Audio System Does Not Recognize Or Cannot Play Music Files From SD Card (GROUP 91, NO. 14-66)

For Scenario A and Scenario B

Scenario A or Scenario B can result from one of the three following causes:

• The file type of the audio file is not supported by the Audi MMI system. 

  Typically, the Audi MMI system supports the following formats (when discussing supported files formats with the customer, refer to the vehicle owner's manual):

  • .mp3 
  • .wav 
  • .wma 
  • .aac 
  • .m4a  (Copyright-protected DRM files are not supported.)
  • .m4b  (Copyright-protected DRM files are not supported. Bookmarks are not supported.)
  • .mp4  (Audio files only. Audio files encoded with Apple lossless encoding are not supported.)
  • .ogg  (MIB only)

  If the file type of the audio file on the SD card is not listed above, the file will not play in the MMI system.

Some model year 2004 - 2009 owner's manuals incorrectly described the .aac file extension as compatible. Some AAC-encoded files are compatible, but files with the .aac extension are not. This error was corrected with model year 2010 owner's manuals.

• The customer added the audio files to the SD card using iTunes on a Mac OS computer, and the vehicle has the base Concert radio system. 

  The SD card has FAT formatting, which is the only type of formatting supported by the Audi MMI system. FAT formatting is not traditionally used by Mac OS, and as a result, Mac OS adds hidden files (Figure 2) to the SD card to ensure that the files can be read on Mac OS computers.

  The base Concert radio system attempts to read these hidden files, but cannot recognize them and may report that they are damaged. The customer may need to scroll down in the file list or change folder levels to display the playable audio files.

• The bit rate encoding of the audio files exceeds the maximum allowed by the Concert radio system. 

  The Concert radio system can only play music files with a maximum bit rate encoding of 320Kbps. If the maximum bit rate encoding of the files exceeds 320Kbps, the file will not play.

  The maximum bit rate encoding of an audio file can be checked with the free software program MediaInfo (Figure 3), which can be downloaded from http://www.sourceforge.net/.

For Scenario C

Scenario C can result from the following cause:

• One vehicle has Audi Concert radio/RNS-E and the other vehicle has MMI 3G/3G+/MIB. 

  The maximum playable bit rate of the Concert & RNS-E radio systems is 320Kbps. However, the maximum playable bit rate of the MMI 3G/3G+ & MIB systems is higher (refer to the owner's manual for details). It is possible that audio files that play on the MMI 3G/3G+ & MIB systems will not play on the Concert & RNS-E radio systems because of the different maximum playable bit rates of the two systems.

For Scenario A and Scenario B

1. Verify that the audio system is working correctly and is capable of playing one of the supported audio types listed in the Technical Background by using a known good SD card with tested files.

   If the known good files play in the customer's vehicle, advise the customer to re-create their audio files in a format that is supported by the Audi MMI system. If possible, demonstrate for the customer how to create playable files. See the attached quick reference guide for instructions for encoding music files in iTunes. If needed, share the guide with the customer.

2. If the customer is experiencing issues with hidden files on the SD card as a result of using iTunes on a Mac OS computer, advise the customer to use the program "OptimUSB". The program can be downloaded from the official Mac App Store. When the program is used after the customer transfers music to the SD card, the program will "clean" the SD card of any hidden files.

For Scenario C

1. Explain the Technical Background of Scenario C to the customer.
2. If the customer would like to re-encode his or her music to a bit rate that is equal to lower than 320Kbs so that it can be played on the Concert & RNS-E radio systems, share the attached quick reference guide for instructions for encoding music files in iTunes.