Technical Service Bulletin
46 Audi frequency analysis
46 22 31 2051095/6 May 19, 2022. Supersedes Technical Service Bulletin Group 46 number 22-28 dated
February 22, 2022, for reasons listed below.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

All

2010 –
2013

All

Not Applicable

Condition
REVISION HISTORY
Revision

Date

Purpose

6

-

Revised Service (Updated Procedure)

5

02/22/2022

Revised header (Added model year)

4

02/10/2021

Revised header (Added model year)

This bulletin is informational only and can help technicians to identify noise frequency for specific concerns related
to the brake system, especially brake squeal.

Technical Background
Brake squeal is the most common brake noise concern received from customers. This bulletin will help you to
identify the correct frequency for the concern.
Knowing the exact frequency can help Audi of America to understand the issue and find a feasible solution (for
example new pad materials, new pad geometry, new backing plate, new spring design, balance weight, etc.).
Remember that brake squeal is a normal result of multiple factors acting on the brake system.
Brake squeal is not a defect.

Production Solution
© 2021 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
Not applicable.

Service
1.

Download the Audi Frequency Analysis App according to the instructions below:
Apple: https://apps.apple.com/us/app/audi-frequency-analysis/id/1589055420
Android: https://play.google.com/store/apps/details?id=de.audi.frequenzanalyseapp&gl=DE

Figure 1. Example of Apple Audi Frequency
Analysis App.

© 2021 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
If you receive the following iPhone error message (Figure 2) “
Untrusted Enterprise Developer” after clicking on the app
then follow the tip below.
Tip: Go to: Phone Settings >> General >> Profiles &

Device Management >> Enterprise APP >> Audi AG >>
Trust Audi AG.

Figure 2. Error message “Untrusted Enterprise
Developer”.

2.

After opening app, see the following example of the main screen, see the following example of the main
screen (Figure 3).

3.

To start frequency analysis, select “Record” (Aufnehmen). There are other functions also available (Figure 4):
• Play (Abspielen)
• Cut (Schneiden)
• Export (Exportiernen)

© 2021 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

Figure 3. Example of the main screen.

Figure 4. To start the analysis, select Aufnehmen.

4.

You will be able to record the brake squeal from inside or outside the vehicle, depending on conditions.

5.

Example of a typical brake squeal at 1.6 KHz. The red scale can be moved to identify the main frequency
causing the brake squeal. Be aware that there are a lot of surrounding noises that can disguise the main
frequency focus (Figure 5).

6.

Example of a typical brake squeal at 3.2 KHz. Also at the top right the date is recorded, the exact frequency,
and the level of noise in dB (Figure 6).

© 2021 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

Figure 5. Other sounds can disguise the main

Figure 6. Typical brake squeal frequency recording.

frequency.

7.

To create an audio file from the frequency app for attachment to a TAC case, follow the steps below (figures
7 – 9).

© 2021 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

Figure 7. Take a clear sound recording and then select

Figure 8. Select the desired Audi file

the “More” icon.

© 2021 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

Figure 9. Then select “Exportieren (Export)” and send the file to the source used to attach the document to a
TAC Case.

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

© 2021 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
Additional Information
All parts and service references provided in this TSB (2051095) are subject to change and/or removal. Always check
with your Parts Department and/or ETKA for the latest information and parts bulletins. Please check the Repair
Manual for fasteners, bolts, nuts, and screws that require replacement during the repair.
©2022 Audi of America, Inc. All rights reserved. The 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.

© 2021 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.