See also:

Checking tire pressure electronically
  Make sure that the SmartKey is in position 2 in the ignition lock.   Press the or button on the steering wheel to select the Service menu.   Press the or button to sel ...

Important safety notes
Do not leave the SmartKey in the trunk/cargo compartment. You could otherwise lock yourself out. WARNING When leaving the vehicle, always remove the SmartKey from the ignition lock. Always ...

Cleaning the steering wheel and gear or selector lever
– Thoroughly wipe with a damp cloth or use leather care agents that have been recommended and approved by Mercedes- Benz. ...