Technical Service Bulletin
91 Audio system does not recognize or cannot play music files from SD Card
91 14 66 2020399/3 October 16, 2014. Supersedes Technical Service Bulletin Group 91 number 14-24 dated
January 24, 2014 for reasons listed below.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

All

2009 - 2016

All

MMI 3G/3G/Concert/Symphony/MIB Standard/High

Condition
REVISION HISTORY
Revision

Date

Purpose

3

-

Revised header data (Added A3 and Q3 models)
Revised Technical Background (Updated information)

2

1/24/2014

Revised header data (Added model years)
Revised entire bulletin for clarity

1

4/14/2009

Initial publication

The Audi MMI system will not play audio files from an SD card. One of the following scenarios is present:
• Scenario A: The MMI system does not recognize the audio
files on the SD card.
• Scenario B: The MMI system reports that the audio files on
the SD card are damaged (Figure 1).
• Scenario C: The audio files on the SD card will play on one
Audi vehicle, but will not play on a different Audi vehicle.

Figure 1. Damaged audio file message.
The vehicle is equipped with RNS-E, Concert Radio with SD card slot, MMI3G, MMI3G+, or MIB.

© 2014 Audi of America, Inc.

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All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of
Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior
expressed written permission of the publisher.

Technical Service Bulletin
Technical Background
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.

Figure 2. Hidden files. The file names of hidden
files start with a period.

© 2014 Audi of America, Inc.

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All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of
Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior
expressed written permission of the publisher.

Technical Service Bulletin
• 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/.

Figure 3. File details displayed in the MediaInfo
software. The overall bit rate (top box) is only
267Kbps, but the maximum bit rate (bottom box) is
404Kbps, which exceeds the 320Kbps limit.
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.

Production Solution
Not applicable.

© 2014 Audi of America, Inc.

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All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of
Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior
expressed written permission of the publisher.

Technical Service Bulletin
Service
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.

Warranty
This TSB is informational only and not applicable to any Audi warranty.

Additional Information
All parts and service references provided in this TSB (2020399) are subject to change and/or removal. Always
check with your Parts Department and service manuals for the latest information.

© 2014 Audi of America, Inc.

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All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of
Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior
expressed written permission of the publisher.