A4621222051095_4

46 Audi frequency analysis
46 21 22 2051095/4 February 10, 2021. Supersedes Technical Service Bulletin Group 46 number 19-05 dated
March 14, 2019 for reasons listed below.
Model(s)
Year
VIN Range
Vehicle-Specific Equipment
All
2010 - 2022
All
Not Applicable
Condition
REVISION HISTORY
Revision
Date
Purpose
4
-
Revised header (Added model year)
3
03/14/2019
Revised header (Added model year)
Revised Service (Added Step 12)
2
05/14/2018
Revised Service (Updated User ID description)
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, and 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.
Page 1 of 10
© 2021 Audi of America, Inc.
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.
Service
Download the Audi Frequency Analysis App according to the instructions below:
1. Go to Audi B2B App Shop at https://b2bappshop.audi.de.
2. Sign in with your Global (GeKo) User-ID and Password.
3. Click on “Sign In” (Figure 1).
4. Select the type of device: iOS or Android (Figure 2).
Figure 1. Sign in screen.
Figure 2. Select the type of device.
Page 2 of 10
© 2021 Audi of America, Inc.
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.
5. Click on “Install” to start downloading the App (Figure 3).
6. Example of the downloaded App in an iPhone (Figure 4).
Figure 3. Installing the APP.
Figure 4. Example of the downloaded app and app
shop.
Page 3 of 10
© 2021 Audi of America, Inc.
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.
If you receive the following iPhone error message
(Figure 5) “Untrusted Enterprise Developer” after
clicking on the app then follow the Tip below. Skip to
next figure for Android.
Tip: Go to: Phone Settings >> General >>
Profiles & Device Management >> Enterprise
APP>>Audi AG >> Trust Audi AG.
Figure 5. Error message “Untrusted Enterprise
Developer”.
Page 4 of 10
© 2021 Audi of America, Inc.
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.
If you receive the following Android error message
(Figure 6): “This type of file can harm your device. Do
you want to keep Waveform-release-1.9-sign.apk
anyway?”.
Tip: Select “OK” and proceed with the installation
process.
Figure 6. Error message for Android Phone.
7. After opening the app, see the following example of the main screen (Figure 7).
8. To start frequency analysis, select “Record” (Aufnehmen). There are other functions also available: Play
(Abspielen), Cut (Schneiden), and Export (Exportieren) (Figure 8).
Page 5 of 10
© 2021 Audi of America, Inc.
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.
Figure 7. Example of the main screen.
Figure 8. To start the analysis, select Aufnehmen.
9.
You will be able to record the brake squeal from inside or outside the vehicle, depending on conditions.
10.
Example of a typical brake squeal at 1,6 KHz. The red scale can be moved to identify the main frequency
causing the squeal. Be aware that there are a lot of surrounding noises that can disguise the main
frequency focus (Figure 9).
11.
Example of a typical brake squeal at 3,2 KHz. Also at the top right the date is recorded, exact frequency,
and level of noise in dB (Figure 10).
Page 6 of 10
© 2021 Audi of America, Inc.
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.
Figure 9. Other sounds can disguise the main
frequency.
Figure 10. Typical brake squeal frequency recording.
12 To create an audio file from the frequency app for attachment to a TAC case, follow the steps below
.
(Figures 11 - 13).
Page 7 of 10
© 2021 Audi of America, Inc.
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.
Figure 12. Select the desired audio file.
Figure 11. Take a clear sound recording and then
select the “More” icon.
Page 8 of 10
© 2021 Audi of America, Inc.
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.
Figure 13. 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.
Page 9 of 10
© 2021 Audi of America, Inc.
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.
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.
©2021 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.
Page 10 of 10
© 2021 Audi of America, Inc.
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.