What are the important things to know about the Mercedes Benz Key?

This blog will cover everything you need to know about your Mercedes Benz car key and answer a few common questions:  what are the changes in the Mercedes Benz car key over the years? What to do if the key is lost? How to tell if your vehicle has a steering lock or not?

What are the important things to know about the Mercedes Benz Key?

Following are some of the important things to know about the Mercedes Benz car key that will help you to unlock its full potential.

  • Button functions
  • Location of key batteries 
  • Operational range
  • Key antennas

All the above-mentioned functions are discussed in more detail below:

  • Button functions

The latest Mercedes Benz keys have three buttons on the keys. They are unlocked, locked and open the trunk gate. One button is located at the back of the key which releases the mechanical key placed inside the key fob. 

There are additional functions built into the key buttons. A long press on the unlock button will trigger the comfort opening function and all the windows including the sunroof will open. A single press will just unlock the doors. 

Similarly, a long press on the lock button will start the comfort closing function and will close any or all windows that are open including the sunroof. Normal press just locks all the doors of the vehicle. There is also a global or selective locking function hidden in the key.

To toggle between the global and selective unlock, press the lock and unlock button simultaneously. The selective unlock will unlock or lock the driver’s door only with a single press of the respective switch. The consecutive second press will unlock or lock the remaining doors.

In a few selected markets, there is an additional panic button which activates all the hazards and security horns inside the vehicle.

  • Location of key batteries 

The latest Mercedes Benz keys use a single DC battery to function. The signals are transmitted over radio waves and hence they consume less power compared to the key of the previous models. 

The old models used a combination of radio and infrared signals. Hence, they needed double batteries to continue functioning for a long time.

To access the key battery,  remove the mechanical key and unclip the rear cover on the key. The battery is installed in a tray that can be pulled out from the side. There is also a low battery indicator LED on the Key fob. Replacing the battery if the Led is active as a low or a dead battery can lead to an inoperative key.

  • Operational range

The operational range of the key is 2 metres. The vehicle can be locked or unlocked once the key is recognised with the operating range. An FM antenna amplifier built into the rear windshield can boost the scanning range if the signal is not strong.

  • Key antennas

There are 4 keyless go antennas on the vehicle. Two antennas are located on either side of the vehicle, one is in the centre console and the last one is located in the luggage compartment. 

The antenna in the centre console also has an integrated inductor coil that can temporarily supply power to the Key fob so that the key can transmit the drive authorization codes even if the battery is completely dead.

What are the changes in the Mercedes Benz car key over the years?

Mercedes-Benz keys have gone through some changes over the years. The key was changed according to the change in the drive authorization generation. Mercedes Benz is currently using the fourth generation in the drive authorization system, some of the old generations were DAS 3, DAS 2a, 2b and Das 1/1a. DAS 1a to DAS 2b used a combination of Key and infrared signals. DAS 3 went through 3 types of key design but the data transmission was done through radio signals. 

Apart from the changes in the drive authorization system generation, the keys also went through various visual changes. Some of the changes include relocating the lock and unlock buttons in order to make them more ergonomic, and the use of chrome inserts and customisable logos on the back cover. 

Internally, there are transmitters as well as receivers needed for the Keyless go systems which let you start your car without ever having to touch your keys. You can also lock or unlock the doors remotely with a push of a button on your fob along with a tap on the capacitive sensors in the door handle. 

There are even more advanced systems like keyless trunk opening and closing, the vehicle can open the trunk gate if it recognizes that the key is left inside the luggage compartment.

The Mercedes Me connect (MMC) has allowed driver authorization from the smartphone of the customer therefore many people don’t even carry around their keys anymore—they simply use their smartphone as both a vehicle fob and digital key.

What to do if the key is lost?

If you lose your car key, the first thing to do is contact the nearest Mercedes Benz dealership. The specialist personnel at the dealership can identify the lost key track and block it. Once the key track is blocked then the lost key cannot be used to gain access to the vehicle.

Mercedes Benz provides 2 keys with the car and a smartphone can also be used for access authorization. When both the keys are lost then a programmed key must be ordered from the dealerships as at least one working key is required to carry out the programming of a spare or additional key.

The blocked key track can be reopened again if you find the lost key. However, it is important to know that if a replacement key has been assigned to the same track then the previous key becomes useless. Therefore, if you think there is a possibility of finding the lost key then get a spare key instead of a replacement key and keep the original key track blocked.

The Mechanical key on the other hand must be ordered from Germany as all the vehicle-specific database is centrally located there. It is not possible to copy the mechanical key from a locksmith as there can be a risk of damaging the key barrel.

Other articles about Mercedes Benz you may be interested in

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What are the competitive advantages of Mercedes Benz in Formula 1 racing?

What are the Million Dollar Cars in Mercedes Benz?


Mercedes Benz uses a very advanced drive authorization system with separate access and drives authorization. It is not possible to drive a vehicle if the presence of a key is not detected in the vehicle. Mercedes Benz also gives close attention to the design of the key as it should feel premium in hands and also be durable to withstand regular use.