2011-2017 Audi A5, A6, Q5 & More: Glove Box CD Changer Failure and Component Protection

Is Your Audi MMI Screen Black? The Glove Box CD Changer Might Be Why

If the MMI (Multi Media Interface) screen in your 2012-2013 Audi A6, 2015-2017 Audi A5, 2011-2017 Audi Q5, 2015-2017 Audi S5, 2015-2017 Audi SQ5, 2015 Audi RS5, 2013 Audi S7, or 2012-2013 Audi A7 Quattro has suddenly gone black, is stuck in a reboot loop, or has no sound, a failed glove box CD changer is a common cause. Because this unit is part of a fiber optic loop, its failure can take the whole system down. This guide will help you diagnose the problem, understand the replacement process, and navigate the critical post-installation programming required.

Symptoms of a Failing Audi CD Changer

Failure of this module can present in two ways: problems with the CD changer itself, or problems with the entire MMI system.

• Total MMI System Failure: The most dramatic symptom is a complete MMI system shutdown. The screen may be black and refuse to turn on, or it may constantly reboot. You may also experience a total loss of audio from all sources (radio, navigation, etc.). This happens because the CD changer has failed electronically, creating a break in the MOST fiber optic loop that connects all the media components.
• "Device Fault" Message: The MMI screen may display a "Device Fault" error when you try to select the CD changer.
• Mechanical Failure: The unit may make grinding or clicking noises, refuse to accept or eject discs, or indicate that no discs are present when the magazine is full. Using homemade CDs with paper labels is a known cause of mechanical jams.
• Blinking Lights: The indicator lights on the front of the CD changer may blink erratically.
• No Power: The lights on the unit may not illuminate at all, indicating a loss of power to the unit itself.

How to Diagnose the Problem

If your entire MMI system is dead, you need to determine which component on the fiber optic loop has failed. The most effective DIY method is using a fiber optic bypass loop.

1. Purchase a MOST Bypass Loop: These are inexpensive tools, sometimes called "lollipop testers," available online. They allow you to complete the fiber optic circuit while removing one component from it.
2. Access the CD Changer: Open the glove box. The CD changer is the unit with the disc slots.
3. Remove the Unit: You will need a set of radio removal keys (often sold as Metra 86-9001). Insert the keys into the two horizontal slots on the face of the unit until they click. This releases the internal clips, and you can then pull the unit out of the glove box.
🎬 See this walkthrough on how to remove the glove box CD changer
4. Install the Bypass Loop: Disconnect the main wiring harness from the back of the CD changer. This harness contains both power wires and the fiber optic cable (typically a pair of orange fibers with a black connector). Carefully separate the fiber optic connector from the main plug. Plug the bypass loop into this fiber optic connector, completing the circuit.
🎬 Watch: How to use an optical loop to isolate broken MMI devices
5. Test the System: Turn on the ignition. If the MMI screen powers on and the radio starts working, you have confirmed that the CD changer was the cause of the failure. If the system is still dead, the failure is with another module (like the amplifier or radio tuner, often located in the trunk), and you will need to repeat this bypass process on each module until the system powers on.

Buying a Used Audi CD Changer: The Component Protection Trap

This is the most important part of this guide. You cannot simply swap in a used CD changer and expect it to work. Audi uses an anti-theft system called Component Protection (CP) on most of its electronic modules.

• What is Component Protection? When a module like this CD changer is installed in a vehicle at the factory, it is electronically "married" to that car's unique Vehicle Identification Number (VIN).
• What Happens When You Install a Used Part? When you install a used CD changer from another vehicle, your car's central gateway module detects that the component is from a different VIN. It will then activate Component Protection.
• Symptoms of Active CP: The MMI will display a message like "Component Protection active," and the CD changer will have limited or no functionality. You may get sound for only a few seconds, or none at all.

How to Remove Component Protection

Component Protection must be removed online by connecting to Audi's factory servers. This pairs the "new" used part to your vehicle's VIN.

• Audi Dealer: Any Audi dealer can perform this service. They will connect their ODIS diagnostic system to your car and run the adaptation routine. This typically costs the equivalent of one hour of shop labor.
• Specialized Independent Shop: Some independent European auto repair shops have the licensed tools (like ODIS with GEKO online access) and subscriptions to perform this service. This can be a more cost-effective option than the dealer.
• DIY Tools: Standard DIY tools like VCDS (VAG-COM) cannot remove Component Protection. Some advanced, often cloned, tools claim to, but results can be unreliable and may cause further issues. It is strongly recommended to have this done by a dealer or a qualified specialist.

Cost Comparison

Known Issues, TSBs, and Recalls

There are no known recalls for this specific CD changer. One informational Technical Service Bulletin (TSB 91 13 91 / 2031367) was issued to address a non-issue: on MMI 3G+ systems, the changer will not automatically advance to the next disc if the "Repeat" function is enabled in the settings. This is normal operation and not a fault. Other MMI-related TSBs exist for software updates to fix various bugs, but none point to a widespread manufacturing defect in the CD changer itself.

Frequently Asked Questions (FAQ)