Have you locked the keys inside the trunk of your Mercedes-Benz? Maybe your key fob isn’t working or car battery is dead and you are trying to unlock the trunk of your Mercedes-Benz. If your car battery is dead or the key fob remote has stopped working, you won’t be able to unlock your Mercedes-Benz or open the trunk.

In this article:

  • How to open Mercedes-Benz trunk when the battery is dead
  • How to unlock trunk when the key is not working
  • Keys locked in the trunk How to open Mercedes trunk.

How to manually unlock the trunk of a Mercedes-Benz

If your Mercedes battery has died, trunk switch or key fob remote aren’t working, you can use this method to unlock the trunk.

Step 1 

Remove the metal key from the key fob. You will need to slide the locking tab with your thumb and pull out the metal key.

Step 2

Insert the key into the trunk lock cylinder.

Step 3

Turn the key until you hear the trunk pop open.

Note: Avoid jump starting your Mercedes-Benz by connecting the jumper cables directly to the battery. Instead, use the positive jumper starter terminal located in the jumper cable.

How to open the trunk if trunk if the key isn’t working or keys are locked in the trunk.

What if you started replacing the battery in the trunk and you accidentally locked the keys inside the trunk. Now you are wondering how can I open the trunk? Here are a few similar scenarios.

  • The car battery has died and the battery is in the trunk.
  • You locked the keys in the trunk and the battery is dead.
  • Or you tried to manually unlock the trunk but can’t turn the key manually.

So what do you do? Luckily, there is another way to power up your Mercedes-Benz.



Get a locksmith to open one of the doors then follow these steps.

Step 1

Release hood by pulling on the hood release lever on the side of the dashboard.


Next, open the hood. 

Step 2

All Mercedes-Benz model year 2000 and newer have a jump start terminal inside the engine bay. Regardless if the battery is in the trunk or under the rear seat. Locate the positive jump starting terminal. This is how the positive jump start terminal looks on an E-Class W210

Here is another example. 

Step 3

Connect a jump box positive terminal to the positive terminal and the negative jumper cable to a ground point or frame. Alternativly instead of a jumper cable 

Now you can press the Lock/Unlock buttons on your Mercedes-Benz key fob remote to unlock the car or the trunk. You can even start the car this way.