See also:

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. ...

Immobilizer
The immobilizer prevents your vehicle from being started without the correct SmartKey. When leaving the vehicle, always take the SmartKey with you and lock the vehicle. The engine can be starte ...

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. Press the locking ...