This guide explains how to install a Bluetooth music streaming and AUX interface in an Audi equipped with the MMI 2G High infotainment system. The module integrates with the MMI through the MOST fibre-optic network and appears as an additional source under the CD changer menu.
If you are unsure which infotainment system is installed in your Audi, identify it before ordering or connecting the module. Use our Audi MMI identification guide and confirm that your vehicle has MMI 2G High.
What you need for the installation
- Bluetooth and AUX interface compatible with Audi MMI 2G High
- Supplied power and MOST fibre-optic harness
- Radio or CD changer removal keys
- Plastic trim removal tool if required
- A phone with Bluetooth audio support
You can find the compatible Bluetooth and AUX interface for Audi MMI 2G in our store.
Compatibility and requirements
This installation guide is specifically for Audi vehicles equipped with MMI 2G High and a factory CD changer located in the glovebox. The supplied interface works alongside the original changer by connecting to its power supply and MOST fibre-optic wiring.
The interface adds Bluetooth A2DP music streaming and an AUX input. It does not replace the factory hands-free telephone system. Phone calls can therefore continue to use the original Audi Bluetooth system while music is streamed through the additional interface.
Important: Switch off the ignition and allow the MMI system to shut down before disconnecting the CD changer. Do not look directly into an active fibre-optic connector, bend the optical cable sharply or force any connector into place.
Step 1: Locate the factory CD changer
Open the glovebox and locate the factory CD changer. In most MMI 2G High installations, the changer is fitted in the glovebox alongside other infotainment equipment.
Step 2: Remove the CD changer
Insert the appropriate radio removal keys into the slots on both sides of the CD changer. Make sure each key locks into position before pulling the unit forward.
Insert the keys evenly on both sides of the changer.
Carefully pull the changer out far enough to access the connectors at the rear. Avoid pulling or twisting the wiring.
Step 3: Disconnect the power and MOST fibre-optic connectors
At the rear of the CD changer, you will find the electrical power connector and the orange MOST fibre-optic connection. Release the locking tabs before removing the connectors. Do not pull directly on the wires or fibre-optic cable.
Step 4: Connect the Bluetooth interface
Connect the Bluetooth module using the supplied plug-and-play harness:
- Connect the supplied power splitter between the factory wiring and the CD changer.
- Connect the remaining power plug to the Bluetooth interface.
- Connect the supplied MOST fibre-optic splitter according to the direction and arrangement shown on the module’s wiring harness.
- Check that every connector is fully seated and locked.
The MOST network forms a closed optical loop. An incorrectly fitted fibre-optic connector can cause the CD changer, amplifier, navigation or the entire MMI system to stop communicating.
If the MMI does not start after installation, switch the system off and check the direction and seating of every MOST connector.
Step 5: Test the module before refitting the changer
Before pushing the CD changer back into the glovebox, switch on the ignition and allow MMI to start. Test the changer, Bluetooth source and AUX input.
Once everything works correctly, switch the system off again. Arrange the wiring so it cannot be pinched and carefully reinstall the CD changer.
How to select Bluetooth audio in MMI 2G High
Open the audio source menu and select:
CD/TV → Source → CD Changer
Scroll through the available changer sources until the Bluetooth or AUX interface appears. The exact source name may depend on the version of the module.
The Bluetooth device name and pairing code are normally printed on a label attached to the interface. Take a clear photo of this label before placing the module behind the glovebox.
Pairing a phone with the Bluetooth module
- Enable Bluetooth on your phone.
- Search for nearby Bluetooth devices.
- Select the device name printed on the interface label.
- Enter the pairing code from the label if requested.
- Open a music application and begin playback.
- Select the Bluetooth interface under the CD changer sources in MMI.
The module can operate alongside the original Audi hands-free system. If the phone connects to both devices, use the factory Audi connection for telephone calls and the additional interface for media audio.
Troubleshooting
The Bluetooth source does not appear
Check that the interface receives power and that the MOST fibre-optic loop is connected correctly. Restart MMI after checking the wiring.
MMI does not start after installation
This normally indicates an open MOST loop or an incorrectly seated optical connector. Switch off the ignition and inspect both fibre-optic connections. Do not continue switching the system on until the loop has been restored.
The phone connects, but there is no sound
Confirm that the Bluetooth interface is selected as the active CD changer source. Check the media volume on the phone and make sure audio output is assigned to the Bluetooth module.
The factory CD changer no longer works
Inspect the power splitter and the MOST connections. Both the factory changer and Bluetooth interface must be correctly included in the optical loop.
Installation complete
After confirming that Bluetooth audio, AUX and the original CD changer work correctly, place the interface securely behind the glovebox and refit the changer. Make sure the module and wiring cannot move, rattle or become trapped by the glovebox mechanism.
