhead control panel
  ...

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-Be ...