Mercedes Bluetooth-Audio Fix | Most 2008 – 2017 models | “BT Audio” Activation!

If you have a Mercedes-Benz model equipped with the Bluetooth Phone, but can’t find Bluetooth Audio – read this! “BT Audio” is designed for the streaming of audio from your phone, or any device compatible with a Bluetooth technology. A lot of people contacted me with the same problem, so I decided to write an article with the solution to this problem, which will require to enter the Mercedes “Engineering mode”.

Mercedes Bluetooth Audio

First, you have to make sure that Bluetooth is active in your car. On your screen, go to SYSTEM and then to SYSTEM SETTINGS, then make sure that ACTIVATE BLUETOOTH box is selected. Same as in photo below:

Mercedes Bluetooth Menu

Then go to AUDIO on the screen and select it. One of the menus in the AUDIO has to be “Bluetooth Audio”, but if you don’t see this menu on the screen (like on the photo below), then you need to enter the system Engineering Mode.

Mercedes Audio Menu

In order to enter the system Engineering Mode, you have to press and hold 3 buttons for about 5-6 seconds until you see the Engineering Mode menu pops up on the screen. The 3 buttons to press together are: RED PHONE PICKUP button + “1” button + “#” button. The buttons are highlighted on the photo below:

Mercedes Engineering Menu

Once you enter the engineering mode on the screen, scroll down to “HU Parameter” and enter. There you’ll see 2 selections: “BT Audio” and “Bluetooth” as you can see in the photo below. Make sure to turn both of them ON.

IMPORTANT: If both selections are turned on already, make sure to turn them off completely… and then turn them on again. Now you can exit from there, and at this point you should have BT Audio selection appeared under AUDIO menu. However,

If all these steps didn’t help and you’re still missing the Bluetooth Audio, here at, we recommend to reset the whole system entirely. Go to SYSTEM SETTINGS and scroll down to RESET, as you can see in the photo below. NOTE: If you do a total reset, you’ll lose all your presets and memory for the radio, navigation, phone etc., so everything will need to be setup again from scratch.

Mercedes Reset

Thanks to Nart Roustom for providing some of the images.

34 Replies to “Mercedes Bluetooth-Audio Fix | Most 2008 – 2017 models | “BT Audio” Activation!”

      1. I got aftermarket interface for my Mercedes Benz c300 2011 model and the problem is only one side speakers works but other side don’t work! I tried 7 different devices but still not the results I want! Can someone please help

        1. Did you try to adjust the “Volume Balance” in the Audio settings of AUX input, and move it to the middle?

          1. Yes I did! I tried almost everything possible. It works great on FM or DISC but when I use media interface (external Bluetooth) it only works on right side!

  1. Please when I entered the engineering mode, my car ( Glk350 2012), did not show BT audio instead it showed others but BT audio not included under the HU parameter

    1. This particular model probably doesn’t have BT Audio streaming. But I think it used to have a Media Interface inside the glove compartment, which consisted of an old iPod connector and also AUX input. Check inside the glove compartment if you still have this plug on the left side inside. If you do, then there are a lot of companies making the interface dongles to enable BT Audio streaming. Just search for any of them online.

    1. The first Mercedes-Benz with Apple CarPlay was released in 2016 models, but the first with Android Auto was released for 2017 models. That’s when I released my first video Mercedes Android Auto because of all the confusion. The only way to get Android Auto is to trade your vehicle for a newer one. The stock Navigation is pretty good, but I would recommend performing a map update at the dealership. You can stream all the sound via Bluetooth media as I’ve shown in Part 4 of the Mercedes Video Manual.

        1. Smartphone Integration was optional on 2019 GLC and became the standard equipment starting from 2020 models. I can check if your particular model had this option if you give me VIN# of your vehicle (if you live in the U.S.). Or you can check yourself. Make sure you use the right USB input, as it doesn’t work with all the USB’s in your car. You can watch how I connected Android Auto (Apple CarPlay connects the same way) to 2017 GLS450 here: Mercedes Android Auto.

  2. Bonjour je vies d’acheter un ML de 2010, j’ai bien raccordé mon téléphone en BT mais uniquement pour les appels, cela ne fonctionne pas pour la musique, je suis rentrée dans le mode ingénieur (6+*+raccrocher pour moi) mais je n’ai pas trouvé comment activer le BT pour la musique
    La version NTG2.5
    Auriez vous un conseil à me donner ?

    1. If I’m not mistaken, 2010 ML didn’t have the Bluetooth audio streaming yet. There are some companies who make an interface dongle for this model, enabling you to stream over the Bluetooth connection. Just do a little search online.

  3. I tried to hit those 3 buttons together and it’s not accessing the engineering mode in my 2011 S550. Is there a different way to access the engineering mode for the S550?

  4. Found BT Audio in engineering mode in my e250 2009 and turned it on. But still didn’t show up in audio options? Hope you’re still replying!

    1. Make sure to checkmark “Activate Bluetooth” as I’ve shown in this article as a first step in the first photo.

    1. I haven’t done it, but try to “TURN OFF DISPLAY” from your central screen selection. Then hit the central mouse, the seat button (on the right of the hazards button), and the mute button (in the center console next to the mouse on the right side). Press all 3 and hold about 5 seconds. Let me know if it worked.

  5. Took all steps as described in article, Bluetooth audio shows as available, however, on the Bluetooth screen it will not let me scroll to the button that says “connect dev”. Any assistance in order to get this working would be of great help.

    1. As long as Bluetooth Audio is active, and your phone is connected via Bluetooth, you need to go to Media and start streaming audio.

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