How to open a Mercedes Benz trunk without a key?
By
Vroomouk
This blog will explain different ways you can open a Mercedes Benz trunk without a key and answer the following questions: how to manually unlock the trunk in a Mercedes Benz? what to do if the key to your Mercedes Benz key is lost? What are the common problems with tailgates of Mercedes Benz cars?
How to open a Mercedes Benz trunk without a key?
A Mercedes Benz trunk can be opened without a key by the following methods:
- Emergency release lever
- Actuating the trunk Lock
- Removing the trunk panel
- Mercedes Me connect app
Let’s take a look at the detailed process to open the trunk:
Emergency release lever.
Mercedes Benz trunks have an emergency release lever for the trunk lock actuator. The location of the emergency release lever is given in the owner’s manual. Usually, it is present on the inside panel of the tailgate.
Simply move the release lever in the direction of the arrow and lift it upwards, the actuator will be mechanically unlocked. The release lever is connected to the tailgate lock by a cable hence it will work even if the main battery is completely dead.
To use this method, the vehicle must be unlocked as the release lever is present on the inside of the tailgate. Once the lock is open it is possible to lift the tailgate and access the trunk, if the trunk is closed again then it will be locked again.
The emergency lever is present on only selected models so if there is no location given in the owner’s manual, try the other methods.
Actuating the trunk lock.
Mercedes Benz uses an electronic actuator to open and close the trunk latch. If the vehicle is unlocked it is possible to connect an OBD-II scanner and actuate the lock from the rear signal actuation and acquisition control unit.
Similarly, the electronic lock uses a power supply from a fuse box so it is possible to locate a fuse and provide an external power supply to the lock actuator. The information and the location of the fuse are provided on the leaflet in the fuse box panel.
When giving an external power supply, it is recommended to install a 5 A fuse in the electrical lines to prevent damage to the electric circuit. This method will only work if the location of the fuse is in the A-pillar or vehicle interior fuse box.
Removing the trunk panel
It is possible to open the trunk by removing the panel on the trunk lid, there is no need to unlock the vehicle for this process to work. However, the panel on the trunk will need replacement as it gets damaged in the process.
The license plate is removed to access the screws of the panel, there are additional screws from the inside which must be carefully separated from the outer panel. Once the panel is removed, the locking barrel can be easily pressed to open the trunk without a key.
There is no mechanical lock in the latest Mercedes Benz vehicles so it is not possible to unlock the trunk if the main battery is discharged or the locking actuator goes bad. Access to the trunk is gained from the rear seats and then it is possible to open the trunk from the inside. There is a hole in the electronic actuator to move the latch.
Mercedes Me connect app
If the vehicle is paired to the smartphone of the customer, then the trunk can be opened by selecting the unlock menu from the smartphone Mercedes Me connect app. Mercedes Me connect gives remote access to the customer via a smartphone.
There is an electronic sim card in the vehicle which is connected to a 4G network. The Mercedes Me connect app needs a network to lock or unlock the vehicle. Therefore, this method can only work if the vehicle has a mobile network.
Customers can also unlock the doors and roll the windows and on some models, it is possible to drive the car for a few meters. This feature is present in selected markets and the smartphone must be registered as an additional key in the Mercedes Benz drive authorization system.
How to manually unlock the trunk in a Mercedes Benz?
In order to manually unlock the trunk in a Mercedes Benz car, remove the mechanical key from the key fob. Locate the key barrel on the trunk lid, and insert the key into the barrel. Turn the key clockwise until the lock is open.
It is also possible to permanently lock the trunk by turning the key anti-clockwise. If the mechanical lock is in lock position then it is not possible to open the trunk by actuating the trunk open switch in the handle. Also, the trunk open switch on the key will not work. Hence, when removing the key, always ensure the position of the mechanical key barrel is neutral.
what to do if the key to your Mercedes Benz key is lost?
If your Mercedes Benz car key is lost then report to any authorized workshop with the spare key of the vehicle. The authorized workshop can temporarily block access to the lost key. If you are certain that the key is permanently lost, Mercedes Benz gives the option to have up to two replacement keys.
Customers can also choose to have up to 8 additional keys to the vehicle. The programming time of the key can vary depending on the generation of the drive authorization system. If the vehicle has the fourth-generation of drive authorization system then the dealership can program a replacement key if a blank key is available in the stock.
The keys of the das 3 cannot be programmed at the dealership as a special key station is required to read and transfer the data into the new key.
What are the common problems with tailgates of Mercedes Benz cars?
The common problems with the tailgate of Mercedes Benz cars are given below:
- Lock actuator- it is the most common part that goes wrong in the trunk locking mechanism.
- Trunk handle – the trunk release switch is located in the trunk handle, if the switch does not send the actuation signal then the rear SAM will not unlock the switch.
- Tailgate motor- the motor is present in one of the support struts of the tailgate, it opens and closes the tailgate automatically after pressing the switch. This motor fails due to an internal fault and the tailgate cannot be opened.
Conclusion
This blog listed the methods that can be used to open the trunk of a Mercedes Benz without a key. The latest cars have no emergency release lever and mechanical lock, therefore opening the trunk without the key needs a specialized person in the authorized workshop.
