Reducing the energy consumption of the key
If you do not use the vehicle or a key for an extended period, you may deactivate the KEYLESS START function of the key.
To deactivate:
press the 
button on the key twice in quick succession. The battery indicator lamp on the key lights up twice quickly and once for longer.
To activate:
press any button on the key. When starting the vehicle with the key in the slot in the shift console, the key functions are activated automatically.
Overview of the Mercedes-Benz emergency call system
The Mercedes-Benz emergency call system can help to decisively reduce the time between an accident and the arrival of emergency services at the site of the accident. It helps locate an accident site in places that are difficult to access.
The emergency call can be triggered automatically More.
You also have the option of triggering the emergency call manually More. Only make emergency calls if you or others are in need of rescue. Do not make an emergency call in the event of a breakdown or a similar situation.