See also:

On-board diagnostic interface
WARNING If you connect equipment to the on-board diagnostics interface, it can affect the operation of the vehicle systems. This can impair the operating safety of your vehicle while driving ...

Trailer power supply
The trailer socket of your vehicle is equipped at the factory with a permanent power supply. The permanent power supply is supplied via trailer socket pin 4. You can connect accessories wit ...

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. ...