See also:

Automatic locking feature
The vehicle locks automatically when the ignition is switched on and the wheels of the vehicle are turning at a speed of more than 9 mph (15 km/h). You could therefore be locked out when: - ...

Refrigerant of the air-conditioningsystem
The air-conditioning system is filled with R134a refrigerant and a special PAG lubricant. Never use refrigerant R 12 (CFC) or mineral lubricants. Otherwise, you could damage the air-condition ...

SmartKey battery
Important safety notes It is advisable to have batteries replaced at a qualified specialist workshop, e.g. at an authorized Mercedes-Benz Center. WARNING   Batteries contain toxic and c ...