A4623512051095_8

Technical Service Bulletin
46 Audi frequency analysis
46 23 51 2051095/8 September 18, 2023. Supersedes Technical Service Bulletin Group 46 number 22-33 dated
June 9, 2022, for reasons listed below.
Model(s)
Year
All Audi Vehicles 2015 – 2025
VIN Range
Vehicle-Specific Equipment
All
Not Applicable
Condition
REVISION HISTORY
Revision
Date
Purpose
8
-
Revised header (Added model years)
7
06/09/2022
Revised Service (Updated Procedure)
6
05/19/2022
Revised Service (Updated Procedure)
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
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/id1589055470
© 2023 Audi of America, Inc.
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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
Android: https://play.google.com/store/apps/details?id=de.audi.frequenzanalyseapp&gl=DE
Figure 1. Example of Apple Audi Frequency
Analysis App.
© 2023 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)
© 2023 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).
© 2023 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
frequency.
7.
Figure 6. Typical brake squeal frequency recording.
To create an audio file from the frequency app for attachment to a TAC case, follow the steps below (figures
7 – 9).
© 2023 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 the “More” icon.
© 2023 Audi of America, Inc.
Figure 8. Select the desired Audi file
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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.
Additional Information
© 2023 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
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.
©2023 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.
© 2023 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.