See also:

Warning and indicator lamps
  ...

Locking the vehicle (mechanical key)
If the vehicle can no longer be locked with the SmartKey, use the mechanical key. •► Open the driver's door.•► Close the front-passenger door, the rear doors and the trunk lid/tailgat ...

Please bear the following in mind
At the onset of winter, have your vehicle winterproofed at a qualified specialist workshop, e.g. at an authorized Mercedes- Benz Center. Observe the notes in the "Changing a wheel" se ...