Mercedes-Benz C-Class (W205) 2015 - 2021 Owners Manual: SmartKey

Overview of SmartKey functions

1. Locks
2. Battery check lamp
3. Unlocks
4. Opens/closes the trunk lid
5. Panic alarm

The SmartKey may vary from the one shown in the diagram, depending on the vehicle equipment.

The SmartKey locks and unlocks the following components:

• the doors
• the trunk lid
• the fuel filler flap

If the vehicle is not opened within approximately 40 seconds after unlocking, it locks again. Antitheft protection is activated again.

Do not keep the SmartKey together with electronic devices or metal objects. This can affect the SmartKey's functionality.

battery check lamp 2 does not light up after pressing the or button, the battery is discharged.

Replacing the SmartKey battery.

Activating/deactivating the acoustic locking verification signal

Multimedia system:

Vehicle → Vehicle Settings → Acoustic Lock

• Activate or deactivate the function.

Activating/deactivating the panic alarm

Requirements:

• The ignition is switched off

The panic alarm function is only available in certain countries.

• To activate: press button 1 for approximately one second.

  A visual and audible alarm is triggered.

• To deactivate: briefly press button 1 again.

  or

• Press the start/stop button on the cockpit (the SmartKey is inside the vehicle).

Changing the unlocking settings

Possible unlocking functions of the SmartKey:

• Central unlocking
• Unlocking the driver's door and fuel filler flap

• To switch between settings: press the and buttons simultaneously for approximately six seconds until the battery check lamp flashes twice.

If the unlocking function for the driver's door and fuel filler flap has been selected:

• Pressing the button a second time centrally unlocks the vehicle
• Vehicles with KEYLESS-GO: If you touch the inner surface of the door handle on the driver's door, only the driver's door and fuel filler flap are unlocked.

Deactivating the SmartKey functions

If you do not use the vehicle or a SmartKey for an extended period of time, you can reduce the energy consumption of the respective SmartKey . To do so, deactivate the SmartKey functions.

• To deactivate: press the&button on the SmartKey twice in quick succession.

  The battery check lamp of the SmartKey flashes twice briefly and lights up once.

• To activate: press any button on the SmartKey.

When the vehicle is started with the SmartKey in the stowage compartment of the center console, the SmartKey functions are automatically activated .

Removing/inserting the emergency key

• To remove: press release button 1.

  Emergency key 2 is pushed out slightly.

• Pull out emergency key 2 until it engages in the intermediate position.

You can use the intermediate position of emergency key 2 to attach the SmartKey to a key ring.

• Press release button 1 again and fully remove emergency key 2.
• To insert: press release button 1.
• Insert emergency key 2 to the intermediate position or fully until it engages.

Replacing the SmartKey battery

ENVIRONMENTAL NOTE Environmental damage caused by improper disposal of batteries

Batteries contain pollutants. It is illegal to dispose of them with the household rubbish. Dispose of batteries in an environmentally responsible manner. Take discharged batteries to a qualified specialist workshop or to a collection point for used batteries.

Requirements:

• You require a CR 2032 3 V cell battery.

Mercedes-Benz recommends that you have the battery replaced at a qualified specialist workshop.

• Remove the emergency key.

• Press release button 2 down fully and slide cover 1 in the direction of the arrow.
• Fold out cover 1 in the direction of the arrow and remove.
• Remove battery compartment 3 and take out the discharged battery.
• Insert the new battery into battery compartment 3. Observe the positive pole marking in the battery compartment and on the battery when doing this.
• Push in battery compartment 3.
• Re-attach cover 1 and push it until it engages.

Problems with the SmartKey