What are the functions of the three buttons on a Mercedes-Benz key?

[VanHarper]

Mercedes-Benz keys have three buttons: unlock, lock, and open trunk. In addition to these three buttons, some models have a fourth button on the key, which is a red button added to the three-button configuration. Some red buttons may feature a horn icon or the word "Panic" printed on them. This button is technically referred to as the "car locator button." Below are detailed explanations of the key functions: Working Principle: The car smart key is a control system composed of three components: a transmitter, a remote central locking control module, and a driving authorization system control module, along with related wiring harnesses. This system utilizes advanced Radio Frequency Identification (RFID) technology, automatically locking and unlocking the doors through the chip in the smart card carried by the owner. Anti-Theft Status: When the driver approaches the vehicle within a certain distance, the door locks will automatically unlock and deactivate the anti-theft system. When the driver leaves the vehicle, the door locks will automatically lock and activate the anti-theft status.