Open a Mercedes-Benz with a Dead Key Fob

How to Open a Mercedes-Benz with a Dead Key Fob

This page holds all of the emergency open or back-up open procedures needed for Mercedes-Benz vehicles if the battery in the key fob dies or if there are electrical signals interfering with the fob.

• First, if you are already inside, click here.
• Second, look for video help here!
• Finally, if you need or want another manufacturer, click here.

Retrieving the Mechanical Key

Mercedes-Benz now features two SmartKey styles. The original and most common style is tapered, like the one shown to the right. To retrieve the mechanical key, slide the release catch found near the top of the fob in the direction of the arrow and pull the mechanical key away from the SmartKey (remote control or ‘clicker’).

There much more below and video help here…

In 2017, a second, rounded SmartKey style was introduced in the E-Class sedan, and is shown to the right. It migrated to S-Class sedans in 2018 and is found in all 2018 E-Class models.

Look for a button on the back of the newer key fob. Push the button and pull on the key ring end to remove the mechanical key, as shown in the image to the right.

In 2021, another key fob was added to the S-Class Maybach that looks similar and operates very similarly. It is a little more tapered at the key ring end. Again, push the button on the back and remove the mechanical key.

If the keyhole is visible, use the mechanical key to unlock the driver’s door. This will set off the car’s alarm.  Successfully completing the start process below will turn it off.

G-series wagons have an exposed key hole, so simply insert the mechanical key and turn, and you’re in.

S- and C-Class

However, beginning in 2015 with the S- and C-Class vehicles and extended over time to nearly all models, the keyhole is hidden beneath a cap at the end of the driver’s door handle (below right). The mechanical key will be used a lever to remove the cap to expose the key hole.

Make sure the handle of the mechanical key is pointed away from the paint. Insert the key into the opening (black arrow) underneath the cap as far as it will go. Hold the door handle out. Pull the cap that is now on the mechanical key as straight as possible away from the vehicle until it releases.

Once removed, the key hole is visible and available to insert the key and unlock. As above, this will set off the car’s alarm, which will be taken care of when you successfully complete the start process below.

The 2021 Maybach adds flush door handles. This has now been added to AMG and EQS models in 2023, EQE, E-Class, S-Class and C-Class models in 2024.

The key hole is revealed in the center of the space when the door handle is pulled open. To do this, push the front of the door handle (top image, right). The rear of the handle will pop out. Take hold of the handle and pull. Use the mechanical key in the exposed key cylinder (bottom image, right). Once again, the alarm may sound, but it will go off when the car is started.

CLE Cabriolet and GLC

Finally, the 2023 CLE Cabriolet and 2024 GLC models employ yet another method to hide the key hole. Pulling the driver’s door handle to the open position reveal the key hole underneath the back of the handle. Simply insert the key and turn and you’ll be inside. And yet again, the alarm will likely sound, but it will go off when the car is started.

Click here for video help specific to many Mercedes models and key fobs.

Important
After using the mechanical key, return it to the electronic key fob. The key fob itself may require the mechanical key to be present to operate.

Models examined include A, AMG, B, C, CLA, CLS, E, G, GL, GLA, GLC, GLE, GLK, GLS, GT, M, S, SL, SLC and SLS Class and Series vehicles. Model years 2001, 2002, 2003, 2004, 2005, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, and 2025.

Continue to Part II, Getting Started …

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The information on this website is provided for information sharing purposes only, and should not be used in lieu of an OEM service manual or factory authorized service procedure. We are not in the auto repair business nor do we publish automotive service manuals. Nothing we include on these pages and posts has been reviewed, approved or authorized by any vehicle manufacturer.

Remember that only proper service and repair procedures will ensure the safe and reliable operation of your car. In addition, proper safety procedures and precautions, such as the use of safety goggles, the right tools and the equipment should be followed at all times to eliminate the possibility of personal injury or improper service which could damage the vehicle or compromise its safety.

Technology is always changing and what is current and accurate today may be literally out-of-date and inaccurate tomorrow. And when it comes to the current state of flux in the auto industry, nothing is more true.

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