Technical Service Bulletin
91 Bluetooth call quality issues for caller on other end of call (A6, A7, A8)
91 14 34 2027718/7 April 8, 2014. Supersedes Technical Service Bulletin Group 91 number 14-20 dated January
3, 2014 for reasons listed below.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

A6, A7, A8

2011 - 2013

All

Bluetooth®

Condition
REVISION HISTORY
Revision

Date

Purpose

7

-

6

1/3/2014

Revised Service (Added diagnostic step to reinstall non-damaged microphones)

5

10/31/2013

Revised Service (Added note to call TAC for certain repairs)

Revised header data (Removed model)
Revised Service (Revised instructions; updated web address)

Revised Required Parts and Tools (Changed quantity)
4

6/11/2013

Revised Service (Clarified information)
Revised Warranty (Updated Diagnostic Time)
Revised header data (added model year)

3

11/12/2012

Revised Warranty (Adjusted TUs)

2

8/6/2012

Revised Service

1

10/25/2011

Original publication

When the driver uses the Bluetooth hands-free telephone system to make a call, the listener on the other end
cannot clearly understand the driver. The driver’s voice sounds muffled, as if it is being heard from under water.

Technical Background
The microphone seal was damaged during installation into the roof module.

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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
Production Solution
Improved microphone installation procedure and optimized the
microphone seal, beginning with January 2012 vehicle production.
Microphones with improved seals are at the 03S level or greater
(Figure 1).

Figure 1. Microphones with improved seals.

Service
Tip: This bulletin does not allow for replacement of the microphones unless there is physical damage found
to the rubber seal on the end of the microphone. Because there has been no hardware optimization to the
microphone, replacing a microphone that is not damaged will not improve the sound quality.
Confirm that the sound quality issue is not due to the phone or phone service provider:
1. Ensure that the customer’s phone is an Audi-approved Bluetooth device by checking the list located at
http://audi-intelligence.com/bluetooth/prod/
2. Before making any repairs, road test the vehicle at a minimum speed of 45 mph with the all windows closed.
3. During the road test, verify the call quality issue by making a Bluetooth call to someone at the workshop. Make
sure that the same person will be available to answer another call after any repairs are made so that the call
quality improvement can be verified.
4. If no call quality issues are confirmed during the road test, end all analysis. The issue is most likely due to the
customer’s phone and/or service provider, which can be demonstrated to the customer by using a different
paired phone with a different service provider. If call quality issues are confirmed, proceed with the repair
procedure below.
Remove the trim plate in order to inspect the microphone
1. Remove the roof module from the vehicle according to ElsaWeb>>Repair Manual>> Electrical
System>>Electrical Equipment>>96 Interior Lights, Switches>>Removal and Installation>>Roof Trim Lamps

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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
and Switches.
2. Remove the decorative trim plate from the roof module in order to inspect the seal of the microphone:
For A6 and A7 vehicles:
• Use your fingers to remove the decorative trim from
the base plate. If necessary, gently pry the trim with a
trim stick or bone tool, then finish removing it with
your fingers.
• There are a number of different clips holding the trim
plate to the base plate depending on the trim level of
the vehicle (Figure 2).

Figure 2. Clip location for A6/A7 high-line roof
module (left) and for mid-line roof module (right)
Inspect and replace the microphone
1. Inspect the seal of the microphone for damage:
• There are two splits in the rubber seal. This is
normal as long as the two halves of the seal are
touching each other (Figure 3).

Figure 3. Undamaged seal
• If the two halves of the seal are loose and move
freely, the seal is damaged (Figure 4).

Figure 4. Examples of damaged seals
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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
2. If none of the seals are damaged, reinstall the microphones into the roof module:
• Ensure that the microphones are firmly seated. A loud snap can be heard and felt when the microphone is
fully seated. Reinstall the roof module and retest for the complaint before proceeding with diagnosis. If the
complaint cannot be reproduced, no additional action is necessary.
If any of the seals are damaged, install a replacement
microphone:
• In order to prevent damage to the microphone seal,
install the microphone while the decorative trim is
removed from the base plate. Slowly install the
microphone perpendicular to the base plate (Figure
5). Do not install the microphone at an angle, as this
may pinch the seal (Figures 6 and 7).
• Carefully inspect the new microphone seal after it
has been snapped into place.

Figure 5. Proper installation.

Figure 6. Incorrect installation at an angle, showing a
pinched seal on the left.

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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. Damage caused by a pinched seal.
Complete the repair
1. After the repair, road test the vehicle at a minimum speed of 45 mph with all windows closed.
2. During the road test, verify the call quality issue by making a Bluetooth call to the same person at the workshop
that was called before the repair in order to verify call quality improvement.
3. If the call quality is still poor, call the Technical Assistance Center (TAC).
4. If the seals and microphones are installed properly, continue with diagnosis. Refer to TSB 2026895, 91
Microphone testing tips and TSB 2026888, 91 Bluetooth Phone: Poor call quality.

© 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
Warranty
Claim Type:

Use applicable claim type. If vehicle is outside any warranty, this Technical Service Bulletin
is informational only.

Service Number:

9157

Damage Code:

0010

Labor Operations:

Remove and install interior light

9620 1900

30 TU

Remove and install telephone microphones

9157 1950

10 TU

Extended road test before and after repair

9157 9999

40 TU Max

GFF

No allowance

0 TU

Road test prior to service procedure

0121 0002

10 TU

Road test after service procedure

0121 0004

10 TU

Diagnostic Time:

Technical diagnosis at dealer’s discretion
(Refer to Section 2.2.1.2 and Audi Warranty Online for DADP allowance details)
Claim Comment:

As per TSB # 2027718/7

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures
Manual. Claims are subject to review or audit by Audi Warranty.

Required Parts and Tools
Part Number

Part Description

Quantity

See ETKA

Microphone

As needed

Additional Information
The following Technical Service Bulletin(s) may be necessary to complete this procedure:
•

TSB 2026895, 91 Microphone testing tips

•

TSB 2026888, 91 Bluetooth Phone: Poor call quality

All parts and service references provided in this TSB (2027718) are subject to change and/or removal. Always
check with your Parts Department and service manuals for the latest information.

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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.